4G64 944

At what power level are you guys starting to break/rebuild your transmissions and rears. I am looking for a 944 with a blown motor for a swap and I am curious as to how stout the driveline is with these cars.

josephsc

Just for a point of reference, I recently spoke to a couple of people who has swapped a 968 engine into a 944 NA w/o changing the transmission. They did not report any drivetrain problems. On the other hand, Porsche strengthed the tranny for the 951 (and made the gears taller). I've heard rumors of Chevy engines swaps routinely destroying the transmission (but only rumors). What are you planning on doing?

4G64 944

Pending measurement and finding a car (I have my eye one with fender damage, but haven't gotten in touch with the seller yet). I plan to use the 2.4L Mitsubhishi engine turbocharged. I have a 99 Eclipse gsx now and with about 400hp I'm on my 3rd tranny rebuild, so I am fishing for swap ideas, I would most likely use a v8 sytle tranny like a tremec, but if the porsches could handle 450ft/lbs of torque I would consider it as well. This will most likely be a pretty long term project since it's pretty involved. I know most will say swap in or outright buy a 951, but the aftermarket is really pricey for porsche parts, and I already have the 2.4 with forged rods/pistons and turbo setup.

Robby

I would LOVE to hear more about this, as I've often wondered where the real line is myself- I'm also thinking that a lot of people who have lots of mods aren't REALLY making the power they THINK & THAT is having an affect on their trannys- thereby helping them to last longer- I DO know that the 968 tranny is a much beefier unit than a 951 S & the 951 S is slightly stronger than the regular 951, which is stronger than the others- not sure where the S2 fits in... Problem w/the 968 is that shi**y gearing- I JUST found out that you can't even get a dif FD ratio for it- custom gears are a LOT more than I was once quoted (all from Powerhaus II BTW) & there are only a few avaiable- most of what they have are shorter gears which would RUIN the car for street drving & most tracks IMO... They once quoted me $300/ea for 968 taller gears, but, are saying now that they are ~$900/ea- since you'd need to replace at least 4 of them, you'd be out quite a bit & THAT's assuming you could even find them- I'd LOVE to find a place that COULD re-gear these cars a little...

josephsc

There are quite a few 951's around the list that are producing that kind of power -- you may want to redirect your question to the Turbo guys and see if they have kept the stock tranny and how they are holding up. I would guess many of them are still running the stock tranny.

Robby -- I concur with your feelings on the 968 gears. And what's with the 4.5th gear instead of a taller 6th gear? I suspect this is one of the reasons why people aren't rushing to swap in 968 tranny with the engine swap.

W88951

AFAIK the only difference between the Turbo and Turbo S transmission is a Hardened first gear.

Dave

How the heck would you put a v8 style trans in a 944 and still be able to call it "cost effective". You could by a perfect 951 and a LOT of upgrades for the cost of the engine swap and tranny swap and floor pan swap and pedals and rear and new rear suspension and.....

4G64 944

$1000 for the tranny $500 for an adapter plate, a custom driveshaft and alot of sweat. I don't really want to argue the valitidy of the project, I'm just curious about how much the stock drivetrain can handle.

Scootin159

Problem isn't so much of how you'll get the transmission to mate up with the motor/axles....but where you're going to put it. Our tranny's are in the back. You couldn't even really just put a transmission/rear diff setup in the back because the transmission is actually behind the rear axle, with the output shaft coming forward into the diff.

Robby

Yeah, I hate the top gears the most- I talked to Powerhaus II a long time ago about it- was told they could do custom gears for $300ea- just talked w/them today & they said they would be $900- looks like there's really no way out, unfortunately- I want to get an early 944NA 5th, OR, better yet, an S2 5th to put into my 951- I'm not sure if any of these would fit into a 968- if so, maybe you could do that. W/the stock 951 FD, etc, the NA 5th redlines ~191 & the S2 ~180... I think the S2 would be perfect to go w/the first 4 951 gears...a nice comprimise b/t the short stock & the really tall 944NA...

RSflared72e

I knew a fellow with a Chevy 383 in his 944, using a 951 trans, making somewhere north of 400 hp. The weak point seemed to be the rear drive axle splines/CV joints. He had a stack of these he had stripped out from doing burnouts, but no tranny failures. I think he had suffered an earllier failure using a NA trans, not sure.

4G64 944

Ahh that makes sense. I have seen a couple small block 944's at the local track but they were full drag cars. I'm going to have to get a look undnerath and see how this whole setup works. Am I understanding this right, the clutch and flywheel are attached to the block, but a long output shaft runs to the back into the trans which also houses the diff and acts as the traditional "drive shaft"? I'm also assuming this was the only way to get the 50/50 balance.

4G64 944

Ok I see now, I actually looked this up now that you mentioned that, and here are diagrams I found:

http://www.9ss1.dk/porsche944/dele/pic017.gif

http://www.porschemania.it/951/tecnica.htm

JustinL

The weak point is definetly the C.V. joints. The P.O. replaced mine with some from an N/A 944 and I've broken two of them over the summer. Granted that I was working it pretty hard over bumps so I've learned a thing or two about accelerating on a rough road.

Justin

Predator

I'm currently running the LT-4 conversion, using all GM parts, roller cam and rockers, 2.02 valve heads, manifold, hedders, and BBK 52mm throtlebody. GM says 425 hp and 415 Ft lbs. from 5.7 litres. Car runs mid-4 second 0-60, and 9.6 0-100. So far, no problems with 951 tranny, but I,too, think the CV joints are the weak link. So far, can't find anything stronger than stock ones.