Lightweight street or street/track 996 builds out there?

Hello, I haven't posted here much as I'm more of an 80's 911 guy, so please bear with me if I do something silly. I'm looking for examples of 996 cars that have been significantly lightened or re-built as lightweights, but not full time track cars. There was a 9ff built 3.4 911 in Excellence years ago, I believe they quoted curb weight in the 28XX range, but I no longer have the article. This is the car, though: http://www.autosportengineering.com/9ff/jet_blue.htm I would bet that you could do better than that; one of the spec 996 guys is at 2550, but that's race car with almost no interior - not so fun on the road. Thanks in advance for any inspiration! Andy

this will give you some idea of weight loss in a 996.... http://www.6speedonline.com/forums/9...urbo-list.html

My SP996 weighs ~2600 lbs with no ballast in it and an empty tank. That includes a full cage. You can save a fair amount of weight by going to GT3 Euro seats. Somewhere around 45 lbs I think. A lightweight battery can also save a fair amount. The stock battery was IIRC 45lbs. My Odyssey weighs 13lbs, though I'm not sure I would want to rely on it for much street driving. Speakers, stereo head unit & amp will save a bit. Remove the rear seats. Muffler bypass if you can stand the sound. LWFW. Wheels Once you get done with this, rip the rest of the crap out and build an SP996. You know you want to...

My C4S is 3110 with a full tank of fuel & a 4 point roll bar. Without the bar, It'd be around 3060. I know this isn't exactly the lightest 911 out there, but I think it's pretty good for an awd car. Weight loss mods include: Recaro Profi seats Muffler Bypass Interior strip/spare tire removal OZ Alleggerita wheels I'm planning on a lightweight flywheel, cf roof for further weight reduction.

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Is that the whole list of what you've done? That's over 100 lbs lighter than my GT3 - which is almost 3250 lbs with fuel. (I just had it corner balanced about 3 weeks ago). And I have no sunroof, GT3 seats, limited sound deadening from the factory, and relatively lightweight wheels. I do have a bar and carpet, but not much else. Your car also has an entire forward transmission that I don't, so 100 lbs lighter than a GT3 in a C4S is pretty impressive. -td

Ahh mine's about 2425 without driver but not very streetable.....

That's an interesting thought ....... a CS Club Sport 996 , the car they never built. Throw in a 3.8X51 motor and it could get real interesting. Maybe I should do this for a street car for me. As the prices keep dropping on the 996's I think I will consider this more.

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I know you know all this Viking, but for others interested in a motor swap just remember to use a 02' or later donor car with the 7.8 DME. It can be programmed to run the X51 motor where the earlier 5.2 DME's can't activate the variocam plus. Yes I know you can use rev activated switches, but even so the 5.2 brain is limited in it's ability to tune the more powerful motor. You can also switch our the harness and brain, but by then you should just buy a GT3.... PS: Someone I know just built a 3.8 out of a 3.4 motor setup to run in a 99' car with cable TB . Heads are decked but with OEM vaiocams. All the right stuff, should be a very torquey motor and perfect for a GTS4 car ....

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Your GT3 is 3250 with fuel?? That seems really heavy for a gt3 doesn't it? I deleted my rear windshield wiper as well, forgot to mention that. Naturally the subwoofer & all rear speakers went out with the strip. I've had the car weighed at a few different places, so I'm pretty certain of the 3110 weight. The Recaro profi seats are lighter than the gt3 seats by a little bit, but my car does have the sunroof. Alleggerita wheels save about 36 pounds over the stockers & I get about 55 from the muffler delete. Edit: Breakdown: Muffler bypass: -55 Interior strip/spare tire removal: ~ -90 Alleggerita wheels: -36 Seats: - 75 Roll bar: +45 Total: ~ 210 pounds of savings, so my starting curb weight was around 3320.

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Nope. They are about 3100 dry. Add in 100 lbs of fuel and a roll bar, and poof, close to 3250. Also, I had no speakers, woofers, no back seats, no spare tire, etc. Maybe one day I'll put it on a diet... -td

Good thread. My plan all along was to lighten my 996 but so far I only got as far as deleting the centre console and one of the rear seat backs. I had both seats out but my wife made me put one back in for my little girl who sits in the back with a booster seat. My car is basically a no option car. It weighed 3050 pounds when I weighed it witha half tank of gas. That was before the console and seat delete.

