... runs straight without throttle input.

Car moves three lanes over if not counter steered with 25% throttle accelerating from 40 to 65. It does this in Normal, Sport, Sport Plus modes.

And here is the best part:

Dealer had Porsche Factory Rep look at my car. He says it is "normal" and will NOT even attempt to fix it. He wants me to just live with it.

The car has 20k miles, no accidents. So he claims the 20" wheels are causing it.

Before I brought the car in it handled perfectly. Porsche took the motor out to fix some minor oil leak and replaced the rear right shock. They claimed they did not need to do an alignment because motor and shock removal do not impact alignment.

I paid for an alignment and that was not the problem. The car was still within specs. I swapped wheels side to side. No change. I do all this for a car which is under warranty? Am I the only one who thinks this is crazy? This has been ongoing for a month. The only miles I have driven the car in that time was to and from the dealer.

What can go so wrong during the work that was done that the car now reacts so violently to slight throttle input? Can you imagine doing using launch control? You would do a 90 degree turn at best.

I only have one idea left. Maybe one of the dynamic motor mounts got damaged during motor removal or install causing major weight transfer into one corner. What else could it be, any ideas?

All this brings up a much bigger question: Shouldn't the Factory Porsche Rep have been sufficiently trained to identify and diagnose this major safety issue?

 

like you suggested, it may have something to do with mounts, both engine and transmission.

How old are your tires? maybe worn out inner tire walls. Hope its sorted out soon for you!

 

if its happening at 1/4 throttle i doubt its the mounts. does this happen on all roads ? i want to believe that its tires and/or alignment but youre saying its spot on..
what happens when you slam on the brakes ?

 

My car does this when I drive on rough freeways. It's normal when you are running such wide tires. It's like I have to chase the car and steering. Lots of people have this issue.

 

My 997.1 turbos (2) and my 997.2 turbo tend to do this as the wheels/tires track the most minute groves in the road - but not to the extreme you are describing. I was able to overcome this with GMG springs and sway bars (or at least I believe this was the fix). I also have very aggressive alignments and 19 inch wheels. That being said, on a perfect, rubberized road the turbo did not do this much at all it would some of this on grooved pavement. If you have a good race shop locally I'd have them drive it for an opinion.

 

My 997.2 TS doesn't do this...

 

Having never mounted 20" wheels, I can't tell if this "normal" but it sure doesn't sound normal (especially since the 20" didn't pull left BEFORE the engine got dropped). Did the Porsche factory rep drive your car and experience the pull himself? Suspension, tire pressure, springs and/or rear brakes "rubbing" could all be contributing factors...

 

My 4 different 997 Turbo's have never done this. Do you have the same make of tires on the front as the rear.

 

My .2T have never done this

 

Take it to a different dealer and let them look at it.

I know this sounds stupid, but are the tires the right size? If they are mismatched left to right or something crazy like that it may cause it. Either that or it sounds like something is messed up in the rear diff or some sort of failure in the PTV system? Sending all the power to one wheel or something?

It would be interesting to know what happens under heavy braking. At least you can determine if it is the application of power causing it, or something goofy with the chassis/wheels/tires.

 

Thank you for all the comments to far.

Car went in fine. Came back a lame duck. 20s did not cause this before and I'll bet they do not now.

I don't know what parts they took out. But one or more of them got put back in wrong.

What is PTV?

 

PTV=Porsche Torque Vectoring, an option on 997.2 cars

 

Have the dealer pull a set of rims and tires off another turbo and see if the problem repeats. If not and it will not then have them fix the darn thing if its under warranty.

Its totally possible that a vector sensor got damaged by the tire shop when they swapped everything over and the car is misreading the sensor and trying to compensate.

 

I'm running 20's with 325 in the rear and never had this, and I've driven on all sorts of roads. Sounds like a problem for sure.

 

The tires were OK before. Actually handling in general was OK. This is like someone flipped a switch, put a part in wrong way, or killed some sensor.

PTV failure of some kind makes the most sense since it only happens when there is throttle input.

Where are those sensors?

Braking is OK.