6L90e in a 67' Camaro with a L92 --will it fit

[Bobs 67Camaro]

I came across a L92/6L90e combo out of an '09 Denali with 1700 miles on it. It is a complete package with harness, starter, acc., and exh. manifolds. They are asking $5000 for the set.

It seems like a good deal to me! I would like to put it in my 67 Camaro, and was wondering if the tranny would clear the tunnel (I'm guessing not). If not, I would sell the 6L90e and buy a T56. I would assume I could get 1500-2000 for the 90e.

If the tranny were to fit, how much would it cost todo paddle shifters? I know twist machine sells kits.

Any thoughts? Thanks for your imput!

[Poorhousenext]

Most of the answers to your questions can be found in the thread below.

Contrary to what another member here posted about car in the thread no being on the road yet in another 6L thread, it has been on the road for 2 years an it is not a custom car, but a daily driver.

http://www.ls1tech.com/forums/conver...o-does-go.html

[Bobs 67Camaro]

I found that one too. It's a good right-up! Looks like the top of the tunnel has to come off....

Do you have to take the tunnel off? I suppose it's a balance of pan clearance vs. tunnel?

Thanks for the link. Do you know if he every put paddles in it?

[Poorhousenext]

I found that one too. It's a good right-up! Looks like the top of the tunnel has to come off....

Do you have to take the tunnel off?

I'm going to let you decide that, based on pictures and words owner posted in his thread.

Owners words:

Had some PM's re ground clearance and the tunnel revisions, so some additional shots showing current ground clearance:

One shows the trans clearance is around 4.75". (120mm). This is with the trans sitting through the tunnel roof cutout by an average 0.7-0.8".

The other shows front crossmember clearance. It is around 6.9" (175mm).
The car overall will be 1.5 to 2" lower once finished. Say 5" at the front cross member, 2.75-3" at the trans pan (stock depth 90 pan). If the tunnel had not been cut out, and assuming around 1/4-3/8" clearance from top of trans to tunnel, the trans pan would be around an inch lower again: 1.75-2" ground clearance.

I suppose it's a balance of pan clearance vs. tunnel?

I don't think so. Looks to be the product of combination of engine mounted in stock location using mounting plates (same as my 66 vette) and correct trans alignment from above pictures.

Do you know if he every put paddles in it?

Last time we corosponded, about a year ago, he was looking into making his on. He was using momentary contact switch mounted on dash to manual shift trans. He did find a way to display gear trans was in when in manual mode using DashDaq.

Think he decided to just let trans shift it's self form what he posted in automatic forum on same site a week or so ago. Take a good look at the 6L's gear splits and I think you will see why. Think the trans in Sport Mode does up shifting and down shifting better than he expected in twisties.

[Bobs 67Camaro]

Thank you for the thoughts. It looks like a little more cutting then I care to do with my car.

How would the 6L90e fit in your vette? I would think you'd have less room then me?

There are some aftermarket parts coming out for these trannies (so they can handle big power).

[Poorhousenext]

Thank you for the thoughts. It looks like a little more cutting then I care to do with my car.

How would the 6L90e fit in your vette? I would think you'd have less room then me?

A 6L90 would have been more of a fit problem for me than the 6L80E was. It's little bit of extra length and the size of yoke for it would have required me to have to enlarge width of tunnel to fit rear of trans as well as heigth. It's the trans height at back of it that causes most of the problem with tunnel. You should be able to see this in pictures I posted in prior post comparing it with 4L60 trans.

As we lowered the body, we were cutting the tunnel's top as we went. You can see the height of the rear of trans is were problem starts, and continues up to where bell housing is same size as other GM auto's.



You may be able to see were cuts to tunnel ended at front of tunnel to fit trans where it fairs into it's bell housing. I also have advantage of being able to space car's body a little higher off frame, before that becomes a problem with mounting bumper brackets.

There are some aftermarket parts coming out for these trannies (so they can handle big power).