So it seems like options make a big difference in weight. Your 996 is about 3100 with a full tank let's say, while TD's gt3, with some weight reduction, is 3250 with a full tank. This comes as a pretty big surprise to me.

Thanks for all the feedback guys! I forgot to subscribe to the thread so I got a bit behind... Replies ================ redridge, thanks for that - it's a great resource. I had seen it before but forgotten about it. mglobe, Thanks for those details as well. "You know you want to..." Totally right, and the full race cars give me a good idea of the limits, but this concept is to build something more streetable Varun, interesting. that seems quite light for a C4S. JR, dang. That's light. Interesting tip on the DME revisions. Jasper, could you give any more details on your options (or lack thereof)? Does the car have a sunroof? ================ More thoughts The concept I have in mind here is an early 996 interpreted as a 73 RS Lightweight type car. Not much in the way of creature comforts or sound deadening but still with carpet. Shell seats, probably replace roof skin if it has a sunroof, that kind of thing. No A/C, stereo, etc. Airbags and ABS not needed, though removing them may be more trouble than it's worth. Like the 73 RS, remove the glovebox door (just kidding!) The 9ff car is the closest example I've seen of this, does anyone have the Feb 06 Excellence that this is in? Seems like there would be other examples of lightweight street or street/track 996s out there, there are lots of different lightweight early 911 builds. A 1999 is supposed to start around 2950 or so but I'm sure that's with no sunroof or other options. Any other weights on early C2s? So take a cheap 1999 or 2000 996 C2, leave the motor as is, do some suspension upgrades, tear out most of what you can find. put a lightweight carpet kit and shell seats back in, try to make it a hard-edged but streetable car. I wonder what this would weigh. For example, what weight you'd have to add back to JR's car to make it a streetable hot rod. I know, it's a race car, you wouldn't do that, but you get the idea. 200lb? 300lb? carpet passenger seat maybe a little sound deadening steel doors if his aren't since you wouldn't have door bars what else?

I really enjoyed the article on the 996 Club Sport in the Feb. 2005 issue of Excellence (Issue #135) http://www.excellence-mag.com/back-issues?year=2005 It inspired me when I was rebuilding my current 996. The stock seats, cats, and wheels weigh a ton. My car weighed 3103 with a full tank of gas, spare, stock cats, and solid spoke wheels.

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This exercise has a lot to do with the accuracy of the scale used to weigh the car. The scale I used is a truck scale at the front gate of our industrial plant. It's use for trade and is checked periodically for accuracy. As a test I stood on it and it correctly weighed me at 100 kg (220 lbs). My car does have a sunroof, but no rear wiper, a plastic dash, standard leather seats (power rake but manual fore-aft) no BOse, yes litronics, it has the 18" Carrera III wheels (the liteweights, not the sport classic II wheels in my sig photo - those are my track wheels. It has air con like all of the US cars. That's about it. I'm totally with you on this. I'm planning a liteweight "light"...if that makes sense. Using the turbo weight loss thread for guidance.. I simply don't need AC in my neck of the woods - it's nice once in a while, but i prefer the windows and roof open. It can go. That's 25 lbs for everything including the pipework. I like my heated seats, but they don't offer much support and I'm probably going to get a winter beater anyway. That's 30 lbs if I swith to GT3 seats (or equivalent) Both rear seats - that's 22 lbs . The sunroof - I really like it so it stays. The spare tire and tools... 40 lbs I'd like to lose the rear lid and tail and replace it with a fibreglass ducktail type of lid. I haven't seen many of these, but they do exist. Not sure if there's much weight to be saved...lets say 10 lbs. . I could go in and dig out some sound deadeneing...it's pretty light nowadays though. Another 10 lbs ? When the clutch goes I will be doing a LWFW and clutch - that's 30 lbs That should get me down to 2880 or so. After that and it starts getting to be a lot of work for small gains or just plain expensive.

