drop spindles on 2nd gen camaro

[graycamaro]

what effects would a drop spindle have on a 2nd gen f bodys handeling abilities?

thanks

[79T/Aman]

increased scrub radius.

[JoshStratton]

When you say 'increased scrub radius' do you mean it is positive or negative? This is something I too am trying to understand. I am putting Baer disks with 2 inch dropped spindles on my car and also wonder about the effect. I realize they will push the wheels out about 1/2 inch from where they were originally, and the backspace will have to be adjusted to bring the scrub back to where it should be...as well as make sure they fit under the fenders properly, but what are the performance and safety effects?

EDIT:
NEVERMIND. Later in this post we find the Baers will work fine, for anyone who cares.

[Boyd]

Anyone? I'd like to know also....(man, there just isn't too much interest in us 2nd Gen guys is there?)

[hotrod]

Hi Boyd, I'll jump in here as well since this is something I plan on doing, increased scrub radius or not. Kuhlryde, I didn't realize that the dropped spindles would widen the track. Is it those spindles or Baers package itself whether it's dropped or not. Also is it 1/2" per side or 1/2" total?

[JoshStratton]

I am not sure, actually. I have a 79 with the Baers. They deliver them on the dropped spindles and I was told they would push the wheels out .5 inches so your rims would have to be adjusted to account for it. I am not sure if it is all of them or just the Baers that do it. I will PM Yody to get in on this. He really seems to know these cars well. So does Aman. Maybe one of them will join in...

[Mean 69]

I'll have to look at the spindles in my shop again, but I "think" that a dropped pin would actually improve scrub radius? Not trying to start anything, but I thought that the KAI was pretty upright, so it would have a pretty stout static scrub radius, so I think that dropping the pin would actually help things in this aspect.

One thing for certain, the pin is extremely low on the spindle on the second gen's, so lowering the car would probably put the lower control arm into a less than desireable angle, my guess is that the geometry would get even uglier. Quick. At first glance, and this is only a casual observation, I'd think a dropped spindle might be a good way to lower the car, but I hope someone with more specific info will chime in. For certain, just like the first gen Camaro's for performance, you'll need to start with a whole bunch of static negative camber.

Mark

[hotrod]

Mark, most everything you say makes sense. I don't know if you're familiar with the VBP monoleaf front suspension but that is what I have and in order to get the ride height down there I have had to adjust the bolt as far as it will go and the camber is hard to get to go negative. With 2" dropped spindles I hope to get the ride height where I want it and get the lower arm back to the correct angle. Hey Boyd and Kuhlryde pics are in my garage.

[JoshStratton]

Yikes. I wish I knew more about suspension geometry.

First, forgive me, I am a newb to suspensions....

Ok. Let me ask this. I have been following Yody's suspension and he has a pretty nice setup and I am actually thinking of matching his....among other options. Any thoughts on how this setup will interact with the dropped spindles? Mark's comment about the drop affecting the lower control arm worries me.

Will I need to adjust the suspension for a new lower control arm? If not, what can I do to get the camber back to where it should be?

Front
•Baers with 2 inch dropped spindle
•Global West del-a-lum bushings for lower control arms
•SPeedtech tubular upper control arms
•Hothckis 1 3/8 hollow front sway
•Bilsteins
•Hothckis small block coils

Rear
•Hotchkis 3-leaf
•No rear sway
•Bilsteins

[yody]

Actually Mark, I could be totally off here but if you raise the spindle up, then wouldn't the scrub radius increase? because you are raising the wheel up but teh control arm and ball joint angles stay the same, so wouldn't the space between the wheel centerline and the balljoint line increase?also if the KAI is upright wouldn't that make the scrub radius really bad???

I have no idea why Baer brakes kit would increase the track 1/2" on each side. that is HUGE. THe rotor itself is only like 3/16" thick, so if their hub had the same spacing as a stock rotor assembly the wheel would only stick out the thickenss of the rotor hat. Seems baers setup is all screwy, you would think they would design a hub that woudl keept the stock backspacing?? Most second gen guys run about 4.5" backspacing on a 8" wheel.

