Antilock brake system on their ride?

[ONDSKAN]

Am I crazy to want ABS on my 800hp BB Chevy?:machine:

[Norm Peterson]

The primary benefit of ABS is that you can brake hard and still steer. Generally, this implies accident avoidance. Help any?

Crazy might be if you expect to be able to bolt some factory ABS system and its calibration into a car whose weight, weight distribution, CG height, tire sizes, etc. are any more than just a little bit different from your car. Designing/calibrating your own would probably be a huge effort.


Norm

[68Formula]

The primary benefit of ABS is that you can brake hard and still steer. Generally, this implies accident avoidance. Help any?

Crazy might be if you expect to be able to bolt some factory ABS system and its calibration into a car whose weight, weight distribution, CG height, tire sizes, etc. are any more than just a little bit different from your car. Designing/calibrating your own would probably be a huge effort.


Norm

That's why the OEMs have experienced engineers spending months calibrating systems, while simulating every potential condition and dynamics (temperature, humidity, friction surface, bumps, etc) the vehicle can encounter.

An improperly calibrated system can not only increase braking distances, but cause a loss of vehicle control.

You would be better off focusing on a strong non-ABS braking system, suspension, and tires that will perform in wet and dry condition.

[Tuske427]

What about grafting a system from a similar sized/ weighted car? I would think (and I'm only guessing here) that if an ABS is designed to accommodate a variety of conditions, wouldn't it be logical to believe that it would work on a similar car? After all, they are designed to keep the wheels from locking up. I'd think it would be most important to make sure the components are attached and functioning properly. This way they can accurately monitor wheel rotation and respond accordingly.

Just a thought. I hope it helps.

[John Wright]

What about grafting a system from a similar sized/ weighted car? I would think (and I'm only guessing here) that if an ABS is designed to accommodate a variety of conditions, wouldn't it be logical to believe that it would work on a similar car? After all, they are designed to keep the wheels from locking up. I'd think it would be most important to make sure the components are attached and functioning properly. This way they can accurately monitor wheel rotation and respond accordingly.

Just a thought. I hope it helps.
Once you have adapted larger brakes and tires or changed anything from what the factory orginally had...the calibrations are out the window. Imagine that you upgraded just the brakes and tires....the car will now transfer alot more weight and unload the rear tires...will the ABS know how to compensate for that without a recal?

[93Polo]

I upgraded the brakes on my 93 Corvette from 12" to 13" Grand Sport Calipers without problems. I also upgraded my C5 from factory to 4 piston Brembo 993 Turbo calipers (Big Reds) and never had a problem. Both vehicles also had changes in shocks, wheels and tires.

The main job of the ABS is to keep the wheels from locking up. ABS has to be very dynamic due to all the factors which cause loading and unloading of each corner which include the road, speed, cornering, tires, chassis, etc etc. ABS brake systems still have a proportioning valve which is often changed on C4s and other vehicles without recalc of the ABS.

It is not my expereince that one or even multiple upgrades toss the program out the window. Further on top of the upgrades I have done, many have kept ABS after weight reductions or adding a few hundred pounds with forced induction and/or swapping to an iron block without need to reprogram the system.

I would like to see more using GM ABS systems on their older cars and what those that have the systems have done to get them working.

[Yoda4561]

I'd certainly be interested in more hard numbers on this. Thinking about it logically a good modern ABS system should be pretty resilient to changing vehicle conditions, after all it wouldn't do for a few passengers or a few heavy items in the trunk to throw off the whole control program. Not to mention tires, different brake pads, and various road conditions from dry pavement to dirt to ice. And a well balanced pro touring car isn't that far off weight wise from most modern rwd cars, not enough I'd think to negatively affect an ABS system off of a similar weight vehicle. By that line of thought depending on the particulars of the PT car anything from a vette, 5th gen, or even light truck should work without much issue.

[HWYSTR]

Again, look at the purpose of a ABS system, which in theory is to aid an inexperienced driver in a panic situation to avoid loosing traction/control when braking. For an experienced driver, it does nothing but increase stopping/braking distances. Which is why F1 cars don't have ABS in my opinion.


.

[silver69camaro]

I use ABS on my Camaro. It works extremely well and allows me to brake much deeper into a corner than before. To make it work, it took lots and lots, and a little more, research.

A few things I'd like to point out:

-ABS systems are mostly intended to keep a vehicle in control while braking. Some cars use systems that are more geared towards reducing stopping distances - these are the pump assemblies you want. Think Z06.

-Some formula cars do use ABS when rules allow...because it works.

-The reason why the donor vehicle needs to be very, very similar to the recipient vehicle being retrofitted is because the EBCM (Electronic brake control module) tries to prevent lockup. It tries to predict the wheels locking before it actually happens.

-If the brake systems is vastly different than the donor car, it wont work as well as it should. The pump is programed with a relationship fluid pressure to wheel deacceleration. If it takes more additional pressure than it should to slow the vehicle, the EBCM will freak out.

When you experience a ABS system with fat tires and big brakes, you'll change your mind about it only being for sissies. If you've ever flat-spotted a tire, you'll enjoy ABS.

[silver69camaro]

You would be better off focusing on a strong non-ABS braking system, suspension, and tires that will perform in wet and dry condition.

For 99.9% of enthusiasts, I would say that's true. It isn't for everybody!

[HWYSTR]

Hm, maybe I need to re-think it then, because several years ago when I did some initial homework on the subject, I came to the conclusion as I stated above. This is after talking to a number of circuit racers as well.

What brought my initial interest around was when I switched to ATS's spindles, which have the sensor brackets already. My focus at the time was more as to 'why' and 'if' I wanted to go ABS or not.

True, Z06 does have ABS, though do the C5/6 R's have them too? I'd be surprised, though don't know for sure. May be because it's not allowed in that class if they don't, I just don't know. Would drivers want it? Again, I don't know, but my initial feeling is no.

I've driven so many years without ABS on performance cars, all kinds, to the edge, and if I WERE to go to ABS, I believe it would require a new or 'adjusted' technique. I can see where it could be beneficial, as in a turn where a tire is lifted, just not sure for the rest of the track how beneficial it would be.

I'd be curious to hear more about your findings silver69....

.

[93Polo]

Hm, maybe I need to re-think it then, because several years ago when I did some initial homework on the subject, I came to the conclusion as I stated above. This is after talking to a number of circuit racers as well.