Thanks, Mark. I guess it was Feb 05, not Feb 06. Anybody have a scan of this they could email me? If so please PM. Otherwise I may have to buy the back issue, though I have purchased the magazine and read the article before, but got rid of it while I was moving! Jasper, thanks for the extra details. That is pretty light for a 2002 - I understand they are a bit heavier than a 1999, Frere said they were stiffer. Half tank should be about 50 lb of fuel, so that's 3000. That turbo weight thread says the factory roof with sunroof and interior is 47lb, so a non-sunroof car might save as much as 40? If a non-sunroof base 2002 could be under 3000, the quoted 1999 weight of 2920 or so seems plausible. Does anyone know the factory curb weight for a 2002-2003 or so? Probably in the owner's manual? Also, as I mentioned above Frere's Porsche 911 Story says briefly that the 2002 is stiffer. Has anyone been able to notice this or have any further information on why? When you remove the bumper supports, what do you replace them with? Or do you use aftermarket bumpers that don't use them? I'm really wondering how much weight could be lost from interior. Are there any lightweight door panels available like with the early cars? from the turbo thread complete interior carpet is 52lb, what about sound deadening? Here's a bunch of stuff that's claimed to weigh at least 38lb from the turbo thread: Andy

I'll weigh my 99 shortly on our corner balance scales, it will have no carpet or interior trim except dash, one light weight seat in it at the time....

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Hey Jeff! That should be interesting. Have you ever calibrated your scales against a known reference?

Jeff, I would really appreciate you reporting that weight. Looking forward to it!

Jasper, We set the cup car up on them to make weight so I think they are accurate..... But I could weigh myself! EDIT: it does have RUF 19's on it right now (for sale!) but will have my CCW 18's on it when I weigh it. Then we will add the cage...... Cheers

Not any real new "data points" but my car ('99 C2, sunroof, lsd) just weighed-in at 3,000 lbs with a 3/4 tank of fuel and OEM 18" turbo twists with Bridgestone Potenza RE-11s. I've done the following: All original seats (F&R) out; replaced by a Kirkey race seat with , a GT3 knockoff passenger and harnesses. Safety Devices bolt-in cage with "hard" padding. Orignal steering wheel and hub replaced with a detachable hub and MOMO wheel. Itty, bitty (umm, useless) 2.5 lb fire extinguisher. After Hours mufflers-AWESOME SOUND!; stock cats. The cats will go eventually as I figure out a plumbing job for pipes out through the center of the bumper--love that look. Radio and CD changer in the boot removed - after market amp and wiring removed after weighing-corner balancing. That removed about another 25-30 pounds not reflected in the 3,000. Seriously. That amp is heavy! Rear deck pad over suspension mounting points removed . . . weight savings 10 lbs??? Local wrench suggested leaving the trunk carpet in to save questions and and confusion with the less experienced DE tech inspectors who might look at all the wires and not know what to do. Whatever. Otherwise the car is stock: brakes, a/c, etc. I do use OZ Allegeritas with R1s on the track, and those are much lighter than the OEM/Bridgestone wheels/tires. I'll be conservative and say that the track wheel/tire setup shaves another 40 lbs total (probably more) off of the 3,000 lb figure. So with the amp now out and track wheels, I'll peg the car at 2,930. Stock carpet will come out eventually, but all the speakers will come out real soon. All together (6+) the speakers probably weigh 35-45 lbs? I'll leave the stock window controls and glass alone for now, and will not be worrying about a sunroof delete, new roof, hood, doors, etc. Until I've earned my spurs with consistent, competent driving, the money and time are far better spent with track time, instruction, tires, pads, fuel and lodging. I really don't know if there is any weight savings or weight gains with suspension upgrades, but I've installed PSS10s, adjustable mounting plates, GT3 control arms, tarret sways, toe links, various bits and pieces, etc. The car is street legal, but not really street-able with the Kirkey in. I can always take that out if "necessary." One guy's process . . .

Maybe I'm doing something wrong, but this is like the 5th C2 that is coming in over 350 lbs lighter than my GT3. Most of the things folks are taking out aren't even in a GT3 to begin with [sunroof, rear seats, spare tire, etc] - and everyone is running lighter seats. I can see 100lbs for wheels and mufflers, but where is the other 200+ lbs coming from? My car was just corner balanced and with driver ballast was right at 3400 lbs full of gas. Taking out the driver and gas (and including roll bar) puts my at around 3100 or so. Is there something simple I'm missing? Corner balance scales reading differently across the country? Gravity well? -td

60HP & high revs

^ Maybe as much as 100 at the wheels - my car showed 373 at the wheels on a Mustang Dyno, my old car [2000 C2] was more like 250.

