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Talking pure theoretical here. But was talking with a buddy about my vette (a 96 c4 lt1) While the 4l60e is alright. a 4L80E is better. But what was then brought up "imagine if you put the 10 speed in it" Which...what if. its a awesome trans that. wouldn't even notice the LT1 powering it. On that same coin. i also imagine its bigger in every, single way then the 4L60E. height, width, depth, WEIGHT, I imagine the trans tunnel would need MASSIVE surgery and so would the Cbeam. and ofc, completely new wiring setup, shifter linkage setup, etc. but would this even have any remote chance of fitting in the car? if not the 10 speed, 8L90-E? 6L80E???
Talking pure theoretical here. But was talking with a buddy about my vette (a 96 c4 lt1) While the 4l60e is alright. a 4L80E is better. But what was then brought up "imagine if you put the 10 speed in it" Which...what if. its a awesome trans that. wouldn't even notice the LT1 powering it. On that same coin. i also imagine its bigger in every, single way then the 4L60E. height, width, depth, WEIGHT, I imagine the trans tunnel would need MASSIVE surgery and so would the Cbeam. and ofc, completely new wiring setup, shifter linkage setup, etc. but would this even have any remote chance of fitting in the car? if not the 10 speed, 8L90-E? 6L80E???
Why stop there? Maybe even an Allison from an ore truck!
Talking pure theoretical here. But was talking with a buddy about my vette (a 96 c4 lt1) While the 4l60e is alright. a 4L80E is better. But what was then brought up "imagine if you put the 10 speed in it" Which...what if. its a awesome trans that. wouldn't even notice the LT1 powering it. On that same coin. i also imagine its bigger in every, single way then the 4L60E. height, width, depth, WEIGHT, I imagine the trans tunnel would need MASSIVE surgery and so would the Cbeam. and ofc, completely new wiring setup, shifter linkage setup, etc. but would this even have any remote chance of fitting in the car? if not the 10 speed, 8L90-E? 6L80E???
Get your car up on a lift and look at the clearance you have now with the 4L60E. Get some basic dimensions from 10 speed and get an idea of the clearance that one will need. You could widen the tunnel a little, but you have to leave room for the seat and the pedal box. The 4L60 can be re-built with much stronger internals and you can avoid all fitment problems.
IF you're looking for more gears, might also call Gear Vendors and see if they've ever put one in a C4. I have one behind the the TH700 in my Camaro, giving me effectively an 8-speed transmission. It's so much fun... and the double overdrive gets me ~28-30 mpg on the highway once the highway mode fueling kicks in. And that's on a 50 year old Camaro with the aerodynamics of a brick...lol.
Talking pure theoretical here. But was talking with a buddy about my vette (a 96 c4 lt1) While the 4l60e is alright. a 4L80E is better. But what was then brought up "imagine if you put the 10 speed in it" Which...what if. its a awesome trans that. wouldn't even notice the LT1 powering it. On that same coin. i also imagine its bigger in every, single way then the 4L60E. height, width, depth, WEIGHT, I imagine the trans tunnel would need MASSIVE surgery and so would the Cbeam. and ofc, completely new wiring setup, shifter linkage setup, etc. but would this even have any remote chance of fitting in the car? if not the 10 speed, 8L90-E? 6L80E???
Bad idea. The 96 is already so good and the OEM transmission serves it well. What makes the 4L80 so much better other than more gears when the 4L60 is already a great transmission? Couldn't' be the want for more MPG, since up to 28 MPG out of a 90's era sports car is pretty darned good. These aren't economy cars, but I'll take 25-28 MPG all day long - It's a bonus.
I see no advantage to adding more gears when 4 forward gears optimized for the Corvette of that era serves the duty just fine. Just more gears/more components to fail. Seems like a (potentially) large amount of money and effort for little to no noticeable gain. Let that theoretical dream go...
Last edited by Corvette-ZL1; 09-22-2023 at 10:30 AM.
You wouldn't swap in a 4L80/TH400 unless you were making monster torque, its beefy, thats the use case. If you want more gears you could talk to Gear Vendors and see what they can do for you.
You wouldn't swap in a 4L80/TH400 unless you were making monster torque, its beefy, thats the use case. If you want more gears you could talk to Gear Vendors and see what they can do for you.