What brought my initial interest around was when I switched to ATS's spindles, which have the sensor brackets already. My focus at the time was more as to 'why' and 'if' I wanted to go ABS or not.

True, Z06 does have ABS, though do the C5/6 R's have them too? I'd be surprised, though don't know for sure. May be because it's not allowed in that class if they don't, I just don't know. Would drivers want it? Again, I don't know, but my initial feeling is no.

I've driven so many years without ABS on performance cars, all kinds, to the edge, and if I WERE to go to ABS, I believe it would require a new or 'adjusted' technique. I can see where it could be beneficial, as in a turn where a tire is lifted, just not sure for the rest of the track how beneficial it would be.

I'd be curious to hear more about your findings silver69....

.


A few years ago in Speed World Challenge Racing, ABS created a big debate as some cars were allowed to have it and other weren't. Having ABS was viewed as an advantage.

F1 does not allow ABS due to cost and effort required by the sanctioning body to monitor that the system is only used for ABS.


Driving technique would not have to be changed, if anything having ABS can make your technique lazy as you have an extra safety net and pedal pressure does not have to be near as precise. On the flip side if you want to push it 110% you can brake later without fear of lockup.

I can remember a few times in my C5, C4, and 4th Gen Z28 where ABS really helped save my but. If I did not have ABS I may have been fine but it would have required more effort on my part.

[93Polo]

I use ABS on my Camaro. It works extremely well and allows me to brake much deeper into a corner than before. To make it work, it took lots and lots, and a little more, research.

A few things I'd like to point out:

-ABS systems are mostly intended to keep a vehicle in control while braking. Some cars use systems that are more geared towards reducing stopping distances - these are the pump assemblies you want. Think Z06.

-Some formula cars do use ABS when rules allow...because it works.

-The reason why the donor vehicle needs to be very, very similar to the recipient vehicle being retrofitted is because the EBCM (Electronic brake control module) tries to prevent lockup. It tries to predict the wheels locking before it actually happens.

-If the brake systems is vastly different than the donor car, it wont work as well as it should. The pump is programed with a relationship fluid pressure to wheel deacceleration. If it takes more additional pressure than it should to slow the vehicle, the EBCM will freak out.

When you experience a ABS system with fat tires and big brakes, you'll change your mind about it only being for sissies. If you've ever flat-spotted a tire, you'll enjoy ABS.

Agreed, Also good point about flat spotting tires, it can happen to even the best from time to time. A friend was a Viper Tech when Road Atlanta still had Panoz run track days and I remember going up to the track with some of his customers who flat spotted 315 Hoosiers on the front. It really isn't to hard to do if a car in front of you does something unexpected and your car has fat tires and big brakes. I've also been in C5/C6s with big brake kits, sticky tires and ABS going into 10A, it is amazing how fast and controlled they slow down.


I'd like to hear more any ABS swaps you may have been a part of.

[silver69camaro]

I'd like to hear more any ABS swaps you may have been a part of.

Just one, although I've helped a couple others with their swaps.

In order to make it work properly, I had to do a huge amount of research...I know more about ABS than I ever thought I would. The results have been very positive so far, but I can't imagine doing it if you don't have the same access to info as I do.

[John Wright]

Would I be correct saying that the ABS would take away using the brake bias to help with balance issues during corner entry

adding more rear brake to free it up getting into the corner just a touch so you can get the car rotated...ect.

[HWYSTR]

Just one, although I've helped a couple others with their swaps.

In order to make it work properly, I had to do a huge amount of research...I know more about ABS than I ever thought I would. The results have been very positive so far, but I can't imagine doing it if you don't have the same access to info as I do.


What info do you have access to that would not be available to others? Curious, since I may now revisit this.

My thoughts initially were to look at the CTS-V setup, since the car weight and brakes are similar to mine. Again now, keep in mind, I'm working from memory from several years ago, so could be off on my thinking. But, my rational was that with the AFX spindles on a 68-72 A-body, using C5/6 brakes, the Caddy would be a logical choice. My thinking off silver69camaro?

-Mike

.

[XLexusTech]

see here

http://www.carcraft.com/eventcoverage/116_0602_1969_real_street_eliminator_amc_amx/index.html

[silver69camaro]

What info do you have access to that would not be available to others? Curious, since I may now revisit this.

.

I have contacts in General Motors and Ford, as well as other engineers in the field (Strange Engineering, Wilwood, couple vehicle manufacturers, etc). I actually had to get in contact with my old physics professor as well to sort out some magnetic flux problems I was having with the reluctors and wheel studs.

The AMX sounds like it has a similar setup as mine (although I use 4th-gen Camaro reluctors and sensors). If a 101-ft stopping distance doesn't convice people that ABS works well, I don't know what will.

[silver69camaro]

Would I be correct saying that the ABS would take away using the brake bias to help with balance issues during corner entry

adding more rear brake to free it up getting into the corner just a touch so you can get the car rotated...ect.

Yes, it would automatically change the proportioning.

But, weight transfer is weight transfer. You can always do it that way, instead of allowing the rear to skid.

[John Wright]

But, weight transfer is weight transfer. You can always do it that way, instead of allowing the rear to skid.ahhhh-OK, that makes sense.:)

[79PonchoUK]

Again, look at the purpose of a ABS system, which in theory is to aid an inexperienced driver in a panic situation to avoid loosing traction/control when braking. For an experienced driver, it does nothing but increase stopping/braking distances. Which is why F1 cars don't have ABS in my opinion.


.

F1 cars don't have ABS because they're not allowed to in the rules....like so many other reasons they do/don't do things.
If they were allowed to they'd have ABS simply to prevent flat spots under a lock up.

On a road car theres a very fine line between braking better than ABS and locking up. Technically, you can stop quicker without ABS, but it takes practice....and it depends on the ABS.


ABS isn't THAT complicated anyway...certainly not on the systems we'd be using. It isn't THAT dynamic either. It's a set of road speed sensors that when experiencing a mismatch of speed on the a wheel, stops and releases pedal pressure at a particular rate. The calibration is down to steering angles, wheel speed differences as a result of that, car length, tyre size and possibly a couple of other factors....if you have a system off a similar size car that steers with the front wheels, I'd suspect the system wouldn't need to be changed much at all.

The question is, is it easier to fit a system like that to the car, or spend a few days driving it - learning the pedal and grip somewhere out the way instead.

