AX993

Bob (viperbob), What does the 996 cup LSD cost ? and does it interchange with a stock C2 LSD (the ABD one that my car came with)? What kind of ratio does it have. Finally, can a home mech do this themselves , or is this a specialist type thing. I'm assuming that with over 60,000 miles my stock one is worn out.

Tom W

Glen, having just gone through it (or still going through it) your math isn't too bad. You need to add the cost of dropping the engine and transmission, consider all the "while you are in there" costs (will you really just drop and re-install or will you remove and clean/powder coat the tin, replace the engine and transmission mounts, change the plugs and wires, check the power steering, etc).

I've had my old transmission for sale for 4 months without any takers yet at $3.5k (yes, it is a 5-speed instead of your 6-speed).

I'm getting questions but no buyers for my /32 LSD at $1500 (and at about $360 to install, cheaper than the $2500-$3500 you are estimating).

Mark in Baltimore

Glen,

If you're moving along the track pipe as quickly as I think you are, you may end up club racing your 993. If you put in a short box, you'll be moved right to the GT classes. I don't think a stock 993 that weighs 2800 lbs (my best guess at how much weight you can remove without havng to go to lexan glass, fiberglass hood, etc.) is going to be very competitive in GT. My advice is to not do the short box, unless you know with 100% certainty that you won't be racing your car.

Tom,

I'm amazed that no one has jumped on it yet. If I didn't have my Guards, I would have scooped it up in a heartbeat. Good luck.

ninjabones

Mark:

I was just reading through the PCA rule book, wouldn't a regear simply move you to a "prepared" status, meaning jumping one class to H? Wouldn't a 993 (with chip, brakes, and regear) be competitive here? I think a guy in my club, Bob Terjian (?sp) is competitive in this class.

The concept of racing my 993 has entered my mind, but it's going to take a long time to develop the skills for me to get there. I certainly don't want to exclude the possibility with my 993, but I may end up deciding to race a different car if my interests continue in that direction (e.g spec miata, or maybe even spec boxster if that catches on on the East coast). Anyway, I'm just tossing around ideas. Hearing everyone's perspective is helpful.

Tom:

My labor estimates may be a bit different than yours. My shop will likely charge me a full day of labor. I have some other leads on LSDs (Guard will rebuild a worn-out motorsport one for $450-$750 with Guard internals to my lockup preferences). Also, a new motorsport LSD direct from Porsche (through Sunset) is $1680 (which includes a two-year warranty). Based on all of this information, I made an offer for yours that still stands. Let me know.

Glen

viperbob

Last Motosports diff I got was around $1600 IIRC. All these diffs work in G50ish boxes (and even the standard 996 type). And yes generally anymore the stock 993 LSDs (the few that had them) are generally dead with 25k miles.

You do NOT want to try this yourself. You do need some very specialized pieces to set the proper position of the diff in the transmission case. If it is not perfect, then you can get some serious whine or worse a broken ring and pinion.

Mark in Baltimore

Glen,

Re-gearing will move you to GT, trust me. If you add a chip, big reds and a ring and pinion, you will move from G to H. You are allowed to re-gear if, and only if, an R&P is not available for the car (not true in the case of the 993); then, you can re-gear if the resulting gear ratios are equal to an R&P change. Since an R&P is available for the 993, you cannot re-gear and remain in a stock class.

Bob Turgeon is the driver in RTR and, yes, he's plenty quick. He was racing in G (old D class), though, so I'm not sure how competitive his car will be in H (old C class) with brakes, chip and a still pork 2944 weight.

ninjabones

Thanks Mark... I reread the rule book and you are definitely correct. Thanks.... you just saved me $6,000. Now where am I going to spend that money? (typically Rennlist rationalization).

I also read the section regarding LSD. Looks like you can go aftermarket (ie., Guard) as long as you stay with the ZF type (meaning no toque biased units like Quiaffe). It also states that you have to stay with lock-up rates available with the stock unit. Does that mean that you have to stick with either 20/40 or 40/65? Did porsche supply a 50/80 with any of the 993 cars? I also imagine that there would be no-way for anyone to really know what lock-up rates you had setup in your car, so the question may be pointless.

Last question... the rules state that you can remove panels that are required for the installation of a roll cage. It also states that you can not remove any carpeting or upholstery that is glued. Are they pretty strict about this? Can you get away with stripping the interior under the "guise" of necessity for roll-cage installation, or are their components that have to remain (rear shelf, sound deadening, etc)? Can you strip and then replace with RS carpetting? What have most guys done with regard to this?

CornerCarver

I contacted Mr. Guard and he indicated they are close to completing a new
"Club" version diff. Has same internals as there GT2 lsd, but the housing will be made with an easier to machine billet material that will lower the price possibly less than Porsche Motorsports lsd. This is a great alternative to the costly GT2 lsd and should be more robust and less expensive than the motorsports lsd. I am waiting for more information and final pricing.

Mark in Baltimore

Glen,

The new 2008 rules state that any LSD can be used. I don't think it's limited to clutch-types. A Quaife, which I'm fairly certain is allowed, would offer a performance disadvantage over a clutch-type since there is not braking lock-up. The only limitation to diffs is that you can't run a locker diff (spool-type, 100% locked). As such, I don't think the lock-up matters for CR rules. You are correct in noting that the scruts will never be able to tell what lock-up rates you have.

They are strict about the carpeting, so, no, you can't remove the rear shelf, side panels under the rear windows, rear carpeting, etc. You can remove the door panels to facilitate installation of cage door bars. The headliner can go, too. RS carpeting is allowed, as is removal of sound deadening material.

ninjabones

Thanks Mark. Al, interesting info from Guard. I spoke with them on the phone yesterday and they didn't mention anything about this to me.

CornerCarver

Maybe I was supposed to keep that to myself

JasonAndreas

The stock heat exchangers on your 964 make this a PITA to do with the transmission attached to the engine (you have to pull studs). I've done it but if/when the next time comes the engine is coming out.

AX993

Bob, Thanks for answering my Noob questions !
Glenn