intouch1

tried some acceleration runs today. timed them manually on the sports chrono.

best 0-100 with power-braking: 4,24 sec
best 0-100 without power-braking: 4,9 sec

with power-braking 0-200: 12,9

would also like to know if powerbraking has negative effects and could harm the driveline.....
was holding the brakes up to about 4,500 rpm.....

atomic80

It's BAD, really really bad for your powertrain. I wouldn't recommend doing it unless you absolutely had to. I did it once to a friend's tip and IMHO, it's not worth it.

Edgy01

Of course it will. I guess I don't understand people who buy these to do this sort of thing. What I do know is that you will turn the car in within 18 months to get something else to abuse, and whoever the poor sucker is to get your car will wonder why it's not working correctly in 6 months.

Go buy a sprint car.

hatchback

Easy guys... I think intouch1 is asking an entirely reasonable question. Porsche publishes some amazing acceleration numbers for the turbo tip, and they shouted out to the world that the turbo tip is faster than the turbo manual. The only way for the tip to be faster than the manual is with the agressive "power braking" launch that intouch1 used. So I think he is asking a very reasonable question. Also I believe that Porsche should cover any damage caused by an agressive launch since they are telling everyone that such a launch is required to achieve the advertised acceleration numbers.

intouch1

thank you hatchback. finally someone understands what the intention of my post was.

do you have any more info for me concerning applying this launching method and if it is bad for the driveline ?

when accelerating in gear from lets say 30 km/h and applying full torque, its loading quite a bit of force on the driveline as well.

i just dont want to abuse the car or damage anything.

kudos......

Nick_Athens

Maybe we have to contact Porsche PR department and ask them how they achieved the 0-100 in 3.7 cause I own a Tip as well and I find my car slow in start..

hatchback

Torque braking puts huge stress on the torque converter because most torque converters are designed to engage/lock by 2k rpm. It cannot be good for the drivetrain to have one end turning at 4k+ rpm with 500 ftlb of torque and the other end stationary. How bad, I don't know, but bad. A full throttle acceleration from 30kmh will put some stress on the drivetrain but the torque converter will be locked and the drivetrain is surely engineered to handle that stress. In the worst case the wheels will slip/spin which will limits the amount of force that is applied to the drivetrain itself.

Some things to check... (1) Many automatic transmissions start in 2nd gear rather than 1st which will kill your launch. So use manual mode to put your tip in first gear for the launch and then quickly switch the transmission to automatic mode as soon as you release the brake. (2) Make sure you're in sport mode for the launch. (3) try the launch both with and without traction control. For some cars, traction control makes for faster launches and for other cars it slows down the launch. You can test this by timing a normal full throttle launch (ie., without torque braking). (4) in the edmund's article they say to wait for overboost to activate before releasing the brake pedal.

I've never driving a turbo tip so I'm just guessing based on my experience with other automatic transmissions and my limited understanding of transmission design.

hatchback

Also per this post don't press the accelerator pedal down all the way.
http://www.6speedonline.com/forums/s...ad.php?t=75675

ldye

Service tech where I purchased my Turbo told the wife to power brake the car up to full boost and hold on. He said it wouldn't hurt the car. Now I'm sure it can't be good for it but you can bet I'm going to try it a few times after break in.

AndrewP

I am considering the 997TT with Tip largely because Porsche says that it is faster than the manual. Driving with a manual is much more engaging than with the Tip, as I have found in our 997 C4S, however so the trade-off seemed clear with the TT. I am now concerned that to get full potential from the car may involve drive line damage. The sales mgr at my dealership claimed on Saturday that with sport on and power braking and starting in first due to the Tip's second gear start mode, the car turns 3.2 second 0-60 times. I do not want a drag racer, but must say that if one can only squeeze low 4 second or for that matter high 3 second 0-60 times out of the new TT, I am disappointed. I would have thought that this subject would have been discussed before.

AAHTT

It was discussed before and I will post my opinion again: if you are looking at a TIP because it is faster, you will definitely be disappointed sooner or later, because you can't keep power braking the car all the time.
If you can drive stick well, get one and you won't regret it, period.

dasams

It blows me away that someone would make the manual vs tip decision based on the stated 0-60 times. Sure, you can do a brake stand with the tip to pick up a fraction of a second but what about the other 99.9% of the time? And now we have news of the throttle step down switch.

Jeeze, buy the tip if you are constantly stuck in stop and go traffic and don't want to bother with a clutch. Or buy the manual if (fill in your favorite reason here). But don't base the decision on the brake stand 0-60 time. Flame away if you must.

AndrewP

Thank you for your post and invitation, but it is obviously unnecessary. I am sorry that I offended mvd with my questions and assumptions. I have not driven the 997TT and the only reason that I would get the Tip is if it were much more responsive than our 997 C4S with Tip. I have since read the post on the other forum on the subject, so received an instructive answer to my question. My winter ride is an 07 RS4, which I enjoy enormously (with its 6 speed manual), although I do not drag race it and would not likely drag race a 997TT either.

dasams

Andrew - Apologies for the tone of my note and it certainly wasn't directed at you although, unfortunately, it was a reply to your post. Since Porsche first announced the tip was quicker off the line, many people have stated this as a reason to go with the tip. And that's great if it's that important to a buyer. But there's so much more.

Congrats on the RS4. Now THAT must be a hoot!

ebaker

Power braking heats the trans fluid rapidly. As long as you don't power brake for too long it shouldn't hurt the trans.