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U Boat Commander said:
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londondude said:
I remember a post not long ago regarding hard launches. It was noted that they were very bad for the mechanics and shouldnt be done.
Well if I was feeling imature and I was for example at the lights and a hot hatch was wanting a race (the ones with more modifications than a dragracer) then can people here give advice on how is the best and safest way (for the car) to lunch?
being a sports car it should be up for this type of thing.
Let the clutch out quickly and floor it as hard as you want. Just don't fry your clutch. That is, don't floor it and let out the clutch at the exact same time and don't rev the engine before letting out your clutch. You could easily destroy your clutch in two seconds and that is NOT covered by your warranty. It's a delicate balance where a fraction of a second can make all the difference between blasting off perfectly and sitting at the light with a burnt out clutch. After a few practice runs you ought to get the hang of it. Remember that you don't even need to give the 997 (or the 996) any gas when letting out the clutch. The car will roll without any gas at all. So start off your practice runs by letting the clutch out and then hitting the gas. Each time you do it try to time the gas closer and closer to the clutch. Eventually you will get to the point where you feel the clutch engage and that's where you want to hit the gas. And you'll also know if you blow it because you'll smell your clutch for hours (maybe days) later.
Let the clutch out first, and THEN hit the gas?? LOL!!! U boat, have you ever drag raced competitively, at a track? You'd be getting schooled by Camaros my friend, leaping off the line so hard that you'd be 3 car lengths behind them before you clipped the 60-foot lights. If that's how you launch for a street race, I'll run you zero-60 in a Kia Rio towing a U-haul car dolly for pink slips, and I guarantee I'll own your P and be pulling it home on my dolly at the end of the race!!!
If everybody launches like that, it's no wonder I've never lost a standing-start street race in my life.
For the record, if you do an off-idle clutch-engage, and then floor it, you're so far down and out of the good torque band, that the race is lost before you get to 20 mph. There's night and day difference, when you put a clock to it, launching aggressively in the power band versus popping the clutch from idle and forcing the car to climb up to it's powerband. It's the reason that automatic trannied drag race cars run stall-speed converters that bring revs to a specified high rpm before converter engagement. It's the reason that you get quicker results in an auto trannied street car at the strip when you spin up against the converter with your foot on the brake to increase launch rpm.
You're DEAD when you're fully engaged, between 1,000 and 3,000 rpm, in a Porsche flat-6.
You shouldn't have a problem frying the clutch doing a 3,000 rpm drop, just make sure you DROP the clutch, don't slowly let it out, allowing the pressure plate to slip rather than clamp. If you're too conservative with the revs, then you don't get enough "leap" on clutch engagement to keep the revs up, and you bog, leaving you no better off than you would have been doing an idle-launch like U boat suggested.
I raced NHRA Sportsman regularly for 10 years between 1988 and 1998. My stock original clutch in my modded 5.0 Mustang finally gave up the goat at 70K (replaced with a Centerforce dual-friction that was an animal of a clutch
). I was young, and abused the daylights out of that car, and that clutch was enduring hard 2,400 rpm launches (more low-end grunt, not as many revs necessary) every weekend, with 80 more horsepower than stock to hold onto. After the Mustang, I bought a new 1993 Corvette LT1 with ZF 6-speed. A few mods later, it was running consistent 12.90's @ 107-108 mph. I launched that car at 2,800-3,000, depending on track conditions. It had 60,000 miles on it when I sold it, and the clutch was still operating great. Those are cars that won Sportsman trophies at divisional meets, ALOT of abuse.
Doing a properly executed hard launch, every now and then (I mean, honestly, how many times do you really have a "drag race" in your 911?
), isn't going to fry anything, unless you slip the clutch like a dummy, or go too high up the rev-band. The magazines have all been accomplishing their impressive 1/4 mile and 0-60 times with 4,000 grand drops, so I've read, and the clutches have been grabbing hard and not slipping. But even still, I'll reserve such a monumental effort for an icy cold evening when I go up to my old stomping-grounds, Gainesville Raceway, to get some accurate timed runs on my 997S this November (may as well wait for cold weather to get the best times). But a street race isn't worth going 100% out for, so that's why I recommend a more conservative 3,000 rpm.
Fact of the matter is, that poor technique in everyday normal driving is far more detrimental to a clutch's lifespan, than a rare heavy launch. One gorilla launch is nothing compared to thousands of days of bad throttle matching combined with ham-footed clutch engaging in daily commutes.
While I got 70K miles, drag racing every weekend, out of my stock Mustang clutch, my buddy's girlfriend had totally worn out her 5.0 Mustang's clutch in 25K miles, bone-stock engine, never raced, just lousy driving technique.
You can learn a lot about launching a car with a few weekends at the dragstrip. 
Most people are hesitant to treat their cars that way but I'm with you, I've launched using the same high rpm/sidestep the clutch technique many times in many different cars and I have never replaced a clutch before 70k miles.
