6 speed automatic?
Thread Starter
Instructor
Joined: Sep 2014
Posts: 243
Likes: 23
From: Vancouver WA
6 speed automatic?
My searches turned up very little so here my question.
Has anyone, or is it even possible, to install a later model 6spd AUTOMATIC transmission in our beloved C4s?
I believe 2 additional forward gears would wake my 92 coupe right up, and maintain its ease of driveability.
Any info greatly appreciated.
Has anyone, or is it even possible, to install a later model 6spd AUTOMATIC transmission in our beloved C4s?
I believe 2 additional forward gears would wake my 92 coupe right up, and maintain its ease of driveability.
Any info greatly appreciated.
Team Owner
Joined: Oct 2004
Posts: 81,241
Likes: 3,062
From: altered state
St. Jude Donor '05
GMPP or Pace Performance probably sells it witha controller
That would be the cats meow....maybe even sway me from a stick.
Let us know what you find..probably pricy but worth it. Not a huge fan of the typical 4 spd OD gm stuff unless you throw a whole lot of money at it.
TCI may have a 6 spd auto too come to think of it .
That would be the cats meow....maybe even sway me from a stick.
Let us know what you find..probably pricy but worth it. Not a huge fan of the typical 4 spd OD gm stuff unless you throw a whole lot of money at it.
TCI may have a 6 spd auto too come to think of it .
Racer
Joined: Jun 2010
Posts: 365
Likes: 27
From: Shelby Township Michigan
Checkout gear vendors overdrive. Might be an option and as previously mentioned it won't be cheap. I bout one for my 67 Coronet 500 with a 727 which makes it a six speed. Cool part is I have 411 gears in the rear and when i install the OD I'll actually be able to drive it on the highway. I was going to convert the vette but decided to do a six speed conversion.
Burning Brakes
Joined: Nov 2013
Posts: 914
Likes: 277
From: St. Petersburg FL
THIS!
By "wake up" your car, I should think you mean its acceleration. The best place to start is at the rear end. A stock rear end for a C4 A4 will have 2.59:1 gears. The "Performance Ratio" for an A4 Corvette is 3.07:1. That's a 16% mechanical advantage for acceleration.
If you were to go from 2.59:1 to 3.36:1, you'll get a 23% mechanical advantage over a stock rear end and that's something you will feel, IMMEDIATELY! You can probably get that done for well under a grand and, if you still think your car's a little sleepy, THEN you can start fooling with engine mods.
Just my $ .02.
By "wake up" your car, I should think you mean its acceleration. The best place to start is at the rear end. A stock rear end for a C4 A4 will have 2.59:1 gears. The "Performance Ratio" for an A4 Corvette is 3.07:1. That's a 16% mechanical advantage for acceleration.
If you were to go from 2.59:1 to 3.36:1, you'll get a 23% mechanical advantage over a stock rear end and that's something you will feel, IMMEDIATELY! You can probably get that done for well under a grand and, if you still think your car's a little sleepy, THEN you can start fooling with engine mods.
Just my $ .02.
Thread Starter
Instructor
Joined: Sep 2014
Posts: 243
Likes: 23
From: Vancouver WA
Thanks everyone.
I already have the 3.07 gears. I just think it takes too long under acceleration to get through the gears. A closer gear ratio and more cogs would allow the engine to get into the power curve faster off the line and stay there through the shifts. Am I right?
I already have the 3.07 gears. I just think it takes too long under acceleration to get through the gears. A closer gear ratio and more cogs would allow the engine to get into the power curve faster off the line and stay there through the shifts. Am I right?
Burning Brakes
Joined: Nov 2013
Posts: 914
Likes: 277
From: St. Petersburg FL
Thanks everyone.
I already have the 3.07 gears. I just think it takes too long under acceleration to get through the gears. A closer gear ratio and more cogs would allow the engine to get into the power curve faster off the line and stay there through the shifts. Am I right?
I already have the 3.07 gears. I just think it takes too long under acceleration to get through the gears. A closer gear ratio and more cogs would allow the engine to get into the power curve faster off the line and stay there through the shifts. Am I right?
Try 3:70's!
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Team Owner
Joined: Dec 1999
Posts: 34,873
Likes: 487
From: Lacey WA RVN 68-69
NCM Sinkhole Donor
The biggest problem would be engineering a kit to install a 6-speed auto into the C4. A modified trans tailshaft to hook to the C-beam would be a requirement as would be a shorter output shaft and a shortened driveshaft.
I would think the trans would need to be electronically controlled like the 93 and later trans. It might be a problem converting a 92 given the cables. And depending on how long that trans would be could be an issue with finding space on the floor pan. Same with the width of the case and allowing room for the exhaust system.
