sprintamx

Well, I was able to turn one jacked rear wheel with almost no effort. Option codes are 220, 222 and 224. I presumed that means a factory lsd and traction control. Can I put eyes on the transmission itself to determine whether there's a factory lsd or not?

Ahmet, did you have any question whether the car has factory lsd? Ultimately, if it does have a lsd, it would appear to be shot.

Best option for repairing a factory lsd in a track car driven by someone who is far from race-ready? Simply replace/fix the factory package? Is there a core exchange process, or simply get the parts and go to work--not that I'm ready for that challenge yet.

Thanks again guys.

KobaltBlau

OK, Let's try to figure out what a reasonable amount of weight to take out of a street car is. I'm going to try to make a list of reasonable weight reductions for a streetable NA 996 C2. I'll be basing this on a 99 C2 but other 996 C2 should be similar.

I'm starting a list of potentials, and will edit as you guys suggest other things or we figure out or refine weights. If this gets good I'll move the content to the first post. Some of these things will be similar to the turbo thread but I think this car is different enough to make a separate list. Weights are savings.

- Non-sunroof car or roof skin replacement - cf roof 39lb per turbo thread
- Shell seats - around 45lb per mglobe, 75lb using recaro profi per V225 (seems high?)
- Spare tire and tools - 40lb per jasper
- lightweight battery - 32lb using Odyssey (pc680?) per mglobe
- all stereo components - ? dash, door, and rear speakers 24lb total per turbo thread
- all A/C components - 25lb per jasper
- rear seats - 22lb per jasper
- console delete - ? not much
- lightweight flywheel and clutch - 30lb per jasper
- lighter wheels - 36lb per V225 with OZ Alleggerita on C4S - wider. what about CCW or similar on C2?
- muffler bypass - 55lb per V225 (streetable?)
- cf or fg engine lid (maybe ducktail) / power tail delete - ?
- cf or fg hood - cf saves 28lb, fg saves 25 per turbo thread, not sure which mfr
- rear deck pad 10lb? per sprintamx
- interior carpet - 52lb per turbo thread (does this include deck pad?), same for C2? lightweight carpet 11lb per turbo thread, 41lb savings
- lighter mirrors - ?
- 2 piece rotors - ?
- 'remove front and rear 5mph crap' - sharkster - ?
- plastic rear quarters and rear window - ? streetable?

If you did everything I have weights for above, adding up:

39 + 45 + 40 + 32 + 24 + 25 + 22 + 30 + 36 + 55 + 28 + 41 = 417

Can that be right? 26XXlb street or street/track C2 plus any desired safety add-ons?

GTgears

Aaron,
Look in the 997 GT3 forum for a thread called "LSD Buster". It will tell you all that you need to know. Your diff is basically the same as a 996 GT3 diff.

Ahmet

A few comments on weight reduction;
After sliders and mounts are factored in, I can't imagine a 75lbs weight reduction from going to racing seats.
Shaving 32lbs from the battery seems hard to do as well. I remember running an off the shelf small battery (e38 740i secondary battery) that weighed around 35lbs if I remember correctly. Cheap street solution.
Lightweight flywheel and clutch probably won't add to 30lbs either, that seems optimistic, I'd say 10lbs maybe closer, but I haven't played with aftermarket flywheels on a C2.
I don't think the mufflers weigh much more than 50-60lbs, so taking out all of that weight seems implausible as well.

That said, the easy and fully reversible stuff I don't disagree with. Floor mats, spare, tools, etc. were out of my cars.

Aaron, the car has the code, I never had any reason to suspect it didn't work. Did you (before reading this thread )? Unless you're unhappy with something or are competitively racing, I would just leave it alone.

kjchristopher

These all seem very optimistic. (30# on a flywheel/clutch? Just how heavy is the stock unit?)

sprintamx

Wow! Top Gear Top Tip: remove your useless factory lsd and save 30 lbs.

Ahmet: There are enough things going on that a working lsd is not the highest factor; but it is relevant to know what is/is not working on your car. Since I've not spent any previous track time with a lsd, I'm not particularly missing it at this point.

ohdavey6286

I figured 50 or so from everything else mentioned and maybe another 50 from lightweight carpet etc. How much of a difference in acceleration and handling/braking is felt with the weight reduction?

jasper

I just saw a show on this. They took a stock Nissan Sentra, baselined it on a quarter mile and then progressively cut away more weight as they kept running the quarter.

The conventional racing wisdom they were trying to verify was that 100 lbs = 1/8 second on the quarter mile. At the end of their experiment they got closer to 0.25 seconds per 100 lbs.

They did not discuss nor can I attest to the validity of the scientific method they used. They showed only one baseline run for instance, and it's not clear if that was the best baseline run they made, or if it was just a single run. They had a pro driver there (a busty woman as it happens) so I assume she insisted on some common sense.

Hardback

bump for another lightweight 996 thread

Vdubjetta02

If you do the math calcs, I believe every 100 lbs shaved off the car equates to 11 hp.... So if you can get 200 pounds off your car and add a few small performance mods, these cars could really feel different

-I swapped my twist wheels for skinny 5 spoke wheels
-removed my spare tire
-removed my rear seats
-besides attacking the mufflers next, I'm not sure what to remove and keep it livable for summer road trips

dgmark

For what its worth, The 996 race car that I just finished came in at 2750,
This is with full roll cage, sunroof delete, full ac delete, gutted doors ,stock fenders doors hood, stock glass, stock duel mass flywheel, no fuel.

jumper5836

My 996tt is 3400 lbs with full fuel, it's stock with sports seats, all though that weight is with spare tire/tools and rear seats taken out.

5CHN3LL

The "gains" you see from weight reduction become less and less pronounced as speeds increase. If you've ever been in an Elise, it feels like a rocket from 0-60, but once you have to overcome increasing air resistance, the lack of power becomes progressively more obvious; the car that felt like a rocket a few moments ago feels like a slug as you get closer to top speed.

Less weight and more power make an even better combination.

oemexp

You can also go the other way with this. Take a full blown race car and add the weight back for the creature comforts you want to retain. My 04 996 GT3 RSR weighs in at 2370 pounds with no fuel. It has a heavier than EO fuel cell and pumps, brake parts, heavier large wheels and tires and it has a heavy electric power steering pump in the front trunk along with a full cage etc. Obviously, it's stripped otherwise. it may have been built with thin gauge steel also but I don't think so because many teams build competitive race cars from the street GT3 cars and they claim there is no difference in weight (but I've never confirmed this).

Slakker

It's beautiful! That weight is insanely light.