vanguard

I have been considering this idea ever since I learned it was possible on my 993. I did the research and found a shop that has experience in doing the conversion (roughly $1500 total in labor and parts sourced from FD). Now the $MM question, should I? I like the way the car drives now but I wonder if it could be better (tons of grip on long sweepers). I don’t experience the understeer that people commonly complain about. Since the 993 doesn’t have TC, I actually prefer the AWD system when I'm on the track. I experienced my share of tank slappers when the tires start to get greasy and could only imagine how it would be like with RWD. For the most part, the front wheels aren’t active unless VC senses slip in the rear wheels. So is it worth the endeavor? I recently decoupled the output shaft to the torque tube so essentially its RWD as of now. I just need to remove all the extras and change the shift linkage (roughly 90lbs in weight savings). What are the forum members feelings on this topic? I know a lot of veterans would say RWD is the only way to go for the track (that's how I felt too before I bought this car) but now I'm a convert. I would rather much rather spend that budget on toe links and semi solid mounts to tighten up the rear end. Your opinion is appreciated, thanks.

flatsixforme

I've done this to my 993 C4S and did it mainly for the weight savings as my VC was worn out anyway from track driving. If your car is setup well currently I can tell you that you'll have to re-align/balance the car as it changes things significanlty at the limit. And, remember you are taking weight out of the wrong place (middle and front) so throwing the natural distribution in the wrong direction. Would I do it again and am I happy I did it, absolutely; however, my car is mostly a track car and for my classing I was hurt by the extra weight. As far as driving experience differences, the front end feels a little more nimble and precise but the shifting I actually liked a little better with the AWD in place as the black torque tube offered a very solid mounting base.

For a DE car where time is not an issue, probably not worth it...spend the money on other suspension parts. For a TT car that you want to be competitive in its class, spend you money on both the conversion and suspension parts all at once, have it corner balanced and aligned once to maximize your alignment dollars.

darrendeguire

I'm not sure I would do anything to the AWD system if I were you. I would focus on skills and seat time, upgraded shocks (moton or jrz or whatever your favorite is) solid mounts for the motor and gearbox and take the rubber out of all the suspension points and you would be surprised how well your car will handle with a good corner balance and alignment. A welded in cage helps tighten up the chassis as well. I race my 993 turbo in J class and it has to stay in stock form so I race with AWD. With all of the upgrades I mentioned its very quick and handles very nice. I race mostly against 996 gt3's and the car is very competitive. They both have different strengths and it makes for fun racing.

If you street your car as well I'm sure the cage part is out of the question but the rest of the upgrades are money well spent, although driving on the street with them will be a little bit rougher.

GTgears

A 993 turbo has an LSD stock. A 993 C4 does not. This is going to impact how the two cars are going to different on track.

darrendeguire

I wasn't sure if he had C4 or TT? Also I'm not sure the TT's had a stock LSD or if that was an option. Mine didn't have one in it when I bought it 10 years ago. I can't imagine someone taking it out but who knows. It's going to need a replacement or rebuild soon and when it does it will be one of yours instead of the japanese lsd that I put in.

vanguard

Thanks for all the input. I have a C4S. As I mentioned, my car works great on the track. Its been extensively setup for the track (motons, gt2 uprights, camberplates, cage, etc). Its just a lot of naysayers think otherwise and made me have my doubts. I would have to realign and C/B which I'm not looking forward to. Plus my TT, front differential, and axles are perfectly fine, no leaks (hard to justify ripping it out).

Can any die hard rwd drivers chime in? Additional, how much of an improvement can I see with tarett toe links and semi solid mounts?

race911

I think we answered this over on the 993 Forum. I'm not sure how many guys drive two of their own 993s same day on track, pretty much within the window that any of us amateurs will achieve. Of course the RWD car is extremely developed, and the 4S is near stock. But I don't give a rat's *** about the AWD on the 4S.

darrendeguire

I think race911 pretty much nails it with the amateur comment. Solid mounts and all the other upgrades you have work well when they are all combined and dialed in. Reality is most of us here that race are amateurs and our weak link is our own natural talents and lack of seat time and perhaps some good coaching. Put a pro driver in my car and he's going to find ways to overcome the awd understeer better than I do and he'll do it consistently lap after lap. I'll never be as good. Point is I doubt I would pick up much time (not including the weight factor) by dropping the awd on my car. I have many other areas I can still improve on to get quicker and also better at my race craft. Awd as an issue is not even on my list. Just my two cents.

Acropora

AWD can save your a** when the rear steps out ime. The car feels a lot less "heavy" steering with it removed, much more lively up front, and so more fun to drive. A bit more risky though if you're going 10/10 on track

swftiii

I had a 97 C4S for many years, but decided to get rid of it as it just isn't the best platform for club racing due to the aero and weight penalties.

But, why are you considering the change? What are you looking to accomplish?

If you are a DE driver and not a club racer, then drive it as it is and enjoy the extra traction when needed. If you are looking to go racing, then you have a harder decision to make.

-Skip

Serge944

If you have to ask the answer is no. It will change the dynamics substantially, so if you your heart isn't burning to do it, don't bother.

spare tire

With AWD you can preted to be Senna on the rainy days.

GTgears

Sorry to bump this but I figured it was good information to add in case someone went searching at a later date. The G64/51 used in the 993 Turbo got a 20/80 LSD along with ABD, an early variant of traction control.

Those diffs used carbon clutches that had a 25-30k mi lifespan when driven hard. The only reason I can think of someone removing it was because throwing in an open diff was cheaper than rebuilding the worn out LSD or they were planning to put it into some other car they were going to buy in the future after they sold off the 993 Turbo. Maybe they had a track car and didn't track the turbo and just swapped diffs between the two vehicles.

race911

Saw this thread got revived, and the above was posted since I last looked. Care to explain?

On Monday I slammed out a couple of 1:53 laps as a guest in a GTL car (3rd session, about my 7th and 8th laps at speed). Hadn't been to Thunderhill for a year. I'm waiting for data, but I'll compare it to both my faux RS and 4S I've mentioned previously to see if there's any difference between the three cars.

DM993tt

I did this to my TT on jackstands over a weekend in my garage. I am a PCA instructor, my TT has a guarg LSD and ERP monoballs and GT2 Evor uprights and all the other suspension bits. I did not touch allignment after taking out the shaft VC and Axles. I did use Fister DiPietro to get all the right parts and they are an amazing resource.

The car is a bit more tail happy on street tires, but with Hoosiers R6's 315r 275f, the car behaves well at the limit, the lack of AWD is really noticed in the reduced weight, (125lbs or so) and the lighter steering feel. Grip really isnt an issue. If you get to a point where the tail is coming around on you AWD isnt going to pull you out of a mess I've spun with and without AWD. I did wait until after 10years of DE and reaching the instructor level before I pulled the AWD. I honestly think until you get to a point where you are frequently finding the limits of adhesion, you may not even notice the difference. I think the only thing I may have lost is resale value - the rest is all gain.

One very important thing removing the AWD enables is...