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Porsche lists the curb weight of the GT3 at 3043 lbs. They list the curb weight of a 99' C2 at 2910 only a 133 lb difference. I don't understand either....

The Metzger motor is heavier than the M96...my understanding is that the GT3 was never lighter than the 996, but better in every other way.

Jasper, when are you actually going to strip that thing and have some fun with it?? Bite the bullet, the wife has a car, no?

Slow and steady wins the race Jeff. I'm doing what needs to be done on the car. At the moment that's a power steering rack and a new oil sump plate. In fact it's been so much work and kids over the last few years that I've been lucky to squeeze in a handfull of autocrosses. This years project is to build a shop in my backyard. It will be 18.6 ft wide and 42 ft long. I break ground this Wednesday in fact. Once the shop is in place I theoretically have no excuses left...except a lack of funds. It will be good to have your car as inspiration.

The C4 tub is heavier than the C2 tub, not to mention the extra reinforcements in the rear of the GT3. Of course the entire running gear is heavier, not just the engine (transaxle, axles, hubs/upgrights, brakes/suspension, etc). I thoroughly enjoyed tracking my 99 C2s, but they didn't drive much like a GT3 even w/similar suspension set ups. I think the GT3 is even more rear heavy than the C2 btw.

Ahmet, do you think that is because of chassis rigidity? Porsche did choose the C4 chassis for the GT3 for a reason...

Porsche has said that this was the reason. If I remember correctly, the 2004-5 GT3 has a modified C4S chassis which was mated to the C2's rear (narrow) section. Further modifications were made to the rear for mounting that engine as well as additional stiffening. Hard to say how much weight that all adds up to, but appears to be substantially more than a C2.

The GT3 vs C2 hp/weight ratio should be a hefty consolation for the 100+ lbs difference. On the other hand, I'm certainly not ready for a more tail happy car in the real tight twisties. Someday . . .

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It's all about setup. It doesn't have to be tail happy if someone who knows their stuff sets it up....

The trick for me has been to know that I found "someone who knows their stuff." I'm working hard to be an educated consumer so that I really understand what is going on with the chassis and suspension, how all the pieces work and need to come together, what elements I need or don't, etc. It's also been tough to understand what "results" I want to achieve and why. And, its been tough to understand whether I received good value and advice for the money. As an example, when I picked up the C2--moving from an '88 Carrera with some "work"--I immediately went to adjustable coilovers, adjustable sways, adjustable camber plates, drop links, etc. Leaving aside whether that was too much, too quickly, I had great difficulty with controlling the rear-end. Well, everything was set-up pretty darn stiff. But I did not really know or understand what that meant or what results would be likely at my skill level. Add poor throttle control--lifting--and I quickly became the spin doctor. I've since loosened up the suspension a bit, which helps as I develop better throttle control and feel. So, I'm learning what to look for and why. I'm also learning to understand how to difficult it is to find good value and advice for those hard earned dollars. The process continues . . .

Ahmet, I have also read that is the reason they used the C4 chassis, but when you say "I thoroughly enjoyed tracking my 99 C2s, but they didn't drive much like a GT3 even w/similar suspension set ups" what differences did you notice? Aaron, I do think too many variables were changed at once on your car and you need a good chassis guy to sort your car out. This will not be cheap but it will be worth it. I think this forum should be able to give you good recommendations for a chassis guy in your area, but that's probably another thread...

The GT3 has crisper turn-in and is a bit trickier to drive in part because it's throttle response is a lot more touchy, the rear end moves around a little bit more under load and breaks away more suddenly. The C2 feels more stable, and doesn't require as much minute input near the limit. For example I had to open the wheel in the GT3 at the uphill S' (@the middle bump) at VIR at 115mph indicated on street tires. At 110mph the GT3 feels a lot bouncier and more abrupt than at 115-117mph. Same thing at the kink at CMP, near the exit a GT3 is a bit more tail-happy. At these spots the C2 doesn't seem to be as lively, even on the same coil overs. All in all I'd say the GT3 takes more precision to rotate under trail braking at lower speeds, that's probably the biggest difference to me. Also as I alluded to above, the GT3 likes to be loaded and behaves very differently at 85-90% than it does at 95%. The C2 is progressive in comparison.