[wellis77]

I'd like to know what Prodigy is doing for ABS on Unfair. I haven't been through that entire thread in a while but I don't recall there being much discussion about it. I'd like to do ABS myself so I'm watching all this stuff pretty close.

...Just went back through the Unfair thread and Frank did talk about it and the fact they have to keep it quiet for now. I'm looking forward to the details when it comes out though.

[silver69camaro]

ABS isn't THAT complicated anyway...certainly not on the systems we'd be using. It isn't THAT dynamic either. It's a set of road speed sensors that when experiencing a mismatch of speed on the a wheel, stops and releases pedal pressure at a particular rate. The calibration is down to steering angles, wheel speed differences as a result of that, car length, tyre size and possibly a couple of other factors....if you have a system off a similar size car that steers with the front wheels, I'd suspect the system wouldn't need to be changed much at all.

That might be true for older ABS systems, but modern ones are very, very complicated. It's not just about bleeding pressure from a wheel that has zero RPM, it tries to prevent lockup too...that's where it gets complicated.

Take my car for instance. When the pads are cold, it doesn't stop all that great. Sometimes I can lock the wheels, sometimes I can't; don't get me wrong it still stops well, but not great. At this point, the computer is confused as to why pressure is so high but does not match the pressure versus deacceleration values it is programed with. As a result, it kinda freaks out a bit. It initially holds off pressure for way too long and is slow to cycle. It's still safe to drive around, but in this case the ABS is actually hurting the situation. And if you have 14" rotors on the street, the pads tend to be always cold.

Or, another instance. On of my master cylinders (rear) started leaking at the Del Mar Goodguys autocross (it's a balance bar system with two MCs). The computer saw the rear pressure was much lower than the front and, again, freaked out. It was constantly trying to reduce pressure to the front brakes and was actually pretty annoying. It will do the same if you have too much air in the lines as well.

All in all, it is complicated. Very complicated. It's easy to think it just reduces pressure when a wheel speed is zero, but that's just not the case. You could use an older pump and computer that is much simpler, but those don't cycle near as fast as a newer system and IMO wouldn't be worth the trouble.

Furthering this, I was doing some work on my ABS yesterday afternoon (reducing reluctor to sensor clearance for a better signal) and was doing some testing. With as hard as the car stops and how fast the brakes are cycling, it must really put stress on caliper brakets and such, not to mention the suspension itself. Because of this, if anyone is thinking about adding ABS, I would not do it with homemade brake brackets OR leaf springs. I can't imagine how violent the brake hop would be with leafs...the high speed loading and unloading would be pretty nasty. IMO anyway.

[BRIAN]

On one of the Porsche sites someone was attempting to adapt ABS to an older version 911 and had a link to a BOSCH? system that was generic. It was an aftermarket set up not for one specific car. A search might find it. I saw it on PELICAN in the 930 tech section.

[BRIAN]

I think this is the link?
http://www.bosch-motorsport.com/content/downloads/Documentation/ABS_M4_Brochure_en.pdf

[silver69camaro]

Yeah, we spoke to the head development guy for that and he was very adament about not using that for any type of street use. I have the instruction manual for it, and it's quite complex.

That and the near $8K cost kinda makes it tough to justify.

[Norm Peterson]

and he was very adament about not using that for any type of street use.
The little chart and the accompanying text (on page 2 of the link) makes it pretty clear why it isn't intended for street use.

Norm

[79PonchoUK]

That might be true for older ABS systems, but modern ones are very, very complicated. It's not just about bleeding pressure from a wheel that has zero RPM, it tries to prevent lockup too...that's where it gets complicated.

Take my car for instance. When the pads are cold, it doesn't stop all that great. Sometimes I can lock the wheels, sometimes I can't; don't get me wrong it still stops well, but not great. At this point, the computer is confused as to why pressure is so high but does not match the pressure versus deacceleration values it is programed with. As a result, it kinda freaks out a bit. It initially holds off pressure for way too long and is slow to cycle. It's still safe to drive around, but in this case the ABS is actually hurting the situation. And if you have 14" rotors on the street, the pads tend to be always cold.

Or, another instance. On of my master cylinders (rear) started leaking at the Del Mar Goodguys autocross (it's a balance bar system with two MCs). The computer saw the rear pressure was much lower than the front and, again, freaked out. It was constantly trying to reduce pressure to the front brakes and was actually pretty annoying. It will do the same if you have too much air in the lines as well.

All in all, it is complicated. Very complicated. It's easy to think it just reduces pressure when a wheel speed is zero, but that's just not the case. You could use an older pump and computer that is much simpler, but those don't cycle near as fast as a newer system and IMO wouldn't be worth the trouble.

Furthering this, I was doing some work on my ABS yesterday afternoon (reducing reluctor to sensor clearance for a better signal) and was doing some testing. With as hard as the car stops and how fast the brakes are cycling, it must really put stress on caliper brakets and such, not to mention the suspension itself. Because of this, if anyone is thinking about adding ABS, I would not do it with homemade brake brackets OR leaf springs. I can't imagine how violent the brake hop would be with leafs...the high speed loading and unloading would be pretty nasty. IMO anyway.


Oh, without a doubt, a modern system is much more complicated.


It's also integrated into a manufacturers powertrain management as a whole and as such isn't an option....unless you like to sit there spending 5 years of evenings pissing about with software, multiplexing and 7 different electronic modules.

I'm not sure it's fair to say the older one's aren't worth the trouble....as much to say that ABS isn't worth the trouble anyway.
The difference between the old ones and the new one's is certain, but not THAT huge in the grand scheme of things.

[Yoda4561]

The ABS system on the 2001 S10 we have would be the sort of thing I wouldn't mind on a pro touring car, if it were tuned a bit more agressive or something for sticky wide tires. The truck has rear leaf springs, and I haven't experienced any rear wheel hop issues, despite my aggressive braking habits and a number of panic stops. As it is it doesn't engage at all until the tires start to chip or slip noticeably while braking, seems to work well whether it's emergency stops on road or when getting run off the interstate onto a rough grassy median. And compared to what's been said about that "modern system" it's quite well behaved and predictable.

[MonzaRacer]

OK first of all if the tires are same size diameter within a specific tolerance your good.
After adapting a 3 channel system from the early Silverados have been very conducive to proper road manners without havign to jail break the controller.

The last car was an ATS spindle equipt, Silverado 10 bolt ,well drive line swapped in by luck we had the system up and running and he used Corvette sized rubber to keep it happy.
After nearly 2 yrs of it being driven,,,, no issues.