Who is making them? I follow threads on 6L's so I can stay up to date on making these transmission last with big TQ & HP engine. Below thread has post from transmission builder that has been trying to make them last. One post from drag racer that he had finally got to 86 passes without trans failing. Problems will be overcome just as with any prior automatic transmissions.

http://www.ls1tech.com/forums/automa...6spd-auto.html

http://forums.corvetteforum.com/c6-t...y-be-over.html

http://www.ls1tech.com/forums/automa...-upgrades.html

$1,000-$1500 dollars seems to be average used price for one. Buy the one with wrong tail housing for your application and you will be looking at another $500.00+ in parts to correct that. If or when it needs rebuilding, it will cost you more than rebuilding any other GM auto without performance upgrades to it's weak mechanical parts. Soft upgrade parts will be about same price.

I want more people to use this trans as that will speed up development of upgrade parts for them. Like you, a lot of people don't want the hassle of fitting one in their car and all the hassles that fitting causes with fitments of other parts tunnel mods could affect.

Like I said in my first post, I used it because it's was a novelty item in cars back in 2007 when I bought trans new from GM. For me it was just a way to try to make car sound impressive because it has a "6 speed auto". As far as I can tell from Internet, it now be be one of three 63-67 Midyear Corvettes with one.

Rick Hendrick is using a couple of 6L90E's in builds he is doing using LS9 engines.



When I decided to do the 4L80E based 6 speed in my 64 Vette coupe, it fit in the tunnel. Only problems were, I could not install main wire harness on left side of it or transmission cooling lines on right side until I widen the tunnel to accommodate them...lol Not problems with 6L80E.

[Bobs 67Camaro]

It looks great!

I believe RPM Transmission, in Indiana, builds them. Rodney is the owner.
http://www.rpmtransmissions.com/

John at speartech may also know who else builds them. They are a very tunable transmission.

[Bobs 67Camaro]

Another:

http://www.importperformancetrans.co...sion-4339.html

[Poorhousenext]

It looks great!

I believe RPM Transmission, in Indiana, builds them. Rodney is the owner.
http://www.rpmtransmissions.com/

John at speartech may also know who else builds them. They are a very tunable transmission.

RPM thinks highly of the 6L trannies. You can tell from a couple of their post in one of the links.

Sure they are tunable, but it seems there is a disconnect on how to tune them if you can believe RPM Transmissions.

Originally Posted by Jeremy@RPMTransmissions
Other than the novelty of the 6 speed auto, is there any other reason you are considering the swap? The 6L80e is a nightmare at the moment. No one has perfected the tuning on the A6. If someone were to develop a true 100% stand alone operating system for the 6L80e then it might be a viable alternative to the 4L60e and 4L80e But unfortunately right now it isn't.

The 6L80e is 100% computer controlled. So the engine and transmission tuning are dependet on eachother. The ways people have been tuning engines for years is now causing issues with the 6L80e transmissions because it effects the pressures in the transmission. I am by no means a tuner, but we have rebuilt quite a few 6L80e transmissions that have been roasted by tuners experimenting with their transmission tuning trying to get rid of the flairs between shifts and whatnot. Take a look over at corvette forum and you will see all the headaches that have come along with the 6L80e transmissions.

I'll stay with just driving the 6L80E car for now, and do my Pro Touring competitions with the 4L80E based 6 speed with it's lifetime warrenty.

They make preformed tunnel pieces that make it easy to patch the 67's tunnel. Cut and weld.

[Bobs 67Camaro]

I can understand why you would do so (if I had a lifetime warranty, I would do the same).

Is there a substantial difference between the 6L80e and the 6L90e? I know the 6L90e is slightly longer....

It was my understanding that the 6L80e came in all of the SUV/Light duty truck applications (Denali, Escalade, etc), while the 6L90e came in medium duty trucks (2500 and 3500 pick-ups, 1 ton HD's, and fleet trucks. Is this true? Is the 6L90e more desirable if fitment is no issue?

THanks again.

[Poorhousenext]

I can understand why you would do so (if I had a lifetime warranty, I would do the same).

Is there a substantial difference between the 6L80e and the 6L90e? I know the 6L90e is slightly longer....