I've got a low-optioned 2003 C2 aero. It's got factory PSE exhaust, but no PSM. With no driver, no gas, no spare, no toolkit, no wiper fluid, no floormats, no stereo at all, empty trunk & glovebox, CCW wheels, 2 gt3 seats, odyssey 925 battery, and all else stock: it's dead-on 3,000lbs. If money/smog were no object, delete the mufflers, cats, sunroof, soundproofing, install LWFW and TRG carbon hood...you'd be at <2900 easy-peasy with no gas. And this is for a streetable mk2 with full A/C.

Definitely don't want to hi-jack the thread away from the topic of car & weight comparison. If anyone wants to PM me with their thoughts/recommendations for a good chassis/suspension outfit in the Philly area, please do.

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IMHO it's all about the LSD that the car does or doesn't have. Some C2's came with a 2 plate diff that was a very good LSD, but most are open diffs. And we all know by now that the GT3 diff is usually toast by 15k mile or less. I can't stress enough how important a good/functioning LSD is to a performance orientated Porsche. It's more relevant than shocks, springs, or even a mildy crappy setup.....

Thanks Ahmet, that's very helpful. One further question: in the C2s were you running rubber stock suspension arms and strut tops or monoball stuff? John, thanks. That's a very useful data point. Aaron, no worries - I didn't feel like the thread was hi-jacked, but I do think you would get some value in posting a thread looking for a suspension specialist, perhaps in the East US forum? Interesting feedback on the LSD, JR. Makes sense, a functioning LSD is a beautiful thing on the track.

FWIW, I haven't found that a limited-slip diff makes much of a difference in a C2. There's quite a bit of weight over the rear tires and the car doesn't really make enough power to spin the inside wheel. The GT3 would likely be a different story. I think it probably does make enough power to overwhelm an open diff in tight corners. Actually, I have witnessed multiple people carry on about how much they like the limited-slip differential in their C2 / Turbo when, in fact, those particular cars had open diffs. Also, at 46k miles the diff in my GT3 is still just fine. For that matter, my partner's '99, 114k mile C2's intermediate shaft hasn't exploded either, so go figure.

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I've actually driven a large number of C2s, including several of my own at different states of modification including rubber suspension mounts as well as monoball/spherical rod ends/solid metal "bushings". I've also instructed/ridden in quite a few different examples, same goes for the GT3s at many tracks. In my feedback I tried to concentrate on the things that I feel carried across all C2s vs. GT3s. Of course as the LSD debate shows, many people disagree on car set up. Another example is suspension stiffness, I think the GT3's factory set up is bordering on too stiff (for street tires or a lower grip R-comp) at CMP whereas at VIR a stiffer suspension seems a bit more beneficial. -Though without enough tire wouldn't suit certain sections well such as the upper S'. Speaking of LSDs; I've driven a "higher" mile GT3 that sees the track several times a year which doesn't have any symptoms of a bad diff. LSD makes the car a bit more easy to control during oversteer and causes a small amount of understeer on power during lower speed turns, but that's about it. The Caymans and turbos (and 944 turbos and such) will spin an inside wheel on power but for a C2 I don't think it's really necessary. I suppose with a stiff enough set up it could be more of an issue.

Nice sized shop Jasper! You know me, I will likely sell car once we have it fully sorted... Lost of interseting insights into the LSD.... I like them for what they do under braking but YMMV.... Cheers

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Exactly. Carrying a 450 lb. weight behind the rear wheels while breaking into a turn at speed can be a touch tricky. For me, the benefit of a good diff isn't just controlling wheel spin under accelleration, it's the ability to go faster and deeper into a corner without the car trying to swap ends or jump into the stands. Once you've learned how to take advantage of a diff with a high decel lockup ratio like Guards 50/80 you'll wonder how you lived without one....

