Is it possible to mate an ls1 engine or an lt era engine with the C8 Transaxle. It would go into a mid engine kit car like the ultima/SLC. Is this remotely possible given the computers running the trans? I figured you guys would be the best community to ask!
The goal is to have paddle shifters for the kit car. I dont know of any other transmissions that would have paddle shifters. Side note, unreliability of the c8 trans is an issue.

 

I know there have been a few "breakthroughs" in the past few months into unlocking and tuning the C8 PCMs, so this is unlikely to remain "virtually impossible" forever.

At this time, if you want something you can drive in a few months, I'd go a different direction.

The Tremec TR8090 from a C8 isn't an "automatic transmission" that operates like a 6L80E or 8L90Ee. The transmission designation looks more like a Tremec manual transmission, and it operates internally like two separate manual transmissions, with the PCM controlling two separate clutches, one for the even gear and one for the od gears. The PCM also controls the shift forks electronically. But there's shift forks, synchronizers (or dog rings) and clutch(es), just like a manual transmission. There's no way you'll get a LS1 or even LT1/LT4 PCM designed for either an automatic or a manual transmission to operate the Tremec TR8090. You'd need the C8 PCM, and I don't know if it could be used to control an LT1/LT4, or an LS3 or any other older LS engine. The C8 PCM is designed to run a LT6 engine, and that engine is significantly different from the older Gen III and Gen IV engines.

If you could get a complete C8 (possibly a wreck with severe front end damage), you could use the entire powertrain with the C8 PCM.

Here's another thought. There are paddle shifter kits for both the 6L80E (a rock solid unit that's been around for about 15 years), and for the 8L90E (slightly more problematic, especially in the Corvettes. Both of those transmissions were used in Corvettes, the 6L80E in both C6 and the first year of the C7 IIRC, and the 8L90E was in the later C7s.

The Corvette versions had the differential directly attached and operated as a "transaxle" with a torque tube leading to the torque converter on the back of the engine. Camaro, Cadillac CTS/CT5 versions and the ones for the trucks were attached to the engines and ran a conventional drive shaft back to the diff. I'm just spitballing here, but I bet it's possible (though possibly not very easy) to use the bell housing and torque converter from a Camaro or a Pickup Truck on the front of a C6 or C7 Corvette transaxle assembly, and bolt the LS/LT engine to that and create a mid engine powertrain. You'd be in uncharted territory there, but you'd be working with parts that have been around for many years, and parts that people know a lot more about. You could use the PCM from a Camaro, a Corvette, or even a Pickup Truck to run an appropriately selected and matched Gen IV engine and the automatic transmission.

Another possibility is to get a sequential shifter setup for the manual 7 speed Tremec in the C7 Corvettes and later Camaros. That definitely exists. You'd have 3 pedals that way, but a cool "sequential shifter" stick in the console instead of the boring old H pattern.

And I know there's rev matching firmware available for a paddle shifted C7 (or even for a manual or sequential shift manual C7) that will make the shifts quick and precise on either an auto or a manual setup.

 

I feel like the only 2 viable options for a genuine transaxle (opposed to the corvettes "transaxle") would be 1. Get a manual H pattern transaxle, and use pnuematic shifters to make it sequencial. Or 2. Spend literally 25,000 dollars on the transmission from albine thats exactly what im looking for.

The only issue from albine is that its a dog box/gear transmission, and seeing as it would be used on the street i dont think thats a great idea. There is supposedly a mesh box version of it (i assume for a ludicrous price given the dog box crazy price). As for finding pnuematics to make it a fake sequencial, its doable but again completely uncharted territory for a genuine midenging layout.

I know of one guy using the transaxle out of the c8 for his midengine layout, however, he is literally ripping the guts out of a crashed c8 to put into his project. While this is realistically the best way to achieve the DCT/Sequencial setup with a transaxle. Im just trying to find the most cost effective way about it.

I really appreciate the reply, if you have any input on if the pnuematic driven h pattern manual transaxle would work best that would also be greatly appreciated.

 

Honestly, I don't know that I can help you. Nobody uses pneumatic actuators to make a "sequential shift manual" any more.

The drum type sequential shifter has been used extensively in racing for a couple of decades, although it dates back to the 1940s or 1950s for automotive gearboxes, and back into the early 20th century for motorcycle gearboxes.

The upgrades for the manual Tremec gearboxes replace the shifter mechanism with a sequencing drum. The better upgrades either include or require replacing the synchronizers with dog rings because that's needed for the shifts to take place quickly enough.

I know two people who have sequential shifters on their manual transmissions in their corvettes. One had it done over 15 years ago, and still has the car. His was done at a place in Marietta GA, and they also refitted his T56 with dog rings in place of the synchronizers. His C5Z06 has been trouble free (in the transmission) ever since. He still drives it quite a bit. The other one I know had an upgrade/retrofit done to his C7, and that one only changed out the shifter itself. He had a bunch of problems until he finally bit the bullet and had the synchronizers swapped out and dog rings swapped in.

Even Nascar is using a sequential shift, dog ring gearbox in their newest generation cars.

But from looking online, it looks like both the Ultima cars and the SL-C cars are designed for the Porsche gearboxes. You might be able to fit the entire C8 drive train in the SL-C, but you'd need just about an entire donor car for that (at a minimum, you need the engine, transaxle and probably most of the electronics from the entire car).

 

So basically the three options are, spend 20k minimum for the albine trans, possibly upgrade the porcshe trans to have sequencial internals or rip the entire drivetrain out of a c8. I guess all options will be the deep pocket approach.

I really appreciate your input! Thank you

 

As already stated...
The C8 Transmission is not an Automatic with a Torque Converter.

It is essentially an Electronically operated (Dual Clutch) Manual Transmission, with NO Clutch pedal or Manual Shifter.

Next; the C8 does not use a Gen-V SBC Engine... it is a Cadillac Engine with a totally different Bell-Housing Shape and Bolt-Pattern.
So it is not compatible with any Generation SBC Engine.

If you want Paddle-Shifters...
They can be added to many Transmissions; including the 4L60E Family and the 6L80E Family.