Does turning off PSM have an effect on this? I tried turning it off on one recent relatively hard launch, and it seemed to result in less hopping effect.

 

911 cars are known for wheel hop. From Car and Driver July 2009, p. 40 on Porsche GT3: "the biggest benefit will come during acceleration...and minimize the wheel hop that can sometimes mar hard launches in 911s." It's not your tires and it's not your driving causing it.

 

PDK will solve it

 

I can't even believe this question is being asked. The 911 was never designed for the abuse to which you're subjecting it to. This is not a characteristic of the 997. It's a characteristic of every 911 going back to about 1973. Before that they didn't have that much rubber in back to cause this. The issue is simply that you have weight over your drive wheels, and those tires are not going to slip. What has to give is your clutch, and your suspension as it fights to keep the tires on the pavement.

I would suggest that if you want to avoid your problem either put very narrow tires on your back end or learn to drive a 911.

The 911 should easily deliver over 100,000 miles on a clutch,--what's your track record there?

 

Edgy let's say I disagree with you and leave it at that. What I don't understand is what's with your attitude and better than thou mentality? I asked a simple question and I wanted to hear what people had to say. If you don't have anything constructive to say or add to this thread why did you even bother to post...

What there isn't hard launches in road racing? I never abuse my car, in fact I have over 14k miles on the original Pirelli PZero's. Its just that a few times that I launched the car hard near the end of the rear tires life the car would axle tramp viloently and I would have to back off.

I have been driving manual tranny cars since I was 12 and have had clutches last well beyond 100k miles on several cars. The issue is that if the rearend starts to slip in these cars there can be axle hop. According to Fabryce at GMG a LSD as well as some stiffer dog bones can go along way in curing this. It won't solve it, but it will make it less pronounced.

As you see the date I posted this thread (almost 6 mos. ago) I have learned this is a characteristic of this car and will have to learn to live with its one of its very limited short comings.

I have enjoyed and read your posts now for almost 2 years...don't know what I ever did to deserve this sarcasm and hostile post when all I did was ask a question.

Dave

 

I think the issue is that I'm surprise that there are 911 drivers out there today that are unaware of this characteristic. I suppose I should recognize that we gain new Porsche drivers to the crowd every day and leave it to that,--that they will learn in due time, that dropping the clutch only results in what you have been encountering. Have you adjusted your driving since then? That's the real lesson here,--learning to adjust accordingly.

I'm not aware of 'hard launches in road racing' to the degree that you seem to feel that it's routine out there. Are you focused primarily upon drag racing? (That's not road racing). Perhaps you have the wrong equipment for what you choose to be doing.

Dan

 

Dan you have to remember that in an actual road race in which 997's are participating in they have a LSD installed as well as different suspension setups that minimize this. Unfortunately US cars before the 997.2 weren't afforded the luxury of a LSD.

I have drag raced as well as road race and yes I was tryinig to cut a good 60 ft. time but found the beating the car took the few times I tried it conviced me not to do it again. Those really good acceleration times that Road and Track got all mention to get those times it required you to drive the car with the axle violently trampping all the way into 2nd gear. Ouch!


Dave

 

It's a great car but not truly suited to that sort of driving. Take that puppy to Buttonwillow or willow Springs and REALLY give it a workout!

I assure you that such violent action in the back end of these cars is not doing your wallet any good. Sometimes we forget that these cars have small displacement engines (a 3.8 litre is what, 230 cu inches??

dan

 

Is there any wheel hop for the 09 PDK with Launch?

 

Dan/Edgy01 is absolutely right and the OP is wrong. I suspect the OP is trying a burnout start typical of an American muscle car. These cars were never designed for that. They were designed for maximum traction, not slippage. Wheel hop happens when they are abused. They can be launched very fast but there are limits of traction and low-end torque. Not an issue, just bad application. Sorry!

 

No because the system adjusts clutch slippage/engine torque/traction optimally. It does not do a burnout.

 

Can't say that I agree entirely with this. If our cars were built for "maximum traction" then IMO they should have come with LSDs.

Even during an auto-x - a good launch saves tenths. For that matter my completely torqueless wonder (S2000) actually launches pretty well. It sounds harsh - but dumping the clutch @ 5,500 rpm gets the car going very nicely - and the tires break loose momentarily without the axle-hopping nastiness of my C2S.

 

An LSD can be mounted in a 911. PAG offers an LSD option on the 997.2. But even w/ LSD you can get wheel hop if you abuse the launch. The all-in-the rear design eliminates/prevents slippage and it can/should be used to advantage.

 

Absolutely wrong..I was just trying to launch hard. Never been into smokey burnouts. I have owned IRS equipped cars now for quite some time now and know very well what the limits of an IRS equipped car. Live rear axle is what you want if you want to do smokey burnouts.

I have to say your post comes across arrogant and as a know it all...

I was just wondering out loud is there anything in the aftermarket that could minimize this...jeez. Half way through 1st gear the car starts axle tramping, mainly since I am at the end or my Pirelli's life. Once again read my other posts..I have over 14.6k miles on my original rear Pzero's...got to be a darn near record on this site.

BTW, an LSD would help out greatly with axle hop...never will solve it but it will minimize it.

Dave

 

Exactly...half way through 1st gear the car will start to spin sometimes and it will hop like a mother. At launch I control the wheel spin, it's when it hits that vario cam power and tq. range it will axle hop sometimes.

Dave