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+1000 I was not a believer in the need for an LSD until I put one in my race car. It's much more stable under braking, and the back end is a lot more planted on exit... provided you keep your foot in it.

Since there are no stupid questions . . . How do you tell if a lsd is still properly/optimally functioning?

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Do you hsve one in your 99'? They're quite rare and a good LSD to begin with, much better with Guard's replacement clutches which aren't very expensive. The easiest test is to simply jack up one side of the car leaving the other rear wheel firmly planted on the ground. With the trans in neutral and the parking brake off try to rotate the lifted rear wheel by hand at first. If it rotates you either don't have a LSD or it's clutches are worn out. If it doesn't rotate then remove the wheel and put a torque wrench on the axel nut and try to rotate the lifted wheel. Start at 20lbs, 30lbs, then 40 lbs, etc. until it breaks free. That breaking point will tell you the condition and ramping preload of the LSD. Please report back with your findings....

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Engine weight as per DIN 70020 A in kg (lbs), Manual transmission ( According to the WSM ) 190* (418.86*) -- 3.4l 274.0* (595.2*) -- GT3 mkI 260* (572.7*) -- turbo * including double-mass flywheel

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Thanks JR. A VIN check confirmed a factory lsd. But, at 118,000+ miles, and who knows how many track days other than mine, I do begin to wonder. Since I need to do a brake bleed between sessions, I'll do the check within the next few days and report back.

sprintmax, Not to take this thing too far off the original track, but you might consider heading over to Maryland instead of Philly for your set up needs. What I mean is schedule an appointment with Mike at TPC in Jessup. I'll give you an example. Last fall he spent a day at VIR with a car (a Cayman but it doesn't matter) that was what we in the business call an "internet" car. It was loaded with all the usual coilover and sway bars and end links and strut bars, etc. etc that are very popular on these forums. On paper the car should have been fast. In one half day at the track, with corner weighting and lapping, Mike found something like 10 seconds a lap on retuning the guy's setup. I cannot emphasize strongly enough how important it is to have a professional who knows these chassis doing the suspension set up for you. As for the whole LSD conversation? Results don't lie. People can say that their factory LSD isn't worn out or that an LSD won't make much difference. All I know is I have rebuilt BRAND NEW 2010 GT3 RS LSDs and the customers found 2 seconds or more a lap before and after. Maybe the LSD did work the way Porsche intended it to, but if it did, they didn't intend it to be much of an LSD at all...

I'll look into TPC. Thanks for the info.

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Not hard to believe at all, lots of goodies don't necessarily make a car fast or fast-er, particularly w/out proper set up, which is not easy to come by. Porsche's LSD is intended to be very weak in order to allow the electronics to brake (or accelerate as the case may be) an individual wheel independently of others. For a track application, perhaps a good LSD would make a big difference on a C2, I've just yet to witness that. Remember that more track oriented/advanced ABS systems (BOSCH 5.7?) can help keep the rear wheel rotation speeds close under deceleration as well. Aaron, I only put that car on track a handful of times on street rubber before selling it to you, I doubt it's seen any other track use before that. I'd be interested in hearing about the breakaway torque none the less.

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The Bosch ABS unit will definitely let you brake harder without going into the ABS mode, but I've never heard that it balances wheel rotation speeds. I'll ask a GA 997 racer/friend. Also, that unit costs $10k for the part compared to Guard's LSD at roughly 25% of that cost. His disc replacements for the factory LSD are even less at about $750. Here's video of my car at Cal Speedway a few weeks back at a NASA race. The camera car is actually a pro-truck and although I out-qualiified him, he along with half the field, pass me on the start in my low HP 996. After the start fast forward to the 4:40 mark and I come back into the pic. If you follow us around you can see my car breaking at 155mph off the banking lap after lap. We go around like this for 5 or 6 laps until he spins but it gives a good view of the stability of my rear end under hard braking. It hardly moves especially when I trail break into a corner.... FWIW, the white #23 993 RSR is Chris Cervelli's old car.... http://www.youtube.com/user/american.../3/q-HXJi1JasM

JR is right. If you are DEing the car, I wouldn't term an LSD essential. But if you want to win the kinds of titles that JR and Jay Matus are winning with their 996's then it's a required piece of equipment.