[silver69camaro]

OK first of all if the tires are same size diameter within a specific tolerance your good.

My experience hasn't been so easy. Perhaps because I'm using stability control as well?

[79PonchoUK]

Just cut a big chunk out of the rotor with an angle grinder....it'll feel like abs...what more do you want?

[64Chevelle]

What about this system:

http://www.southwestspeed.com/?sec=view_part&id=1202

I haven't taken the time to read about it yet, but it might be worth taking a look at.

[wellis77]

What about this system:

http://www.southwestspeed.com/?sec=view_part&id=1202

I haven't taken the time to read about it yet, but it might be worth taking a look at.

I'm still digging into this one, but it seems they are not supposed to be calling it an ABS.

http://www.ftc.gov/opa/1998/01/brake.shtm

Here is there website.
http://www.brake-guard.com/index.html

[Norm Peterson]

It's nothing more than a hydraulic accumulator, which will do what they say it'll do - reduce pressure spikes slightly.

Problem being, nobody uses the brakes such that pressure spikes are created, other than the initial application in a hard stop.

At best, it's a band-aid for levels of rotor runout, thickness variation, or unevenness of pad deposit that you maybe shouldn't be driving with.


The periodic pressure fluctuations result from a warped rotor we purposely placed in the system to simulate a badly worn rotor.
The graph does not make the results look all that impressive.
http://seniordesign.engr.uidaho.edu/1998_1999/simustop/page5.html

I think that years ago this same product or something extremely similar was sold as the "Safety Breaker" or some such name.


Norm

[64Chevelle]

Thanks for that link. Seems it's primarily for larger vehicles

[wellis77]

For some reason I had always thought that ABS had to do with vehicle weight as well as tire/rotor/caliper size. From the research I've done, it seems the algorithms are based on the tire size, as well as the caliper, pad, and rotor. So when considering adapting an oem ABS to our cars, if we match these components we should be fine.

I also understand this from Lee's post:

OK first of all if the tires are same size diameter within a specific tolerance your good.
After adapting a 3 channel system from the early Silverados have been very conducive to proper road manners without havign to jail break the controller.

The last car was an ATS spindle equipt, Silverado 10 bolt ,well drive line swapped in by luck we had the system up and running and he used Corvette sized rubber to keep it happy.
After nearly 2 yrs of it being driven,,,, no issues.

"If" this is correct, with me using all Viper components (wheels/tires, calipers, rotors, even booster/m.c.), I shouldn't have any problem at all adapting Viper ABS to my project.

Please correct me if my understanding is off base.

Another thought, can the ABS controller be wired to a switch in order to turn it off? Not that I would necessarily do it, but if it's wired to a switch and turned off, brake fluid should flow through as if there were no ABS?

This is a great thread...

[Norm Peterson]

Another thought, can the ABS controller be wired to a switch in order to turn it off? Not that I would necessarily do it, but if it's wired to a switch and turned off, brake fluid should flow through as if there were no ABS?
That should work. Even putting a switch in line with any one of the sensors should be enough to take the ABS offline and revert everything back to purely hydraulic operation.

My '01 Maxima has an 'open' wheel sensor that amounts to the same thing as having a sensor wire switch turned 'off', and the car stops very nicely. Its continued good braking performance and since it actually passed inspection with the ABS lamp lit, Nissan isn't going to get $150 from me for a new sensor (that's the part price only).


Norm

[silver69camaro]

For Bosch ABS systems, you can wire a switch inline with the brake lamp switch. When the brake lights turn on, it puts the EBCM in "ready mode", and alerts it to be prepared for action.

If you keep the braking system (and tire diameters) close to stock, it should work OK. If you start mixing calipers, the pressure-to-deacceleration wont match the EBCM's calibration, and could cause problems and go into limp-mode.

Going back to switching ABS on and off, keep in mind that all newer cars have the EBCM do the brake pressure proportioning. So, if you were to switch it off, it would resort to 50/50 distribution in brake pressure, which will cause the rears to lock up very easily.

[wellis77]

Thank you Norm and Matt for answering those questions for me. I appreciate your insight. I won't run a switch to turn the ABS off, but wasn't sure and thought I read something about people doing that. Great information, thanks again.

[Wicked]

I've worked for Honda as a brake/VSA/ABS "expert" for 8 years. If you were talking about VSA(stability system), there would be substantial difficulty.
But as someone said above, ABS is pretty simple. You could adapt a modulator from most any newer car(preferably a pre-CAN system).

On our Hondas Odyssey race minivan, we have a gutted vehicle that weighs 1000lbs less than stock, road race suspension, and the ABS works just fine.

ABS works on wheel speed comparison. If a wheel loses traction, the ABS will unlock it.

On our systems, power, ground, and 4 wheel speeds signals is all it take to run the ABS.

[Wicked]

My bad, you also need a brake light switch to signal a braking condition.

[ace_xp2]

Hey Wicked, you wouldn't be able to point out a specific year/model Honda which had so simple a system would you? Seems like a great way to get basic ABS going.

[Norm Peterson]

I've worked for Honda as a brake/VSA/ABS "expert" for 8 years. If you were talking about VSA(stability system), there would be substantial difficulty.
But as someone said above, ABS is pretty simple. You could adapt a modulator from most any newer car(preferably a pre-CAN system).

On our Hondas Odyssey race minivan, we have a gutted vehicle that weighs 1000lbs less than stock, road race suspension, and the ABS works just fine.
How much of the programming was based on some assumed mu-slip curve, and what general kind of tires were assumed for that lookup?

I'm told that you don't want to be operating on the back side of that curve, at least not for acceleration vs wheel hop.


Norm

[MonzaRacer]

THe reason for us using the GM truck set up is that in the 3k to 4 k weight range the truck system works fine.
Reason for using it was economics as well as the info I had already dug up.
In all honesty the Delco and KH setups seem to work better than any Bosch related "stock" setup.
The C/K truck set up worked well in a 3 channel setup. and in a live rear axle set up it worked well.
I also am thinking of installing ABS on my 84 Caprice, after I install the bbc and turbos.

[Scott Parkhurst]

I also am thinking of installing ABS on my 84 Caprice, after I install the bbc and turbos.

Any estimate on what year that'll be?

[Wicked]

Well, lets try this a second time...lost my first attempt at a response.