I would think the trans would need to be electronically controlled like the 93 and later trans. It might be a problem converting a 92 given the cables. And depending on how long that trans would be could be an issue with finding space on the floor pan. Same with the width of the case and allowing room for the exhaust system.
Burning Brakes
Joined: Nov 2013
Posts: 914
Likes: 277
From: St. Petersburg FL
The biggest problem would be engineering a kit to install a 6-speed auto into the C4. A modified trans tailshaft to hook to the C-beam would be a requirement as would be a shorter output shaft and a shortened driveshaft.
I would think the trans would need to be electronically controlled like the 93 and later trans. It might be a problem converting a 92 given the cables. And depending on how long that trans would be could be an issue with finding space on the floor pan. Same with the width of the case and allowing room for the exhaust system.
I would think the trans would need to be electronically controlled like the 93 and later trans. It might be a problem converting a 92 given the cables. And depending on how long that trans would be could be an issue with finding space on the floor pan. Same with the width of the case and allowing room for the exhaust system.
The best advice you've gotten so far (given that you already have a 3.07 rear) is forced induction. That will definitely wake up the car!
Thread Starter
Instructor
Joined: Sep 2014
Posts: 243
Likes: 23
From: Vancouver WA
Thanks again everyone. One of the places suggested, TCI, had what looked like a 6spd auto for SBC listed at $6,600! That's not too far from the price of the car lol. And it said nothing about it fitting in a C4.
It was just a whim I thought I would chase and see where it lead. I may check into changing the rear gears out.
I'm always looking to upgrade my toy in any way possible, and since it is running well and everything seems to be working as it should (except for an intermittent door chime), I started dreaming big.
It was just a whim I thought I would chase and see where it lead. I may check into changing the rear gears out.
I'm always looking to upgrade my toy in any way possible, and since it is running well and everything seems to be working as it should (except for an intermittent door chime), I started dreaming big.
Team Owner
Joined: Dec 1999
Posts: 34,873
Likes: 487
From: Lacey WA RVN 68-69
NCM Sinkhole Donor
Thanks again everyone. One of the places suggested, TCI, had what looked like a 6spd auto for SBC listed at $6,600! That's not too far from the price of the car lol. And it said nothing about it fitting in a C4.
It was just a whim I thought I would chase and see where it lead. I may check into changing the rear gears out.
I'm always looking to upgrade my toy in any way possible, and since it is running well and everything seems to be working as it should (except for an intermittent door chime), I started dreaming big.
It was just a whim I thought I would chase and see where it lead. I may check into changing the rear gears out.
I'm always looking to upgrade my toy in any way possible, and since it is running well and everything seems to be working as it should (except for an intermittent door chime), I started dreaming big.
On a side note, do you live somewhere in Clark County where emissions testing is not required?? Certain ZIP codes don't require testing.
If you don't have to go thru testing, you may want to consider installing long tube headers and a true dual exhaust. Even a good cat-back system from Corsa or Magnaflow will be a big help. Then go visit Tom Wong at Wong's Performance Engineering for a tune.
He's located on Highway 99 in Northeast Hazel Dell.
Instructor
Joined: May 2014
Posts: 152
Likes: 1
From: Fayetteville NC
4L80E 6-speed
My searches turned up very little so here my question.
Has anyone, or is it even possible, to install a later model 6spd AUTOMATIC transmission in our beloved C4s?
I believe 2 additional forward gears would wake my 92 coupe right up, and maintain its ease of driveability.
Any info greatly appreciated.
Has anyone, or is it even possible, to install a later model 6spd AUTOMATIC transmission in our beloved C4s?
I believe 2 additional forward gears would wake my 92 coupe right up, and maintain its ease of driveability.
Any info greatly appreciated.
I am planning to call them and see if they will do the same for our 4L60/65Es. Seems like it could be done, and there are a lot of 4L60/65Es out there in C4s, C5s, other cars, light trucks, etc. A C4/C5 would really walk through the gears with the engine staying in the power curve instead of dropping out and having to climb back in at WOT.
With a 4L60E 6-speed we do not need a new gear set. Our first gear already is low at 3.059 and we would have 5 gears to 1:1. The gear spread would be:
Gears and Spacing
3.059
2.129 1.437 - new gear
1.625 1.310
1.131 1.437 - new gear
1.000 1.131
0.696 1.437
Burning Brakes
Joined: Apr 2009
Posts: 1,228
Likes: 10
From: That one city...you know that one. Idaho
Powertrain Control Solutions makes a modified valve body and gear set for the 4L80E which will give it 5 gears without a new gear set and 6 gears with a new lower first gear set with better gear spacing, PCS Controller, and modified valve body. Price about $2000 + rebuild.