How much of a difference do you guys with street cars notice from taking out 200lbs or so? I find my 996 a little to docile for my taste and was thinking about changing it up a little bit.

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200lbs is huge. How do plan on removing that much weight from a street car?

Spare tire & tools, lightweight front seats, delete backs, muffler bypass, lightweight flywheel, lightweight wheels & Tires, and whatever Else I could take out that is bearable. Shouldnt the bypass, rear seats, and spare tire & tools take off ~100lbs alone?

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Maybe since the mufflers are really heavy pigs. Even so, where's the other 100 coming from? I'm not trying to persuade you from trying, but I think you're optimistic unless you go to lighter body panels or strip the interior.....

I know changing the wheels can save some substantial weight. In that process, how many of you guys went an inch smaller at the same time? Not only would that be a drop in weight, specifically rotational weight, but the smaller rolling diameter also makes for a shorter effective final drive, which would help acceleration even more.

Don't forget to syphon out the washer fluid. If your car has xenons, it's 1.5 gals... that's about 12 lbs right there. Four floor mats = 5 lbs. Bose or aftermarket stereos are notoriously heavy (mine was 73lbs total). Removed! Rear seatbacks, belts & pads = another 22lbs. Of course, if you fill up the gas tank you negate all that. Drive around with a near-empty tank and all the above removed... see if you can appreciate the difference. If this is just a street car, and you can't appreciate the difference behind the wheel, then don't worry about it anymore.

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.

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?

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.

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.

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

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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.

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?

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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.

bump for another lightweight 996 thread

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

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.

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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.

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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.

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).

It's beautiful! That weight is insanely light.

Dang that's awesome.

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I forgot to mention that the motors in these cars have been put on a serious diet by Porsche. The gear box is heavier than a street non-GT3 996 and the engine may also be heavier than a non-GT3 motor. However, Porsche went with very thin castings for the water management on the RSR (much lighter than the previous GT3 race cars such as the R and RS). These also have 5lb Inconel headers and a $5K McLaren built 200A alternator that looks like a 40A toy alternator that comes on a civic. Unrestricted, the car puts out 540hp so the drive line has to be kind of heavy to be tough enough to handle that in endurance racing. In all, I think you can get a street car down pretty light if you start removing things and throwing them in "to be used for the restoration later" storage shed.

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FWIW.... My latest 996 is a 03' X51 sunroof delete(steel skin) and weighs 2,500 empty, about 75lb. more than my 99' 996. Nothing much different between the 2 cars except the 03' has a chromoly cage vs. the DOM cage in the 99' car. The 99's were just lighter to begin with....

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It had to do with the tub or chassis itself, they used more steel reinforcements in the later years to increase torsional rigidity. The even used different types of steels in places to step up the rigidity. I have the documents that PORSCHE put out that goes over the improvements. It was a big help for the street cars to feel more solid, be quieter, and handle better. That extra rigid chassis came at the expense of a little more weight. In reality, if you did your cage correctly then that factory extra steel won't help the chassis any because the cage will be doing a much more serious job of adding rigidness. Let me know if you really want to know more JR., if so I will try to dig up the documents from PORSCHE that explain it in greater detail. Btw, as I remember it your 99 had a 1.5" and pretty bare bones cage, correct ? I'm guessing this 2003 car handles much differently than the 99, can you feel the difference ? I know there are numerous other changes as well so it might be hard to tell.

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I've always been under the impression that even with a full cage tied into the suspension pick ups, that the chassis inherent rigidity is still important. Basically even with a well built cage it's not good to shed weight at the expense of weakening the chassis.

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True, but a well built cage will do more than PORSCHE did with their additional metal.

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Absolutely agreed.

Interesting tips in this (old) thread! You might also want to be aware of this build thread as it contains some interesting bits including lots of details and pictures of a CF roof conversion, a custom built steering rack and much more: The 996 CLR (after his avatar CarreraLightweightRacing) Intro to the build: https://www.pistonheads.com/gassing/...f=48&t=1604071 Build Thread: http://911uk.com/viewtopic.php?t=106137

Threads like this just can never die! They shouldn't. New ones often end up quoting or linking to the old ones.