Predator

Hey guys, anyone know what the factory rates the stock 951 tranny as far as capable hp? I'm getting about 125 hp next week with new heads, manifold, cam, rockers, etc. and wonder if the tranny will hold up. My sources say it will hold up to 500 hp? Any knowledge of heavy duty CV joints and axles? Thanks

iloveporsches

I don't know if the guys who run 400-500+ rwhp have upgraded their tranny, but I've never heard of anyone doing that.

billybones

most Good mechanical things are built to handle 125% capacity. As a norm. Thus long life expectancy. They tell you 10, It is good to 12.5. at 12.5 though you are running at the max. thus shorten the projected life expectance. due to the over burden. you get 7.5. 951 tranny out of the factory is what? JMHO.. If it fails then what? I am looking at this conversion and would be interested in what you find..

PorscheG96

Are you thinking 125 horse on top of what your engine is making now with those items? No chance, maybe 20 horsepower. Horsepower isn't what breaks a tranny anyway, it's torque. You'll be making 100 lb-ft LESS torque than a stock 944 turbo and 951's with twice the horsepower they came with from the factory are running all over the place using a stock tranny, so you have nothing to worry about.

pete944

</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">Originally posted by PorscheG96:
<strong>Are you thinking 125 horse on top of what your engine is making now with those items? No chance, maybe 20 horsepower. Horsepower isn't what breaks a tranny anyway, it's torque. You'll be making 100 lb-ft LESS torque than a stock 944 turbo and 951's with twice the horsepower they came with from the factory are running all over the place using a stock tranny, so you have nothing to worry about.</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">He's running an LT1 small block. A gain of 125hp may be a little conservative.

PorscheG96

</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">Originally posted by 944pete:
<strong>He's running an LT1 small block. A gain of 125hp may be a little conservative.</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">Hello! Didn't see that. <img border="0" alt="[hiha]" title="" src="graemlins/roflmao.gif" />

It depends on how you drive the car then...drag race starts with 250 lb-ft torque at the wheels will eventually break it. John Anderson drove his 951 with 515 lb-ft at the wheels and didn't have any problems. I doubt he ever dumped the clutch with it, though.

Predator

Thanks for the input, but still trying to find any info that the factory put out on these trannys as far as torque capacity.

Sami951

What kind of transmissions did the factory use in 968 Turbo RS models? That car probably had quite a bit of torque...

There appears to be some upgraded CV joints available at <a href="http://www.lindseyracing.com/944sus12.htm" target="_blank">Lindsey Racing</a> (was just browsing around and found that, no clue if they're good or not)

Then there is Powerhaus II, they probably know a lot about these trannys. Again, I've only been browsing their site, never done business with them.. <a href="http://www.phii.net" target="_blank">http://www.phii.net</a>

And like already mentioned, a big issue is how you use the car... drag launches will kill the box eventually even if you didn't have huge amounts of power .. so be careful!

<img border="0" alt="[bigbye]" title="" src="graemlins/xyxwave.gif" />

RSflared72e

I knew a guy running a modified Chevy 400 cid engine in his 944, with a 951 transaxle. Made somewhere north of 450 hp. The limiting factor there was the rear axle shafts/CV joints - he had a stack of them with stripped splines....the transaxle never gave him problems.

It was cool as hell watching him do block-long burnouts, making all kinds of engine noises a 944 was never intended to make...YMMV Al

Legoland951

I think the best way is to find another tranny just in case if this one comes apart. I think it will cost much less than trying to find a turbo S tranny with hardened first and second gear. I would imagine the cv will come apart before anything else unless misshifting is involved. Does renegade motor have this information and reliability of the turbo tranny used with a v8?