But what is the advantage of adding gears? I understand there is a larger spread with only four forward gears, but I see no advantage to adding more. If it's for increased fuel economy, buy an economy car - I would argue that ANY gains would be insignificant when up to 28 MPG is pretty decent already. We don't drive 80's and 90's era Corvettes (and all Corvettes in general) for fuel economy.
As for performance, maybe you'd get a little better launch with a tighter gear spread, but for what? A couple of tenths or so per second, maybe? That's a lot of money to spend for such negligible gains. Such swaps/upgrades make no sense to me, when there are other less intrusive and less expensive modifications that could be made to increase performance.
If you want better performance, better economy (if you want to call it that), better gearing, better braking, etc etc, get a C5. They are even more outstanding value for the performance you get than the C4 these days.
Last edited by Corvette-ZL1; 09-22-2023 at 11:04 AM.
More gears = easier to stay in best power band. I would look at the 6 gears over another 4 gear trans.
For what end goal? The 4-speed transmission that the '96 was shipped with was optimized for the LT1s power band (and some fuel economy) during the development phase. It was a good balance of performance and fuel efficiency with the tech available at the time to accomplish that.
I'd like to see someone show me significant performance gains AT the STRIP or track - from ANYONE here proving that ONLY a transmission swap (and no other performance mods) made such a huge difference in performance to justify the cost/effort of such an upgrade. Let's see those HONEST before and after time slips to back that up. I doubt we'll see such info, because anyone doing this are likely doing other mods as well....
More than four forward gears was not a not a factor when this car was in the design phase - all it means is that you'll have to deal with more annoying auto shift cycles during normal usage. Who wants that?
I understand the utility of a 5 or 6 speed upgrade for a MANUAL C3 gen Corvette, but not for a C4 Corvette automatic.
Last edited by Corvette-ZL1; 09-22-2023 at 11:59 AM.
I don't go to the track, so I wasn't really interested in what my ET's would be with the additional gears.
For me it was just seat of the pants fun and having the extra gears to downshift into, as well as putting a gear between 1st and 2nd to eliminate that huge 1-2 rpm drop. To me that was worth the money and effort to install the GV.
Truth be told, I'm not using the GV all the time while I'm driving around town. But when I want to have a little fun with some spirited driving, having those extra gears is a hoot.
For those that say a performance gain would be negligible...New A10 cars are all faster by .5+ than manual versions. Back in the A4 days it was the opposite. So by that alone theoretically a 10spd should be. 5 faster than a 6spd LT1. Throw in a nice stall...another .5 reduction? Ever ridden in one?
Obvious obstacles to overcome...
Transmission controller. Can the stock PCM programming add gears and other tuning parameters?
So I've had three different transmissions in my 84 over the years. Obviously the 700r4 it came with. Then I swapped in a 4l60e and then a 4l80e. I have to say the 4l80e is far superior to the 4l60e as far as drivability. Now I also have 3.73 gears. With the 4l60e first gear was useless. The closer ratio of the 80e is much better on the street. A lot of the power loss from the 80e is if you use a factory converter. I'm using an FTI 9.5" with a 3600 rpm stall that was custom built for this car and how I drive it. That made all the difference. A factory converter would make the car sluggish.
Three big issues with a 6 or 10 speed automatic. One is the electronics. The transmissions themselves internally are fairly simple by comparison to a 4l60e. And that's because you have solenoids that control everything. Back when I was looking into a swap for mine there weren't a lot of options to run a 6l90. So I built my own 4l80e with a kit from CK Performance.
Problem two is availability. I can go to any self service salvage yard in my state and grab a reasonably low mileage 4l80e or 4l60e for $200. I can't do that with a 6 or a 10 speed. So if I destroy my transmission because I gave her a little too much nitrous I can just go get another one. I don't have to spend a ton of money and wait
Lastly is size. The 4l80e barely fits in the car. The C beam has to be chopped way shorter. But the tunnel is good as is. With a bigger 6 or 10 speed you would have a lot of fabrication to get it to fit. At that point it might not be worth it.
Like others said the gear vendors overdrive would get you there with way less work if you just had to have more than 4 gears. But I agree with the others who have said that in a street car that's an auto 4 gears is plenty. Swap the gears in the rear and get a nice converter. That will make a huge difference.
09-21-2023, 09:20 PM
How possible is a 10L90E swap?