It was my understanding that the 6L80e came in all of the SUV/Light duty truck applications (Denali, Escalade, etc), while the 6L90e came in medium duty trucks (2500 and 3500 pick-ups, 1 ton HD's, and fleet trucks. Is this true? Is the 6L90e more desirable if fitment is no issue?

THanks again.

The 6L90E mechanicals like output shaft, and gears are stronger. Sort of like comparing a 4l65E to a 4L80E, on those.

The thread on the Camaro with 6L90E goes into some of the differences between the 80 & 90. Those beefier parts should withstand an are rated to withstand higher HP & TQ applications by GM. GM power train may still have diagrams up that you can compare one to the other.

Because of application use, the 6L80E are the ones you see being abused. The shafts and gears seem to be able to handle the abuse.

The supercharged Caddy does use the 6L90. Most of those will never be abused at strip. So any 90 problems will have to feed off that discovered in the 80's being the same. Probably be a while before more 90's show up at strip in older cars to see how much better they can handle abuse.

6L80E/90E

1st: 4.03
2nd: 2.36
3rd: 1.53
4th: 1.15
5th: 0.85
6th: 0.67

4L80E based 6 speed

1st: 2.97
2nd: 2.23
3rd: 1.57
4th: 1.18
5th: 1.00
6th: 0.75

Take a good look at the 6L's gear ratios again. 4.03 1st gear. Try downshifting from 2nd to it in a tight turn and then upsifting to 2nd with it's rpm drop. You really have to watch your rpm when you down shift are you will over rev engine in a heart beat with that kind of drop. Then with no 1.0 to 1.0 gear before going from 1.15 to OD of .85 that leave you with only 3 really usable gears in competition.

Compare the 4l80E based 6 speed gears to a manual trans and they match up. Closer splits to keep you in engine power's band. Just wish it could support engine braking to help save brakes on road course. Even at strip, it should be able to go thru trap in 4th gear.

Now there is a big difference in TQ converter stalls I'm using between the cars. The 6L80 is stalled at 3200-3400 for straight line driving.

Because the 4L80 based 6 speed will be used for competitions that are not just straight line, it's converter is stalled only slightly higher than stock at 2500 rpm. Don't want RPM to flash to 3200-3400 when power is applied.

These are just my thought, right are wrong. You can come to your on conclusions on subject(s).

If you are not building a pro Touring car but just a straight line one dimensional car, then the 6L's aren't bad. My 66 vette has 3.07 rear end. In 1st gear, a C6 manual vette with 3.42 rear end in first would need to have a 4.60 rear end to match the 6L's first gear dig. It would need a 3.54 to match in 4th gear since the 6L has a 1.15 instead of 1.0 4th gear.

[aronhk_md]

Jake Shoe builds and sells the 4L80's, and he is a member of this forum. Sponsor I think. He indicated to me that he is able to build it with engine braking. That was just a few months ago, so I'm not really sure if he HAS built one as such, or if it is theoretical.

[Poorhousenext]

Jake Shoe builds and sells the 4L80's, and he is a member of this forum. Sponsor I think. He indicated to me that he is able to build it with engine braking. That was just a few months ago, so I'm not really sure if he HAS built one as such, or if it is theoretical.

Engine braking with 4L80E has been done.

When I talked with TCI and asked them if they could do it with the 6X their support dept said because of the way they achieve 6 gears, it would cause binding. Did TCI really spend time to see if there could be a way to it, maybe not.

If someone can pull it off, the trans become a game changer. Way to cool the fluid to allow all out road course runs longer than 30 min would be the next step, but there are product on the market now that can help with that.

Could someone else say Jake, be able to to it with the 4L80E based 6 speed he developing, he could do what TCI said is not possible with theirs.

Bowler transmission is supposed to be coming out with a 4L80E based 6 speed too, so they might be able to do it.

Lot of people seem to think TCI maintain the 0.75 is terrible. I don't have a problem with it. TCI targeted the 6X at the hot rod and street rod market use of older cars. These cars have the aerodynamic of 4' X 8' sheet of plywood in a hurricane compared to today car.

