MMD

Hummmmm..., that's a good point. Our cars advertised as getting 4.7 secs (?) are probably warmed up and on hot sticky pavement. There's no standards for these 0-60 tests (are there?) so I betcha they can do it on a dragstrip with sticky additives that "just happen" to still be on the track and get away with it.

doc2s

that was road and track magazine

1AS

All rear/mid engined Porsches (possibly excluding CGT which I haven't driven) exhibit rear axle tramp instead of the more desirable screech of burning rubber. It is destructive to the driveline, and is the reason that only magazine writers driving cars they don't own can achieve advertised 0-whatever numbers. Our cars excel in most other areas, but not drag strip launches.
I believe the mechanism is due to spring wind-up. The rear weight bias which promotes getting the power to the ground is an exaccerbating factor.
We aren't alone in this, as my BMW 850CSI does the same thing, as did my 1969 Lola T163 Can Am car.AS

MMD

Here's an idea! On Porsche's website they should show their cars obtaining the sub 5 sec 0-60. They should show them on skid pad, spinning out w/all, w/some and w/o PSM etc. The braking, all should available to see. Would "prove" their numbers. My bet is if you saw what they did to get those numbers you'd never see your car the same way.

zumaron

Just Another Data Point (JADP) -- I've experienced this in vehicles of all shapes, sizes, and design. Except for cars that had very stiff suspension and high performance traction control.

As was pointed out earlier, this car is not a dragster. Rather, it's designed for handling and control at high speeds. Finesse is the key to achieving the type of launch you are describing. Rev'ing it up and dropping the hammer will not accomplish much except for maybe breaking something.

Basic description of how wheel hop occurs --> http://www.competitionengineering.co...s/chassis2.asp

BiggerTwin

Porsche's performance numbers are conservative compared to the magazines and I suspect they don't beat the cars as hard as motojournalists do. I think Car and Driver's 5-60 mph times are more indicative of what an owner who has to pay for repairs can expect from his or her car. It is interesting to see how the 0-60 and 5-60 times vary between cars. The Audi S4 and Cayman S had the same 0-60 times but the Cayman was faster 5-60. While axle hop is the most dramatic abuse, I am not happy about burning rubber or clutches just to beat some kid off the line in a WRX or Mustang. Each car is different and I try to figure out what is the best combination of gas and clutch to get the car in gear quickly and then let the engine do the work instead of putting unnecessary strain on the drive train. If you want mind-blowing acceleration, for less than $10,000 you can buy a Japanese sportbike and save your Carrera a lot of wear and tear.

Alan

ronmart

For those who seem perplexed as to why anyone would want a AWD 911 outside of the winter months (or in regions where it never snows), this is EXACTLY why. You get the fast launch without the loss of grip.

WCE

I agree completely with the above.
This may be the best benefit of all wheel drive in these cars! The all wheel drive gives you the fast launch with barely a chirp from the tires.
Even my turbo will start rear wheel hopping in certain situations if I manage to overpower the tires!

soltino

Then you can't get "Hopping" in a N/A 4WD but you can in a Turbo <?>

tino

jumper5836

Nah I get it, AWD but really its only 5% power going to the front

cgng30

I noticed the same thing, I tried to do a quick launch when i reached close to 2000 miles, just to see how the car handeled. I got wheel hopping twice, I thaught I was doing some thing wrong. i wonder if i damaged the defrential or the suspension. This is my first porsche

icon

porsche shows one tenth of a second difference in 0-60 times between the 2s and 4s with the 4s ahead.
in 0-99 times though the 2s beats the 4s by one tenth of a second.
the 2s also has a 3 mph higher top speed than the 4s.
i don't think launch is a valid reason to buy a 4s.
you just like the wider rear end!!!

icon

i don't have any problem with hopping on launch.
but i have been driving porsches for years.
i think a lot of these hop problems are coming from people used to heavier vehicles that could be launched in the manner they were used to without hopping.
it's all relative!
a friend of mine had a mclaren f1 for 3 days to consider purchasing.
he was used to high performance cars but when it came to launching the 2500 pound mclaren f1 he had problems with hopping.
once you get used to the car, hopping on launch shouldnt be a problem.
porsches are lighter than most of the competition. the competition gets power to weight from horsepower.
heavier car equals less hop

1AS

Jeff,
I think there is more to it, but essentially it's a matter of design and grip. The twisting forces due to power applied to the rear axles will either cause the tire to spin or the spring to wind up. When the traction is enough to make the spring wind, it compresses until it's force exceeds that applied, then it expands, causing that wheel to hop. Solid axle cars can do this too, but are more resistant.

My old Olds 442 just burned rubber until I put on race tires for gymkhana's (now called autocross), then it had hop.
My Lola would do it (mildly)on cold rain tires, but cold slicks just spun.
My 1990 C4 did it in dry conditions but not snow and ice. I won't even try it in my tt.
I think you can avoid it by clutch slipping, but then you are brutalizing the clutch. Fastest standing starts typically require some wheelspin to keep the engine in the power band.
The factory testers were quoted on the 993 tt as saying the ideal launch involved the right number of revs(about 4000 by recollection), and sidestepping the clutch. Then, if you do it right, the whole car shudders for a moment, then takes off. But even they admit they don't get it right each time. There are only a limited number of such launches the driveline will tolerate. Do it enough, and you will be able to inspect your differential by examining the pieces you pick off the asphalt.
BTW, my 1991 C2 cab tip did not do this, nor will a Boxster tip, since the torque converter absorbs the shock, and neither can spin the tires from a standing start.
I'm not an engineer, but I think I got the basics right. AS

SrfCity

Yea, if you read the latest Motor Trend, "Dial 911" they talk about the hop off the line. It's caused by the fact that there is so much weight on the rear wheels compared to say the Z06.