964speed

My 1st gear synco is grinding and i am considering a rebuild.

I've heard that shortening the gear ratios would make the car fell like you added 100hp.

Its expensive, any advise on this upgrade? is it worth money?

Dave 86 930 Fl

Another option is to change out the R&P ... I'm going through the decision process myself right now, not sure which way I'll go yet.

Last930

I drove an early 930 with thr R&P shortened and it made a pretty big difference in acceleration, at the expense of higher rpm on the hwy. To the owner it was worth it because he tracked the car often; to me it wasn't worth the $ when I had my trans gone through recently. Try to find a car with short gears and see for yourself before doing - it's a lot of $.

964speed

I heard its the best bang for the buck performance wise.

But depending how crazy you get it could range from 5k -9k

each gear is a 1k and all the parts and labor.

Most of the prices I gotten are about 6k

964speed

How much higher is the car reving...

MUSSBERGER

My race car had a 7.31 in it till some teeth broke off. Went back to the more robust 8.31. Just throwing that out there.

GTgears

Last time I checked, those were 915 ring and pinion ratios. On the 930 gearbox, the short ratio ring and pinion is an 8:41 and it's just as bulletproof a configuration as stock.

964speed

aren't stock 930's R/P 9/31??

8/31 is still an upgrade, right? Performance wise that is...

TT Surgeon

Bobby at MMS in Roslyn can do the rebuild.

MUSSBERGER

Last time I checked my race car was an SC.

GTgears

Right, and how does anything related to the 915 gearbox in your 911SC cross over to the 930? It doesn't. Not trying to be sh!tty with you, but it's just not relevant. Your post suggests that going to a shorter ring and pinion might not be a good idea because it's weaker. That's great advice for a person with a 915 in their car. Not really applicable to a 930 owner.

964speed,
Stock ring and pinion in the 930 is 9:38. Historically, the two alternative shorter ring and pinions for the 930 4spd have been an 8:39 and an 8:41.

964speed

Thank you!

MUSSBERGER

So you are saying an 8.41 is just as strong as the Stock R&P? That's good info. The point I was trying to make was when you see a 7.31 next to an 8.31 the physical difference is quite noticable.

Any chance you could show us the two 930 R&Ps side by side?

TT Surgeon

Seems to me that if the 930 4 spd has a 9:31 rp, switching to a 8:41 is going to make the car less responsive, no?

MUSSBERGER

I'm risking a beat down here. In my car between the cams, clutch, and the 17"
Fake Fuchs it would inhance the street driveability of the car. My car can be a bitch to get rolling from an uphill start.