Also most of the engines use in them may not have the broad power band engines use in today cars, where engine builds TQ earlier in the power band an holds it higher longer to be able to get away with less mechanical advantage of a 0.67 or even 0.70 OD even at 1600 -1800 RPM at 70 mph. Cars with engines that have a bell shape TQ curve that doesn't come on until 3000 are above RPM way just benefit from that extra mechanical advantage of more RPM at cruise of a 0.75 OD. It's a basic split of a 6l80/90E's 0.85 and 0.67 OD.

When GM use the 6L80 in the G8 GXP, they had to used a 3.27 rear gear rather than even the 2.76 performance ratio option used in the C6 vette's with 6L80E. They had to do that due to cars weight and poorer aerodynamics to give it performance and maybe even better gas mileage than with a taller gear.

The manual trans version has a 3.70 rear gear. Do the math on the 6L80's 1.15 4th gear ratio and you see it matches the 1:1 manual ratio of 3.70. Another reason they had to use a 3.27 ratio is the 6L's lack of a 1:1 gear's mechanicals advantage to pull the G8 weight on top end. Your sucking wind up your rear when you max rpm out in 4th and trans shifts to the 0.85 5th gear too.

Maybe later this year I will be able to walk the talk on how both compare in similar cars, even though engines aren't the same and the one with the 6X weighs a minimum of 225 lbs more than the other one due to sound deadening and exhaust. Both cars have a 3.54/3.55 final non OD ratio, one with 3.07 and other with 3.54

My 6L80E car.



My 4l80E based 6X car.

[aronhk_md]

Beautiful cars. I too am very interested in an overdrive capable of engine braking. Currently there really isnt a good alternative I'm aware of in a 6 speed manual trans capable of handling the power my car puts down, while the 4L80 is easily capable of 1200+ HP. While a 6 speed based 4L80 would be ideal, I am not even in the ballpark to be able to afford the base 4L80 that can handle my car, seeing that its at least a $4500 investment with converter, adapter plate, computer and driveshaft....possibly more.

Whether Jake is involved in any 4L80 +2 conversions you'd need to ask him yourself. I doubt he has the resources to bring a +2 to market himself, but I wouldnt be surprised if he can modify one made elsewhere to perform differently. I DO know he understands the trans very well and has designed his own proprietary trans brake for it that from the description seems to be better than anything currently out there for it. His response to me when I inquired about engine braking is that he can do it. Since you say it has been done I believe it. Like you I don't know if I would believe TCI that the 4L80 +2 cant be made to do it. Often we find that there are people who say this or that cant be done.......until someone actually does it

If you do speak to Jake though I would be curious what his answers are to your questions.

[Poorhousenext]

Whether Jake is involved in any 4L80 +2 conversions you'd need to ask him yourself. I doubt he has the resources to bring a +2 to market himself, but I wouldnt be surprised if he can modify one made elsewhere to perform differently. I DO know he understands the trans very well and has designed his own proprietary trans brake for it that from the description seems to be better than anything currently out there for it. His response to me when I inquired about engine braking is that he can do it. Since you say it has been done I believe it. Like you I don't know if I would believe TCI that the 4L80 +2 cant be made to do it. Often we find that there are people who say this or that cant be done.......until someone actually does it

If you do speak to Jake though I would be curious what his answers are to your questions.

If I don't have my Jakes mixed up, here is his post to a thread on another forum when questioned about ETA of it.

http://www.ls1tech.com/forums/automa...onversion.html

Earlier thread mentioned in that one.

http://www.ls1tech.com/forums/automa...eeks-left.html

Right now there is no reason for me to bother him with question. I'm sort of locked in with what I have now. If his 4L80 based 6 speed will, then that would make me question TCI if they can modify their's to do the same. Course that predicated on how competitive I can make the car without it.

[aronhk_md]

Yes, thats the same Jake

[Bobs 67Camaro]

You Vettes look great!

[KHShapiro]

This thread is fantastic

[aronhk_md]

You think this is fantastic.........you should try sliced bread!

[robertjra]

do you have any updates on this thread