[Mackpipes]

I'm about to delve into a trans rebuild on the 930 and want to put a little more stank into it. What are the advantages or just doing a different R&P ratio vice a set of custom gears, or vise versa? Any feedback is welcome as long as it's blatantly sacrcastic.
I'll also be rebuilding the factory LSD. What percentage of slip should I use for mostly street driving with an occasional DE?

[Jazzbass]

Changing the R&P is the poor man's approach to re-gearing. By changing the gears, you have two advantages - first, you get to pick each ratio and move the gears closer together or further apart as necessary. This can be huge if you have a big drop between gears (e.g. 2nd and 3rd in a 964). Change the gears and eliminate the drop. Change the R&P and it's still there, just at a different RPM vs. speed.

Second, you maintain the factory R&P design, which can be a huge failure point if altered incorrectly. For example, early 915s have a 7:31 R&P. The problem with this design is that the force under acceleration of the pinion gear wants to push the ring right through the differential cover. The 8:31 helps alleviate this by changing the direction of the force applied to the ring gear (more in a downward direction, IIRC).

It comes down to $$$.

[BlackTalon]

What Jazz said. Man up and fork down the $$$ for the gears!

[forklift]

I was writing this up as Jazz posted, but yes, custom gears.

I have done a ton of searches on rennlist (sorry!) on this in case I ever have the $ for it (and PCA makes custom gearing legal in Prepared, which we should know on Thursday). This means my car is staying stock for awhile, but here is the best thread I read about R&P vs. Custom Gearing, although in the 993 forum/G50:

http://forums.rennlist.com/rennforum...ht=ring+pinion

I think I found most of the good info in the 993 forum, another good read:

http://forums.rennlist.com/rennforum...ht=speed+gears

You may already looked at the 930 forum, but this is one that came up (I haven't read it yet):

http://forums.rennlist.com/rennforum...ht=ring+pinion

If you have the $ then a custom box seems to be the way to go. I think you are supposed to find the top speed at the longest straight (VIR?) and then work backwards from there. If it were me, in my G50, I would do it a little differently, I would leave 3rd as is, raise 2nd and lower 4th and 5th. 5th is my car is completely useless and the lag between 2nd and 3rd is longer than it took me to write this. The 8:32 R&P for the G50 I have makes 2nd about useless, the redline is only 61.

If you have a 4 speed then you might just want to replace 4th? Brian Keith Smith was thinking about doing that and leaving the others alone.

I have attached a G50 6 vs. 5 speed chart that I found interesting.

[Mackpipes]

Originally Posted by BlackTalon

What Jazz said. Man up and fork down the $$$ for the gears!

This is the direction I was leaning toward. Who and where is the best resource for gears and ratio help. I've heard good things about Steven Casper over at Imagine Auto. Also there is Powerhaus for gearing. Anybody heard any good or bad about either of these?

Oh, and WTF you pu$$ies, what about blatant sarcasm do you not understand. I come to this board for a propper beating and all I get is good sound advice?!! Sheesh! Maybe I'll go post on Rennlist that I'm going to rebuild my own trans. That'll likely spark up a good beat down.

[forklift]

Originally Posted by Mackpipes

Maybe I'll go post on Rennlist that I'm going to rebuild my own trans. That'll likely spark up a good beat down.

LOL, I sent you the links to get there.

[forklift]

Originally Posted by Mackpipes

This is the direction I was leaning toward. Who and where is the best resource for gears and ratio help. I've heard good things about Steven Casper over at Imagine Auto. Also there is Powerhaus for gearing. Anybody heard any good or bad about either of these?

I would contact Chris Cervelli also. He is a gearbox wizard from what I have read/heard. I might send him mine for a quick stock rebuild in the offseason....w/ a steel 3rd gear synchro.

[Jazzbass]

Originally Posted by Mackpipes

Oh, and WTF you pu$$ies, what about blatant sarcasm do you not understand. I come to this board for a propper beating and all I get is good sound advice?!! Sheesh! Maybe I'll go post on Rennlist that I'm going to rebuild my own trans. That'll likely spark up a good beat down.

Sheesh... if you insist:

WTF, n00b? You've had the car - what? 6 mos? 5.5 of those you've been pounding sand overseas and *now* you can't live without custom gears? Why don't you take your candy ass onto the track in that thing instead of that pussy little 944 and then talk to us about needing custom gears. And a body shop to weld on a new rear quarter panel. And a celete to straighten the frame.

Better?

[Mackpipes]

Originally Posted by Jazzbass

Sheesh... if you insist:

WTF, n00b? You've had the car - what? 6 mos? 5.5 of those you've been pounding sand overseas and *now* you can't live without custom gears? Why don't you take your candy ass onto the track in that thing instead of that pussy little 944 and then talk to us about needing custom gears. And a body shop to weld on a new rear quarter panel. And a celete to straighten the frame.

Better?

Ahhhh. I knew I could count on you. Yes, much better.
Thank you sir, may I have another.

Maybe I'll just scrap the whole turbo thing and get a "rammer". I'm not sure I'm man enough though.

[Mackpipes]

Originally Posted by forklift

I would contact Chris Cervelli also. He is a gearbox wizard from what I have read/heard. I might send him mine for a quick stock rebuild in the offseason....w/ a steel 3rd gear synchro.

Jim, thanks for the links. I still haven't totally recovered from the ride along at VIR.