Edit,
not sure how far you want to drop the car, also not sure why you would need new lower control arms? If you really want to slam the car, the drop spindles would be a good thing. When I initially cut my springs too much and i had that killer stance, the lower control arms were about 5/8" away from the frame, and i couldn't even get a bump stop in there, the top of the lower control arm would of hit the frame! So a drop spindle is "probably" a good thing. You might be too low with the drop springs too. But you won't know until you assemble it all.
BTW I think the static camber has to do with your alighment settings, there isn't much you can do about camber gain with the stock suspension throughout the suspension travel.

[JoshStratton]

Ahh. So you would suggest running that setup but with stock height springs instead?

I dont really want to slam the car. I am trying to acheive that balance of comfort and strong support

DISCLAIMER: I cannot remember if it was Baer that told me that or someone else. I just remember being told somewhere that the Baer spindles would push the wheels out. Its great if they dont. I really hope they dont, but there arent too many guys running Baers on their 2nd Gens...so it is kind of hard to verify.

[yody]

Well I would verify it before i bought any new wheels. I can't really say about whether using drop or standard hegiht springs. It really all depends on how low you want the car, and what is under the hood. I personally depending on low you want the car and how heavy the front end is, probably use the hothckis springs first, you can always sell them if its too low. Your currente suspension setup is pretty much identical to mine and should work pretty good, it won't be a race car by any means but should handle its own no problem. I too don't have much info on the drop spindles, but if mark thinks its a good idea to raise the spindle pin height, than it could be a good idea.

The scrub radius is like this,
first draw a line down the centerline of the wheel, straight down the middle of it(viewing from the front of the car)
then draw a line from the center of the upper ball joint to the center of the lower ball joint, then follow the line until it intersects with the line you drew down the centerline of the wheel. The distance between the 2 lines at the ground(bascially bottom of wheel) is the scrub radius, making this distance bigger is bad because it gives less feeling/feedback to the steering, and making it smaller gives better steering feedback................I think :) raising the spindle pin UP which is how you lower the car wiht a dropped spindle "should" make the distance greater.

[JoshStratton]

Are there any ways of adjusting that distance if I were to still use the spindles?

[yody]

space your wheels farther inboard, which i wouldn't do. Not sure how bad the drop spindle will affect the scrub radius, it might not be a big deal, if your not trying to drop the car too much you just be fine with regular spindles and drop springs, but your venturing outside of my knowledge :)

[JoshStratton]

My issue is that I already have the Baers and they have the dropped spindles already installed. I guess I could remove them and have the Baers installed on the original spindles. I could always sell the dropped ones.

[zbugger]

Go ahead and use the spindles. I think you got misinformed. They usually base that measurement on swapping from drums to disks. I highly doubt you're doing that on your '79. It should most likely be the same. Not only that, but the difference would be overall. That means that it would be .25" on either side if it really was that much.

As for the drop, you'd be getting pretty low with the Hotchkis springs and the drop spindles. Otherwise, I'd say to just use the spindles. If you want a firmer ride, get the heavy duty stock replacement springs.

[yody]

or get springs made for you, or pick some from afco or something. The brakes probably won't work on a non dropped spindle because the rotor is higher up, so the mounting bracket has to be taller too

[JoshStratton]

I guess my big worry right now is the scrub radius. I am really worried that the car will be unsafe or I will be rotating my tires every other week to keep up.

So it sounds that what I am planning with the front and rear suspension will still work then?

[yody]

I don't think you should worry about it much, as far as i know (?) scrub radius isn't going to have anything to do with tire wear, and you would need to figure out approxitmly how much the spindle is going to change it, i doubt it will be unsafe

[graycamaro]

correct me if I am wrong but wont the upper and lower balljoints stay in the same place even with a lowering spindle and if it does shouldnt the scrub radius stay the same.

[hotrod]

Kuhlryde I got the latest application guide here from Baer and the only fbody that will have a wider track is on some applications with the 3rd gen. I don't think you've got anything to worry about with the wider track issue.

