993RS

As most of you know, the U.S. and Swiss 993 versions were equipped with longer gear ratios (2nd thru 5th) to meet "noise" and fuel consumptions issues and please the bureaucrats. At some point (forget if it was 1997) all 993's got the longer ratios.

To recapitulate:

Gear US/Swiss Rest of the World % Taller
______(G50/20)______(G50/21)________
1.......3.818.............3.818....................0
2.......2.048.............2.150....................5
3.......1.407.............1.560....................11
4.......1.118.............1.242....................11
5....... 0.962.............1.027....................6.7
6........0.775.............0.820....................6


Now since I am in my new re-incarnation as a Rennlist member, prinicipally against mods , I resent the negative mod on performance that has been done to my car, and want to restore it to original specs (I have managed to convince myself of what I am saying BTW ).

To do so, I have basically three options:

1) buy a new gear box with old RoW specs
2) buy a used gear box (from a 993 which had an accident)
3) have the gearbox dismantled and insert the new gears

Evaluation:
1) Nope: too expensive
2) Too risky (no way of knowing what shape it is in)

Which leaves me with three. Not cheap, but worth it IMO. I am going to save a bit on the costs by only having the gear ratios 2 thru 5 changed.

My Porsche mechanic is on vacation next week, but he will email me an offer in about 10 days time, listing all the parts needed, along with a price estimate.

If you guys/gals are interested, I will post this information on this thread.

BTW: As long as they are dismantling the transmission, he suggested they check the clutch and revise it, if needed.

993RS

Forgot to add (to spell it out clearly): 11% taller means you feel as if you had about that much less power in the corresponding gear at any given rev... or, stated simply, in third gear, for example, you feel as if you had about 30 hp more....

csertich

I would definitely be interested in hearing more about this as it progresses.

Thanks! Sounds like a great upgrade.

chuck

993RS

Chuck,
Actually I consider it a "retrograde"...

poorb0yw

I suggest looking into a Tilton carbon/carbon multidisc clutch and mating it to a GT3RS flywheel. The clutch will easily hold 900 ft-lbs of torque and has great wear characteristics (grabs better the hotter it gets). As for the GT3 flywheel its only 8 lbs compared to the much heavier 993 RS unit.

You can just look at this as a newer technology "revision".

GratefulJED

Isn't number 1 going to be cheap compared with number 3? Are you doing some custom gearing or just pre 97 euro? I am doing the retrograde right now and can't wait for the end result.

Woops - did'nt read clearly - number one said new gearbox - probably more expensive than number 3...

STLPCA

Phil
Since you've been "away," you might have missed this extraordinary link to an interactive gearbox comparison put together by a Rennlister (Note: only works w/Internet Explorer).

http://members.rennlist.com/david_t/gears.htm

993RS

I was told 1) was about twice as expensive as 3)

993RS

Thanks Dan. Corrected it. Great link!

STLPCA

You're welcome.

solsrch

I'm not sure if you need more "yes" vote but YES. I'd like to get the details too. The synchros on the lower gears were in sad shape when I got my 930. I had priced out some replacement work and it wasn't that bad. Now that I'm 993 oriented, a couple folks I know have gone to the G21, an expensive route. I'd like to know the alternatives. Thanks.

dave morris

Phil,
I'd be interested, too. What would adding steel syncros in 2nd, 3rd and maybe 4th add to the cost do you think?
Dave
'97 C2 coupe
'84 911 coupe

chris walrod

I think its safe to say that all of us 993 nuts either are planning to do this....revision....or, have already done so...lucky ba$stards

Best route may be to buy another gearbox (G50(64)-21) and stick it in, so to speak. I think this would be the cheaper route, but, this is only if you find a good one that doesn't require opening up. The plus side to this is that you'll have another complete gbx to sell, or keep when you sell your 993..

Opening up your gbx to swap gears can be really expensive when you get the 'while we are in here'itis'' This is when it gets out of hand in most cases. You want it done right at that point..

There is always pros and cons to which way you go with regearing transmission's..

GrantG

If you have your gearbox opened up and regeared, there are several distinct advantages:

1. All new gear parts, but also good time to replace bearings, synchros, etc. for a very long-lasting gearbox.

2. You can choose even better gearing than the RoW gearbox. Although the RoW one is far better than the US gearing, it is still too tall for aggressive driving. If you are willing to give up a bit of the high-speed capability (do we really need to go 171mph?), you can get a much more closely spaced set of ratios that will really wake up the 993. I was considering this mod with Steve at Rennsport Systems and he recommended making the current 5th gear the 6th gear and the current 3rd gear 4th gear,leaving 1st alone and regearing 2, 3, and 5 (I hope I'm remembering right - ask Steve) so the resulting gear set is much more closely spaced. Should be a big improvement over RoW...

3. Good time to insert a better differential (either clutch type LSD that is far better than the optional #220 or a torque biasing diff).

Unfortunately, this isn't cheap, so I wouldn't do it unless I knew I was going to keep the car for a long time...

solsrch

I could definitely live with the current 5th as 6th. This sounds like an course of action. Much more usuable in regular life. Do you remember any price range from Steve? I'm sure you'd get a great product.