Norm,
My particular experience regarding involves a highly modified Honda Odyssey(I work for Honda) which we competed in the One Lap of America with 3 years in a row. Tires were changed from 235/60/16 all-season to 275/35/19 Pilot sport II's. The suspension was upgraded with H&R coilover and rear springs and adjustable dampers. Springs rates were 4X in front and 2X in rear. Weight dropped from 4500lbs to 3500lbs. And it made 532whp from a turbocharged 3.5 V6. Now, the VSA(stability control) was WAY OFF at this point due to all the changes. But the ABS works just fine. The system does calculate vehicle reference speed and estimate mu based on tire slip conditions using the wheel speed inputs.

Now as to what system works best, hard to say for sure. Some trial and error could be involved. The key issue is getting wheel speed sensors and encoders setup. Our systems used dipoled bearing seals. Some units have 46 pairs of north/south poles.

[MonzaRacer]

Any estimate on what year that'll be?

Well the ABS should be a basic upgrade, Im looking at a totaled 96 Impalla SS/Caprice, not sure which it is its so beat up, but hey cut roof off and drove it up on flatbed. Engine/trans are no gone. But dealing on rest of it. so the Caprice is a basic bolt in. Well except the big block with turbos.:)
The Monza is a little more difficult unless I can source enough of a ZQ8 Blazer or get a set of ATS spindles and source a ZQ8 rearend.
Time money and economy will tell. If taxes work out the home is paid off 6 months early, this opens up some extra cash for car fun!
Im still trying to deal on T56 from a Firebird and use that in the Monza but lost my pedals when I junked my old yellow one, so I gotta source or make new ones, making may be the best option. My big issue is dialing in the tire size difference on the Monza.
The Caprice is gonna be easy as I will be running Corvette size rubber.
Considering 2 years ago next week I was back on street looking or well waiting for a job, I think my plans are going MUCH better. And my side business is starting to come around.

[64skylarkls1]

Not trying to hijack a thread but isn't it possible to use a complete ABS system from an LS1 car into an A body? I'm doing the complete motor tranny and harness swap right now. Condsidering my options. Thanks.

[Scott Parkhurst]

Sure - it's possible. It's a commitment to same-size tires as the OEM specified, and it may not be 'perfect' as weights will not be identical to OEM, but if you do a wholesale swapover, it should function just fine.

[64skylarkls1]

If that's the case, I have a few questions. Does someone make sensored spindles that would adapt to the factory harness? Also I would need to use the '02 camaro rear axle as well?

[CamaroAJ]

If that's the case, I have a few questions. Does someone make sensored spindles that would adapt to the factory harness? Also I would need to use the '02 camaro rear axle as well?

the aftermarket has the speed sensors in the housings in pretty much any set up you want. i am building my '69 with a 4 channel set up from an '01 camaro, each axle has the reluctor rings pressed on them already. and i have ATS front spindles. if it doesn't work i'll get a corvette ebcm/bpmv and pig tail and repin to match my car.

[64skylarkls1]

Really, can you point me to some of the aftermarket suppliers that offer ABS conversion parts. I've not come across them. I won't go with ABS if I have to purchase nearly the whole system. Like you, I am adapting from an '02 Camaro to my A body.

Thanks again.

[CamaroAJ]

don't know if anyone sells conversion parts or not. moser and currie sell a 12 bolt and 9" with 3 and 4 channel ABS for 4th gen f bodys. if you are using 4 channel then you can get different axles. you might have to narrow the housing depending on your wheels.

i'm sure there is a way to make a 3 channel work though. you could probably just use the speed sensor on the transmission.

[silver69camaro]

Nobody sells a conversion kit that I know of either. I just adapted F-body 4-channel reluctor wheels to my current axles, and they have the same tooth count has a C5/C6 hub. Packaging the rear sensor within the parking brake mechanism is a pain though, and fine-tuning the sensor/reluctor clearance isn't fun either (especially if you have thread-in wheel studs).

[64skylarkls1]

Sounds like a little more work and complexity than I want to go through, kudo's to those who can. Thanks for the insight.

[wellis77]

Seems like a great opportunity for the aftermarket to develop something in a programmable 2 or 4 channel system where logarithms are pre-programmed, you input wheel/tire size, and whatever other parameter's are necessary, and the system is good to go;its to mount sensors/reluctors to various applications. There would be some legal stuff to work through to avoid liability, off-road only?, but seems like it should be able to be worked out. With as much as we spend on brake kits these days, I would bet if a package could be built and pieced together for 1-2k it would sell.

Just thinking with my keyboard...

[silver69camaro]

Will, I can see that happening. I would imagine a basic aftermarket system would work only on notice of lockup, instead of predicting when it might occor like some OEMs do. The current programmable system out there today is way too much $$ for people, but frankly, most car guys think ABS is for wimps.

But, I think anytime you sell a device that can cut brake pressure electronically, you're setting yourself up for some real liability issues. Even though parts are listed for "off-road use only", companies still get sued.

[EFI69Cam]

Did you have to match your tire sizes to the orgininal application your abs module came from? With the tech2 I was able to change tire size for the ABS system on my 2003 Suburban when I changed the tire size. Is this option available on the Corvette ABS?

[wellis77]

But, I think anytime you sell a device that can cut brake pressure electronically, you're setting yourself up for some real liability issues. Even though parts are listed for "off-road use only", companies still get sued.

I'm sure you are right on this. It's just too bad since there seems to be a small but growing demand, especially now that builders are getting into the adapting ABS mix. That's what got me thinking it and I'm all about putting as much safety as I realistically can into my build.

[silver69camaro]

Did you have to match your tire sizes to the orgininal application your abs module came from? With the tech2 I was able to change tire size for the ABS system on my 2003 Suburban when I changed the tire size. Is this option available on the Corvette ABS?

I didn't have to, but the ones I came up with are pretty close. I was told you have a decent margin of error to work with. As far as using the Tech2, I don't know. I tried real hard to find somebody to use it on my setup and nobody wanted anything to do with it! Oh well.

[CamaroAJ]

you cannot change tire size with the tech 2 on corvette's or 4th gen f-body's. you can't even use the tech 2 on the new camaros.

[DarkoNova]

Nobody sells a conversion kit that I know of either. I just adapted F-body 4-channel reluctor wheels to my current axles, and they have the same tooth count has a C5/C6 hub. Packaging the rear sensor within the parking brake mechanism is a pain though, and fine-tuning the sensor/reluctor clearance isn't fun either (especially if you have thread-in wheel studs).