[JoshStratton]

Kuhlryde I got the latest application guide here from Baer and the only fbody that will have a wider track is on some applications with the 3rd gen. I don't think you've got anything to worry about with the wider track issue.
Awesome! That is exactly what I was hoping for. Thank you!

[hotrod]

correct me if I am wrong but wont the upper and lower balljoints stay in the same place even with a lowering spindle and if it does shouldnt the scrub radius stay the same.

I think what happens is you move the point at which the line drawn from the upper thru the lower ball joints intersection with the tire centerline to some point below the ground.

[79T/Aman]

scrub radius will increase as the spindle pin is raised, the ball joints do stay in the same place, the increase in scrub radius would be about 1/2" for a 2" pin height change, you could get wheels with 1/2" more back spacing but make sure that it would fit your car first.

[hotrod]

You can compensate for this with more backspace on your wheel which was stated earlier I think. With the VBP lower arms I can actually run a 17"X9" wheel with 5-1/2" BS. Had em on there for a while.

Heh Heh we're all typing fast and furious here :)

[yody]

I think what happens is you move the point at which the line drawn from the upper thru the lower ball joints intersection with the tire centerline to some point below the ground.

The scrub radius is measured at the ground level, where the tire is sitting on the ground, so moving the pin up, moves the wheel up but the the KAI stays the same. So you are know measuring at a point higher up, which will make the distance larger, effectively increasing the scrub radius(sounds cool huh :) ) pretty simple if you draw it out. I am wondering just how much 1/2" is going to affect the steering feel in the real world.

[hotrod]

Yep. Tell you what Kuhlryde I'll trade you my standard baer spindles for your dropped spindles. :) J/K

[hotrod]

hey yody were you at the pro touring dinner?

[graycamaro]

can someone clear up how exactly to measure scrub radius I am haveing a hard time understanding the previous explanations.


also would the spindles have any effect else where such as bump steer?

[hotrod]

I dont think the spindle height would have any affect on bump steer. Yody's first explanation on the first page is a good explanation. If I could draw it out it would easy to show you. :)

[yody]

hey yody were you at the pro touring dinner?
yeah i was there, I was the one clapping really slow at odd times :2nd:

[zbugger]

Chris, yes Yody was at the dinner. He was the one that looked like Slim Shady.

graycamaro, go to the library and ask for the June '05 issue of Popular Hotrodding Magazine. There is an article in there that explains scrub. It's easy once you see it.

[yody]

can someone clear up how exactly to measure scrub radius I am haveing a hard time understanding the previous explanations.


also would the spindles have any effect else where such as bump steer?
do some searches on scrub radius, that should set you up. I am not sure on the bump steer, but my first guess would be that it would not affect it, as the only thing that is changing is the wheel is moved farther up, but the suspension compression and tie rod angle is still the same.

[hotrod]

I had always thought that the best way to lower a car was by using dropped spindles. True or no? Yody were you one of the lucky ones that won something realy cool? :)

[yody]

last year i won the $1,000 air ride certificate, this year i won $100 ron davis certificate. Whats funny is I always thought drop spindles were a really bad idea, bet never knew why? In this application they actually don't seem like a bad idea? but not sure if there is something else hidden someone can point out

[hotrod]

So where's the air ride system? :) Do I see a new fuel tank in your future? Could be time to try out that new EFi you've been oggling. :)

[yody]

ron davis makes radiators......already have one :)

[hotrod]

Heh Heh I'll bet you wouldn't turn down those brakes they gave away. I know I wouldn't.

[yody]

yeah if you can afford the $3,000 for the rear brakes that you would have to buy to get the fronts for free............

[hotrod]

Argh, that's right.

[jeffandre]

Mark, most everything you say makes sense. I don't know if you're familiar with the VBP monoleaf front suspension but that is what I have and in order to get the ride height down there I have had to adjust the bolt as far as it will go and the camber is hard to get to go negative. With 2" dropped spindles I hope to get the ride height where I want it and get the lower arm back to the correct angle. Hey Boyd and Kuhlryde pics are in my garage.

