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Thu Aug 17, 2006 10:49 am

I was wondering roughly how much hp a stock 914 5speed tranny will hold up to. Im running a 300hp type 1 engine and mating it to the 914 transmission.

Thanks

Thu Aug 17, 2006 11:32 am

Go easy on first gear and watch the teeth on the flywheel for wear if you are running really high compression and you'll be ok.

Thu Aug 17, 2006 4:46 pm

and how much torque?? high torque burnout will toast the ring and pinion eventually but it will last quite awhile.

Fri Aug 18, 2006 9:30 am

150 hp is roughly the limit for the 914. In addition to what has been mentioned, the "synchro teeth" are much weaker in the 914 than in a VW trans.

Fri Aug 18, 2006 11:54 am

ReallY? all kinds of guys run the 901's with 2.3l 180hp fours, 3.2, 3.6l sixes, 350 V8's etc motors running lots of hp.

Now if you are talking a drag car, forget the 901.

Fri Aug 18, 2006 6:44 pm

Oh, yes .... you can get away with much higher than 150 horsepower for a time, but when max horsepower is actually used (high-speed track use), reliability goes down dramatically (when coupled to greater than 150-160 hp). Even the 915 is on the edge with a 3.6, and those V8 street guys are always babying their transmissions.

Fri Aug 18, 2006 7:19 pm

From Steve Weiner (Rennsport Systems) website:

"The first transmission designed for the 911 was called the 901 transmission. This unit was used in different variations in the 911, 912, 914 and 914/6. The early versions used sand-cast aluminum cases and the later ones used pressure-cast magnesium. These were 4 and 5 speed transmissions with a torque input rating of 138 lb/ft, later uprated to 148 lb/ft in 1969. The fact these transmissions have been used with engines producing more than 230 lb/ft of torque, albeit with shorter lifespans (measured in broken gear teeth), speaks volumes about the basic design."

Sat Aug 19, 2006 7:16 am

Well from practical experiences, the 901 is good upto 300hp coupled to V8's, hipo sixes etc. given that first gear is locked out or not used to do burnouts.

They fail at the pinion gear with high torque motors as it will shear the teeth off the pinion.

Its a very strong tranny except for 1st gear which hangs off the back and is weak. I haven't seen alot of gears (2nd, 3rd, 4th or 5th) being sheared or failed in a 901 other than 1st/reverse and the pinion.

A solution to strenghten the mag cases is to use a aluminum intermediate plate and for racing to setup a oil cooler with a spray bar. Really works well on Race Cars. I know several cars/guys running 3.0 or 3.2L sixes that race and don't "baby" their trannys and have run them for years but for track use you should install the oil cooler/spray bar setup.

The original question was " I have a 300hp type 1 engine...." I doubt this will toast a 901 tranny.