So wait, are the reluctor wheels easily mounted to non-oem axles? Or was there some custom work involved? I just spent a ton of money rebuilding my 8.5" 10 bolt, and it'd be nice to be able to just add reluctor wheels to it, instead of having to buy an entirely new rearend.


you cannot change tire size with the tech 2 on corvette's or 4th gen f-body's. you can't even use the tech 2 on the new camaros.

What about aftermarket tuners?

[silver69camaro]

Well, it's not too bad to adapt the wheel to an axle, you have to make an adapter that presses onto the axle that holds the wheel. I don't know how you'd do it on a 10-bolt, since all I use are 9" axles. But, Chevs have a larger axle flange offset, which makes more room for the wheel, sensor, and P-brake hardware. The space is critical because the sensor can pick up the teeth on the reluctor wheel AND the wheel bolt heads. The faster the axle spins, it seems the magnetic flux field grows and the sensor starts to "see" other moving metal objects. I only had problems above 70MPH (the EBCM would go into traction control mode due to a messed up signal), but I managed to fix that. Took about a year, though.

[EFI69Cam]

Moser will install reluctors on their axles, I talked to them about it and I seem to recall it was $150, with me supplying the reluctors.

Matt, too bad you're in WA, I have a tech 2 and would have no problem hooking it up.

CamaraAJ I thought the Tech 2 works on newer CAN bus GMs as long as you have the appropriate adaptor (CANdi module) dealer here said about $600.

[CamaroAJ]

CamaraAJ I thought the Tech 2 works on newer CAN bus GMs as long as you have the appropriate adaptor (CANdi module) dealer here said about $600.

yes it does. the new camaro and the new equinox systems do not support the tech 2 or candi module. it will interface with the mdi and a laptop.

DarkoNova, no aftermarket has the ability to change wheel size in the ebcm.

[vintageracer]

Didn't Steilow have ABS on the new Red Camaro?

You cannot tell me that did not provide an advantage over other competitors in the Start/Stop and road course who were not ABS equipped.

Technology is a wonderful thing!

[64skylarkls1]

Nobody sells a conversion kit that I know of either. I just adapted F-body 4-channel reluctor wheels to my current axles, and they have the same tooth count has a C5/C6 hub. Packaging the rear sensor within the parking brake mechanism is a pain though, and fine-tuning the sensor/reluctor clearance isn't fun either (especially if you have thread-in wheel studs).

I'm curious what you went with for a rear axle and brakes. I was hoping to get a big brake kit to fit the fbody '02 camaro rear and then actually have a 9" made the accept the whole works from the Camaro rear but the package is 1750 just for the rear brakes. Plan B is to do something similar to what you've done, get a 9" made with the reluctors on the axles and build my own sensor mount set up. There isn't anyone that builds them complete this way right?

So, if I go that route, then my concerns become what someone else had mentioned - will it make a difference which front and rear calipers I go with? I plan on using AFX spindles up front to stay with the four channel and 13" brakes all around. With the added space needed for the reluctors on the rear axles, what brake package would bolt up and still allow room to mount the sensor? Does it need to be a brake package that is matched together front and rear for proper fluid distribution from the stock F-body ABS unit?

[silver69camaro]

I have a Ford 9" style axle with Wilwood 13" brakes w/ internal parking brake drum (which is a knock-off of the Explorer parking brake, which also uses a similar reluctor/sensor setup as an F-body).

You can buy the axles with reluctors, but you'll probably have to press them on yourself. If you go with all stock parts, you shouldn't have any clearance or signal issues like I did (had to figure everything out myself...). As far as straying from the OE brakes, just buy something with similar piston areas as the OE calipers. According to my research it does make a difference, although some swear it doesn't. I know of some people who have tried it without considering the OE fluid volumes and ended up not being happy with the way it worked, while I did my best to adhere to those rules and it worked out wonderfully.

[64skylarkls1]

Thanks for your input but I was hoping for a cheaper route. If I'm right, the Wilwood set up you're talking about is the one that will fit the F-body application but is a bit pricey for me at 1750 just for the rears.

Seeing as I'm building a daily driver with no intent on road course racing, for now I probably stick with the stock F-body brakes front and rear with the plan of upgrading down the road. That way I can get full use of the ABS, cruise and everything else that the Camaro donor has to offers yet keep the build costs down. Besides, it will aid in trouble shooting the ABS if all the components are stock such as caliper ratios front to rear.

What I will purchase then is ATS spindles and have a custom 9" built with the reluctor rings and axle/housing geometry similar to the f-body axle.

Am I missing anything? Should work right? I would be interested in comments from all. Thanks.

[Bjkadron]

So Matt, Where can I get information on piston sizes and weight distribution for various cars so I can find the right donor? Also, aren't most ABS systems in the main ecu/everything box? or is their a different controler somewhere?

[silver69camaro]

The EBCM is normally attached to the pump on Bosch systems, so no PCM is necessary. For piston sizes, I'm not sure what the best public source is...somebody else here might know.

[silver69camaro]

Thanks for your input but I was hoping for a cheaper route. If I'm right, the Wilwood set up you're talking about is the one that will fit the F-body application but is a bit pricey for me at 1750 just for the rears.

Seeing as I'm building a daily driver with no intent on road course racing, for now I probably stick with the stock F-body brakes front and rear with the plan of upgrading down the road. That way I can get full use of the ABS, cruise and everything else that the Camaro donor has to offers yet keep the build costs down. Besides, it will aid in trouble shooting the ABS if all the components are stock such as caliper ratios front to rear.

What I will purchase then is ATS spindles and have a custom 9" built with the reluctor rings and axle/housing geometry similar to the f-body axle.

Am I missing anything? Should work right? I would be interested in comments from all. Thanks.

Sounds good to me, I think that would probably be the cheapest way to go. Cost-wise, the whole thing isn't that cheap. Plan on a couple hundred for the EBCM/pump, probably $100-200 on wiring and connectors (and you do have the crimping tools, right?), and another $150 or so for sensors and related stuff. So if a person spent $600 on the whole deal I wouldn't be too surprised.

[64skylarkls1]

Sounds good to me, I think that would probably be the cheapest way to go. Cost-wise, the whole thing isn't that cheap. Plan on a couple hundred for the EBCM/pump, probably $100-200 on wiring and connectors (and you do have the crimping tools, right?), and another $150 or so for sensors and related stuff. So if a person spent $600 on the whole deal I wouldn't be too surprised.