Chris,
I also have the full VBP system. I changed the main bolt for a larger diameter, longer grade 8 bolt in order to lower the car to the limit. I have about 1" from LCA to frame, maybe a tad more. I had to shave my bumpstops. I will be using the upcoming ATS AFX spindles, so I expect the 'pin' height to be close to stock, maybe a minor amount upward, which will lower the car some more. I installed Del-a-lum bushings in my control arms, custom machined to move the UCA rearward and the LCA forward. I currently have -1.5 camber and +5 caster.

[jeffandre]

You can compensate for this with more backspace on your wheel which was stated earlier I think. With the VBP lower arms I can actually run a 17"X9" wheel with 5-1/2" BS. Had em on there for a while.

Heh Heh we're all typing fast and furious here :)

Chris,
You can go with increased BS if you go with a 19-20" wheel. I had 17x9.5's (from an 89 Vette) and they ran pretty much at the fender edge, which is too far out for my liking as I like the tire tucked inside the fender edge in order to lower the car. I switched to 19x10's with 7.25" bs and I have just the right amount of clearance everywhere now. The VBP control arms are great for wheel clearnace, no funky bulges anywhere, just straight edges, I love them!

[Mean 69]

correct me if I am wrong but wont the upper and lower balljoints stay in the same place even with a lowering spindle and if it does shouldnt the scrub radius stay the same.

I thought about this a little more, and I think Yody is correct. I was thinking of the change while holding the relative distance from the hub face to the KAI line constant before and after the change, but because KAI is not 0 degrees, it would actually create a narrower wheel mounting distance, (along with a lower scrub radius), but this is not what they likely do. They must use a longer pin at the same time as moving it up to make the wheel mounting distance the same as factory, in this case, the scrub radius would increase a bit. Good catch!

I wouldn't sweat it too much, no question scrub radius is a really important element, but there isn't a whole lot you can do about short of going with dramatically different parts, and it was never good from the factory to begin with. As for tire wear, here again, I wouldn't sweat it, the change will likely be incrementally small, and I'd guess that it wouldn't be a big issue as long as you are aligned correctly. Besides, your tires should only live about half their rated life anyway, due to driving like a madman around corners!

I wish I had some specific numbers, sorry for the lack of real data, but it is a great discussion.
Mark

[graycamaro]

Thanks for all the input I went back to the herb adams chasis enginering book and found the picyure of scrub radius and understand now. Using a drop spindle would increase scrub radius.

But my question now is what do you think is the lesser of two evils to get the car to the right height. I have eibach springs which are supposed to drop the car approx 1in but I have hear that that is not true in most cases there won't be that much drop so I was thinking about drop spindles in conjunction with the eibach springs rather than cutting the springs or buying shorter spring to get the ride height right. I am concerned with shorter springs reduceing the amount of suspension travel because this is a street car to be used as a daily driver and will see a fair amount of potholes and uneven surfaces.

Also does anyone make drop spindles for these cars with the 12in brakes?
Thanks

[hotrod]

Chris,
You can go with increased BS if you go with a 19-20" wheel. I had 17x9.5's (from an 89 Vette) and they ran pretty much at the fender edge, which is too far out for my liking as I like the tire tucked inside the fender edge in order to lower the car. I switched to 19x10's with 7.25" bs and I have just the right amount of clearance everywhere now. The VBP control arms are great for wheel clearnace, no funky bulges anywhere, just straight edges, I love them!

COOL! Another 2nd genner with a VBP front end!
Yes the LCA's are great. However, with 17X9's I would eventually get into interference with the sway bar so I'm running narrower wheels for the street. The interference is pretty minor so it makes sense that 19" or 20" wheels would clear. I'm contemplating some race tires and wheels for track days down the road so I'll keep that in mind Jeff. What shocks did you end up with? I still have the KYB's that they supplied and I am in sore need of rebound control on anything bigger than a ripple in the road. :)

[jeffandre]

COOL! Another 2nd genner with a VBP front end!
Yes the LCA's are great. However, with 17X9's I would eventually get into interference with the sway bar so I'm running narrower wheels for the street. The interference is pretty minor so it makes sense that 19" or 20" wheels would clear. I'm contemplating some race tires and wheels for track days down the road so I'll keep that in mind Jeff. What shocks did you end up with? I still have the KYB's that they supplied and I am in sore need of rebound control on anything bigger than a ripple in the road. :)

My 19x10's touch the sway bar, and at that point the steering radius is a bit tighter than a 3rd Gen F-body, so I will probably modify the steering box if I cannot make another type of steering stop. I plan to change the front sway bar (have Herb Adams now) to a hollow-type with slim aluminum ends for greater tire/wheel clearance as well.