I am planning to call them and see if they will do the same for our 4L60/65Es. Seems like it could be done, and there are a lot of 4L60/65Es out there in C4s, C5s, other cars, light trucks, etc. A C4/C5 would really walk through the gears with the engine staying in the power curve instead of dropping out and having to climb back in at WOT.
With a 4L60E 6-speed we do not need a new gear set. Our first gear already is low at 3.059 and we would have 5 gears to 1:1. The gear spread would be:
Gears and Spacing
3.059
2.129 1.437 - new gear
1.625 1.310
1.131 1.437 - new gear
1.000 1.131
0.696 1.437
I am planning to call them and see if they will do the same for our 4L60/65Es. Seems like it could be done, and there are a lot of 4L60/65Es out there in C4s, C5s, other cars, light trucks, etc. A C4/C5 would really walk through the gears with the engine staying in the power curve instead of dropping out and having to climb back in at WOT.
With a 4L60E 6-speed we do not need a new gear set. Our first gear already is low at 3.059 and we would have 5 gears to 1:1. The gear spread would be:
Gears and Spacing
3.059
2.129 1.437 - new gear
1.625 1.310
1.131 1.437 - new gear
1.000 1.131
0.696 1.437
Instructor
Joined: May 2014
Posts: 152
Likes: 1
From: Fayetteville NC
This sounds very similar to the TCI 6 speed. It is supposed to be based on a 4L80E, and is about the same size.
2010 SEMA V8TV Video Coverage: TCI 6X 6 Speed Automatic Overdrive Transmission - YouTube
2010 SEMA V8TV Video Coverage: TCI 6X 6 Speed Automatic Overdrive Transmission - YouTube
I hope to call PCS this week. PCS already sells a controller with the 4L80E, so no trouble getting a programmable controller for a 4L60E.
Maybe I should call TCI as well?!
Last edited by afgunn; Feb 24, 2015 at 04:45 PM.
Instructor
Joined: May 2014
Posts: 152
Likes: 1
From: Fayetteville NC
I am thinking of buying a 4L60E shop manual and seeing if it could be done and how. I know another solenoid valve would need to be installed in the right place to apply OD on 1st gear. This would give us a 5-Speed with the added gear ratio of 2.129 between our current 1st and 2nd. Then a PCS programmable controller for about $700. Not to bad in my opinion. Seems to me there are a lot of C4, C5, F-body, and light trucks out there with 4L60/65/70Es! Just my 2 cents.
Melting Slicks
Joined: Feb 2003
Posts: 2,662
Likes: 806
From: Saskatoon Sask.
Well...., I just got off the phone with PCS. They said a 5/6-speed for the 4L60/65/70 is NOT even on their radar!? He said the 4L60E fluid flow and valve body is slightly different than the 4L80E. He did not say that it was impossible, just they are not interested.
I am thinking of buying a 4L60E shop manual and seeing if it could be done and how. I know another solenoid valve would need to be installed in the right place to apply OD on 1st gear. This would give us a 5-Speed with the added gear ratio of 2.129 between our current 1st and 2nd. Then a PCS programmable controller for about $700. Not to bad in my opinion. Seems to me there are a lot of C4, C5, F-body, and light trucks out there with 4L60/65/70Es! Just my 2 cents.
I am thinking of buying a 4L60E shop manual and seeing if it could be done and how. I know another solenoid valve would need to be installed in the right place to apply OD on 1st gear. This would give us a 5-Speed with the added gear ratio of 2.129 between our current 1st and 2nd. Then a PCS programmable controller for about $700. Not to bad in my opinion. Seems to me there are a lot of C4, C5, F-body, and light trucks out there with 4L60/65/70Es! Just my 2 cents.
Instructor
Joined: May 2014
Posts: 152
Likes: 1
From: Fayetteville NC
This sounds very similar to the TCI 6 speed. It is supposed to be based on a 4L80E, and is about the same size.
2010 SEMA V8TV Video Coverage: TCI 6X 6 Speed Automatic Overdrive Transmission - YouTube
2010 SEMA V8TV Video Coverage: TCI 6X 6 Speed Automatic Overdrive Transmission - YouTube
The least expensive and easiest (?) would be to modify the 4L60E valve body to give us an extra gear between 1st and 2nd - a 5-Speed trans. I feel the same about the distance between 1/2 and 2/3. I think the most help could be had between 1/2. In 3rd at 5100rpm with my 2.59 rear end, I am going 152mph. I will probably never see that unless I can get on a track. Not sure I want to swap out the 2.59 for a much steep gear because that would hurt highway mileage plus running 2500rpm or greater at 75mph.