Actually, I have everything from the donor car so I shouldn't need any of that. I already installed the Camaro column and pedal set up to maintain all the factory wiring. The only problem I just came across was that the AFX spindles supposedly won't fit the F-body brakes. I may need to go with the C5 set up. I will need to look into the possible piston size difference between the f-body and the C5 on the front or consider making my own mounting brackets for the F-body front brakes.

[CamaroAJ]

Actually, I have everything from the donor car so I shouldn't need any of that. I already installed the Camaro column and pedal set up to maintain all the factory wiring. The only problem I just came across was that the AFX spindles supposedly won't fit the F-body brakes. I may need to go with the C5 set up. I will need to look into the possible piston size difference between the f-body and the C5 on the front or consider making my own mounting brackets for the F-body front brakes.

f body calipers will bolt to C5 arberment brackets. use C5 rotors and pads. C5 pistons are smaller that f body pistons by like .3mm if i remember right.

also you will need to change the pigtail end on the front harness because the connector is different on a f body than the corvette hub. i have mine all wired up already from my donor '01 SS with traction control.

[64skylarkls1]

f body calipers will bolt to C5 arberment brackets. use C5 rotors and pads. C5 pistons are smaller that f body pistons by like .3mm if i remember right.

also you will need to change the pigtail end on the front harness because the connector is different on a f body than the corvette hub. i have mine all wired up already from my donor '01 SS with traction control.

Man, what a wealth of info on this site! Are the C5 rotors different than the 12" f body rotors? Thanks to all!! :worship:

[CamaroAJ]

Man, what a wealth of info on this site! Are the C5 rotors different than the 12" f body rotors? Thanks to all!! :worship:

yes, the offset is different anyways.

i looked it up again. f body caliper pistons are 44 mm, where as the C5 piston size is only 40.5mm. Because the C5 rotor is 13" the caliper has more leverage and thus doesn't need pistons are large.

[protour73]

Didn't Steilow have ABS on the new Red Camaro?

You cannot tell me that did not provide an advantage over other competitors in the Start/Stop and road course who were not ABS equipped.

Technology is a wonderful thing!

Yes, Mark does have ABS on the Red Car. It is documented somewhat in the build thread for that car. He is presently having problems with the system freaking out at 120mph. THAT has to be exciting!!! If I understood what he said in the CHAT the other night, he said he is working on developing an ABS kit.

[TnMonteSS]

Didn't Steilow have ABS on the new Red Camaro?

You cannot tell me that did not provide an advantage over other competitors in the Start/Stop and road course who were not ABS equipped.

I suspect many/all of the 2011 competitors to OUSCI will be sporting ABS systems....

I was pulling for Brian Finch. He won many of the qualifiers, but I saw a picture of his Camaro prependicular in the Speed/Stop stop box at Holley LS Fest, and I see he took 0 points at the Speed/Stop event at Pahrump, and still finished 6th overall.....Brian, is ABS in your future??

[Bjkadron]

The EBCM is normally attached to the pump on Bosch systems, so no PCM is necessary. For piston sizes, I'm not sure what the best public source is...somebody else here might know.

So how do you find out who uses Bosch and who uses KH and others? Well I'm using Dodge Viper calipers on the front, and something similar on the back, with similar weight distribution, But I was kinda hoping for a cheaper donor... Thanks for the advice though ABS systems aren't something that I've spent a lot of time looking at when I take cars apart..

[64skylarkls1]

For adapting the LS1 ABS I started a new thread. This thread is more about ABS in general and I didn't want to impose on it anymore. I have a few more questions on that thread and would appreciate any and all insight. The new thread is "ABS from LS1 - it's all in the details"

Thanks again.

[DoABarrelRoll]

http://www.southwestspeed.com/?sec=view_part&id=1202


Did we talk about this part yet?

[Norm Peterson]

It has nothing to do with current ABS systems and appears to be little more than a hydraulic accumulator (sort of a high pressure micro-Accusump). Versions under different names have been around for quite a long time. I suppose it would help non-ABS brake performance a tiny bit if you could stomp on the brake pedal hard enough to make the accumulator fill and by doing so take a little of the abruptness out of the actual initial brake "grab". I *think* it's targeted toward the lowest-common-denominator sort of driver who treats all the vehicle controls like off/on switches.


Norm

[hectore3]

http://www.southwestspeed.com/?sec=view_part&id=1202


Did we talk about this part yet?

Sounds like "snake oil". I have the ATS corvette spindles and would love an off the shelf solution. But it seems liability is keeping potential manufacturers from coming off the fence to supply us.

[Stielow]

Didn't Steilow have ABS on the new Red Camaro?

You cannot tell me that did not provide an advantage over other competitors in the Start/Stop and road course who were not ABS equipped.

Technology is a wonderful thing!

Yes I have a C-6 Delphi ABS ECBM on Red Devil. I have a similar problem to Matt's that my rear wheel sensor drop out at high speeds. It worked great for AutoX and the Speed Stop Deal at Optima. If things work out I may have a fix for the erratic rear wheel speed sensor for 2011. I have parts at the machine shop now.

When my ABS worked at the road couse stuff it was awsome. When it faulted out it sucked and flat spotted a lot of tires.

I also have about a year and a ton of time tring to get my ABS system to work flawless.

Mark

[vintageracer]

Mark,

Thanks for the reply. It appeared to me the car had ABS when we were both at the LS Fest in BG running the autocross and watching the start/stop. Just the next logical progression in top shelf PT cars. Thanks for continually raising the bar in the hobby.

Congratulations on the Optima victory!

[silver69camaro]

I have a similar problem to Matt's that my rear wheel sensor drop out at high speeds.

Did you figure out a reason why? To me, it appears the sensor starts to pick up the wheel bolt heads in my case; perhaps the magnetic flux field grows while rotating speeds increase causing erratic sensor readings. I have a solution to the problem and based off of our conversation we're on the same path.

[Norm Peterson]

Maybe it's not that the flux field can grow, but that whatever disturbances in that field that the bolt heads cause will pass the sensor in a shorter amount of time. Perhaps this could be enough to go from background noise to become a pulse strong enough to be "counted"??? It seems that time is involved in this stuff.

http://en.wikipedia.org/wiki/Magnetic_flux

http://en.wikipedia.org/wiki/Magnetic_field


Norm

[Stielow]

Did you figure out a reason why? To me, it appears the sensor starts to pick up the wheel bolt heads in my case; perhaps the magnetic flux field grows while rotating speeds increase causing erratic sensor readings. I have a solution to the problem and based off of our conversation we're on the same path.