I have always run Koni's, but will change to the recommended Bilstein's (about $280 for all 4) soon. The Koni's are too stiff for this setup, even set at full soft, and their rebound rates are too weak. VBP tech told me that the Bilstein's are considered the best shock for our springs, and not to get multi-adjustable shocks as the odds of getting them set right are slim. Oh well, I like the price of the Bilstein's.

[hotrod]

I didn't want to hear that. So yours aren't the double adjustables?I was really hoping that the double adjustables would work. When are you going to try the Bilsteins? Maybe I'll wait until you try them and can give me a report. :) So do you suppose 19X9's would clear the sway bar?

[jeffandre]

I didn't want to hear that. So yours aren't the double adjustables?I was really hoping that the double adjustables would work. When are you going to try the Bilsteins? Maybe I'll wait until you try them and can give me a report. :) So do you suppose 19X9's would clear the sway bar?

I have 7.25" backspacing, and I think a 19x9 with 6" bs would fit fine using the VBP UCA's and LCA's. My wheels are 1.75" inside the fender edge. I have the same turing radius as a 3rd Gen F-body, so no worries. I also have a 3rd Gen close ratio steering box, darn good upgrade for the money imo. I plan to get a hollow sway with thin aluminum arms for extra clearance anyway.

My Koni's are single-adjustable, and if I had the money I would try to get a set of dual-adjustables that I could adjust from the driver's seat so that I would have a chance to get them right. I will get the Bilstein's next year, after the ATS AFX spindles and massive brakes, so it will be a while before I know how the suspension feels. I just remember the Koni's being rock hard, and I could barely bounce the front or rear much more than 1/4" with my 200# of body weight. I guess I will try bouncing the car without shocks, then with the Bilstein's jsut to see how it feels.

[hotrod]

AGR told me that the '80 and up fbody steering boxes are the same. Not sure if that's true or not. I went with their 12:1 box and it works pretty well. I read in a post on another forum that they thought the rock hard suspension was more due to stiction in the bushings but you have already replaced yours with GW's/ Doesn't sound like that's the problem to me.

[jeffandre]

AGR told me that the '80 and up fbody steering boxes are the same. Not sure if that's true or not. I went with their 12:1 box and it works pretty well. I read in a post on another forum that they thought the rock hard suspension was more due to stiction in the bushings but you have already replaced yours with GW's/ Doesn't sound like that's the problem to me.

Chris,
You're right, the poly had everything locked up. I could not raise the spindle by hand with the poly-bushed arms. Now it moves smoothly with minimal effort (spring and shock off of car). I am guessing that will make a big difference in front end handling/feel/responsiveness. I can't wait to drive it (hurry up ATS, I want that AFX spindle setup bad...).

[hotrod]

Jeff were GW's bushings a direct replacement before you machined them?

[jeffandre]

Jeff were GW's bushings a direct replacement before you machined them?

I got the GW bushings for stock 71 Camaro cotnrol arms. I did have to get the larger bolts for the rear of the lower arms, which I think are stock size on later 2nd Gens.

I had to machine the uppers a little, using the GW offset shafts as well. I used some extra steel washers to move the bushings/crossshafts forward in the arms, which essentially moved the upper arms rearward for increased caster.

The lowers required a lot more machining, and I installed them from the rear, which moved the arms forward, again adding a bit of caster.

[hotrod]

I used GW's bushings on a '80 Z28 a while back and I was blown away by the smooth operation. These were stock arms and they would drop on their own with just the weight of the arms yet they were solid as could be. Try doing that with stock bushings. Also the arms on the VBP susoension required a lot of effort to move when I first installed them.