Porsche911Carrera2

Last night I stepped on it in third gear and noticed that the car started to pull left. As soon as I lifted off the car went straight again. The road was 100% staraigh so I know it isn't from the road sloped to the left. It only happens under harder acceleration and now I notice it in every gear. I have a fantastic bumper to bumper warranty so I'm not scared of repair bills. I just want her to be healthy. Any ideas are VERY appreciated.

Bob Rouleau

One rear tire worn more than the other. Alignment knocked out?

Porsche911Carrera2

Brand new Michelins Pilot Sports 4K miles ago and in excellent condition, car normally drives perfectly straight, tire pressures fine, could it be something to do with driveshafts or the differential?

I remember back in 2002 I drove a brand new SL500 (new body) and it was doing the same thing under floored acceleration. It seemed weird but I guess maybe it's normal. My other car is an Audi A6 Quattro with zero torque steer so maybe I'm just too sensitive.

TamiyaGuy

Despite the fact that it's going straight normally, I'd have the alignment checked. All 4 wheels to ensure that everything is up to spec. Have you owned the car since new? Is there any accident history which required repair work on the back?

Jeff000

Roads are never perfectly flat, they are always sloped so water doesnt sit on them.
The reason it pulls is just from the torque of the rotating mass and the way the power meets the pavement.
Its easier to notice on older muscle cars, if you watch them launch or get on it hard the right side of the car will squat more then the left.
I cant remember exactly, but it has to do with the centripetal forces of all the rotating mass in the car and how the diff works. Been a few years since calc 302.

Porsche911Carrera2

That's exactly what was going through my head. You are right, those muscle cars do squat unevenly, more on the right then left when launched hard.

Porsche911Carrera2

Zero accidents/repair work. Not owned since new.

springgeyser

Doesn't happen with my 996 under WOT. Sounds more like a loose suspension component.

gregorycarl

+1 - if it is a severe pull.

My car will move a bit under hard acceleration. These cars come alive under throttle...isn't that why we own them. I hit my SUV hard, straight and unexciting.

waldrondigital

There's a post in here from last week when I complained of the exact same issue. When I accelerate (the higher the torque the more pronounced the kick) the car wants to push left, when I ease up it goes to center. Very strange and super annoying. A helpful poster also mentioned that this problem could be a worn suspension component. I just had the car aligned last week and it drives perfectly straight.

Please let me know what you find, I'd like to fix my issue as well.

waldrondigital

Here's my thread talking about the same problem:

https://rennlist.com/forums/showthre...=1#post4797121

Jeff000

You will never find the "loose nut" except behind the wheel. :P

Worn components and loose parts make noise, and a lot of it.
I used to be into F-bodies and Vettes a lot, and they ALL "pull to the left" under hard acceleration, untill a certain point and then the tires just break loose. Its pretty easy to tell the "pull" is from the power in the modified F-bodies and even the vettes, although the suspension in the vettes are a bit tighter and better designed so it sometimes feels like something is loose or miss-aligned.

Go about 15mph in 1st gear and hammer it hard, see if you can feel the pull left just before the tires break loose, I assure you that is not from a loose nut or worn anything.
I had a worn LCA bushing once, and it made a huge racket every time I slowed or accelerated, or turned, or hit a bump. But didn't cause the car to pull. When I put the new bushing in I broke my wrench and it wasn't even tight enough to close the gap, and the drive to have the wrench replaced was quiet and smooth, despite the fact that the bolt could move ~1/8".

If something was loose it would probably pull more under braking then acceleration.


But for safety reasons I think both of you should just sign your car over to me so I can properly "dispose" of them. :P

Porsche911Carrera2

I was told today by a Porsche service advisor that it's just torque steer and that I shouldn't worry. He mentioned un-equal length drive axles and it all makes sense. I just buggs the crap out of me

waldrondigital

I don't remember this happening until fairly recently. I think I would have noticed it prior, but who knows. It IS annoying.

waldrondigital

An update. Today I traded from 20x11s to 20x10s wheels in the rear, but kept the same tires. Unfortunately I didn't see which tires went on what wheel (should have looked - doh!) .. read on.

The weird part:
Now my car pulls right upon acceleration and goes left/center when I let off (opposite of what was happening before where I would accelerate and the car would push left and go back to the right/center when I let off).

Can I conclude that one of the tires in the rear is screwy?

Hey Porsche911Carrera2 - have you tried swapping your rears to see if you get the "opposite" effect like me?

Something's definitely rotten in Denmark.