The opinion of experts varies as to why my rear wheels speed sensor drop out. Too big of a gap to small of a gap.... So I'm going to an integral wheel speed sensor that should fix that problem. An intermittent ABS system is a pain on high speed tracks when you want to rely on it. I knew my car would fault at Optima so when I locked a tire in turn one, I had a redundant prop valve in the system that let the car work like it had no ABS.

Mark

[Wicked]

Mark,
Are you using the encoders/tone wheels for that exact system? Also, you mentioned gap...is the gap within spec for the C6?

[FlyDoc]

Sounds like "snake oil". I have the ATS corvette spindles and would love an off the shelf solution. But it seems liability is keeping potential manufacturers from coming off the fence to supply us.

this product takes out the fluid shock of slamming the breaks. not an ABS "system" that we are looking for.

I don't think that we will ever see an after market ABS system because of the liability.
as we retro fit OEM systems to our cars we remove the liability from the manufacture. why do you think that OEM ABS systems are built & designed by a different company that builds the car.

[dhutton]

Would be great if someone could solve all the issues and introduce a kit.

[andrewb70]

Any updates?

Andrew

[tlillard23]

My experience hasn't been so easy. Perhaps because I'm using stability control as well?

STABILITY CONTROL!!! AND YOUR HAVING PROBLEMS???? LOL! No kidding... Now I see why you are poopooing everyone that wants to use ABS. Interesting that you are trying it, but stop with the "you can't do ABS 'cause your car weighs more". You are an engineer, ABS does not equal stability control. If all 4 wheels are ~the same diameter, the abs will work fine. there is a chance that weird conditions will cause the ABS ICE-MODE to kick in, primarily a crappy driver and or different amounts of traction on each wheel. ICE-MODE give the car 1/10th (G?) braking power, it's waaaaay sucky. happened a number of times when I started autocrossing

Everyone is talking about f body rear ends... WHICH ONE?? the 3 sensor system or the 4 sensor system? and which one of those will work with the ATS/corvette spindles? I THINK the f-body 3 sensor is the non-traction control-switch-having model, the 4 sensor is the traction-control-switch-having model. Because ALL of the V8 f-body (4th gen? 97-2002?) cars have ABS/traction control - just some of the cars had a (traction control) switch to shut it off. Will ATS work with both 3/4 systems?

Now my question: what does the 2005 GTO have? What rear do I need, 3 or 4 sensor system? and does it use the same reluctors as Fbody/corvette

Flame ON!

[ace_xp2]

Just something to add to the thread here now that I see this popping up again.
Has anyone thought about doing pwm conversion? Most of these systems seem to be based on pulse width readings off the abs sensors. Rather than the difficulties involved in getting a completely matching set, why not convert the signal to whatever the brake ecu happens to need? There's got to be gpio style boards which are at least as reliable as the braking ecu.

[Norm Peterson]

You are an engineer, ABS does not equal stability control.
Don't overlook the fact that an OE ABS system must first "do no harm", so its tuning and calibration isn't going to be quite as simple as looking at one individual wheel and either braking or releasing it. Split-mu surfaces is one circumstance where a simple ABS logic can put you in no better of a situation than not having it at all.

I think I read earlier in this thread about the unavailability of systems for which you could do your own tuning, but I don't have enough battery left to find it for you.


Never mind that there are still times where current OE ABS systems can get a bit confused.


Norm

[silver69camaro]

STABILITY CONTROL!!! AND YOUR HAVING PROBLEMS???? LOL! No kidding... Now I see why you are poopooing everyone that wants to use ABS. Interesting that you are trying it, but stop with the "you can't do ABS 'cause your car weighs more". You are an engineer, ABS does not equal stability control. If all 4 wheels are ~the same diameter, the abs will work fine. there is a chance that weird conditions will cause the ABS ICE-MODE to kick in, primarily a crappy driver and or different amounts of traction on each wheel. ICE-MODE give the car 1/10th (G?) braking power, it's waaaaay sucky. happened a number of times when I started autocrossing

Everyone is talking about f body rear ends... WHICH ONE?? the 3 sensor system or the 4 sensor system? and which one of those will work with the ATS/corvette spindles? I THINK the f-body 3 sensor is the non-traction control-switch-having model, the 4 sensor is the traction-control-switch-having model. Because ALL of the V8 f-body (4th gen? 97-2002?) cars have ABS/traction control - just some of the cars had a (traction control) switch to shut it off. Will ATS work with both 3/4 systems?

Now my question: what does the 2005 GTO have? What rear do I need, 3 or 4 sensor system? and does it use the same reluctors as Fbody/corvette

Flame ON!

Sounds like you know everything there is to know...

[flyvmo]

Good morning everyone, and my apologies for resurrecting an old thread.
I just joined your forum after I stumbled upon it, and this thread in particular. I have been researching for months now the possibility and requirements to retrofit an ABS system from a 2002 Corvette Z06 into my Porsche 928 (1990 model).
My car is getting an LS3 swap and GM 6-speed transmission, and is currently getting the ISIS multiplexing electrical system installed. It is featured here: http://infinitybox.com/2014/08/11/project-update-1990-porsche-928-gt/

I stumbled across an article in hotrod magazine about some one doing this swap into their '69 Camaro, and I had a question regarding the reluctor teeth requirements. My car has 45-tooth reluctors but I think the Z06 uses 47 teeth. Will the difference in tooth count confuse the system?
My current system is an old mid-80's Bosch ABS that no longer works and instead of spending ridiculous amounts of money on used Porsche parts I wanted to install a modern 4-channel system instead and possibly utilize the stability control as well. Do I need to change the ABS reluctor wheels or will the system handle them? Thank you so much for any advise you may have.

Cheers!
Carl

[tlillard23]

Finally got abs tcs working on my 66 gto. I used the 05 GTO ABS controller, I wouldn't do that again, rear wheel tone rings from a 2002 Camaro, front ats spindles with Corvette hubs with built-in sensorss. you could go with a Corvette ABS module and do a stand-alone unit. don't get an ABS module with electronic brake bias(like the gto). because when the module fails or you need to pull the fuse to meet the rules (such as the new CAM rules) the brake bias defaults to almost no rear brakes

And silver69 Matt, nice post, extremely !helpful