GT3 pulls to the right under acceleration...thoughts?
07-03-2013, 10:00 AM
#16
I had a milder version of this problem with my GT3. The car was freshly aligned and balanced, took it out for a test drive and it "twisted" under power and pulled to one side. It was diagnosed as sway bar preload.
07-03-2013, 12:52 PM
#17
Rennlist Member
Problem is, this just started a couple weeks ago. been fine until then.
And now that I say the 700 miles, it's more. took a trip last month up to the Tail of the Dragon and put over 500 miles just that day on it. Ran perfect. Wife started noticing that the car felt funny and thought the alignment was off. I took it over to get it checked, and it's all the same as before.
And when I say pulls, I mean hard. Step hard on the gas and it will change lanes. Let off and it straightens out. Again, I thought it was an alignment issue thinking it was just tracking all over the place, only until I really paid attention did I notice is was when you touch the throttle.
I'll get it on a lift next week (Leaving for Mid Ohio Club Race tomorrow night) and see if anything is loose or broken.
And now that I say the 700 miles, it's more. took a trip last month up to the Tail of the Dragon and put over 500 miles just that day on it. Ran perfect. Wife started noticing that the car felt funny and thought the alignment was off. I took it over to get it checked, and it's all the same as before.
And when I say pulls, I mean hard. Step hard on the gas and it will change lanes. Let off and it straightens out. Again, I thought it was an alignment issue thinking it was just tracking all over the place, only until I really paid attention did I notice is was when you touch the throttle.
I'll get it on a lift next week (Leaving for Mid Ohio Club Race tomorrow night) and see if anything is loose or broken.
On my old 996, I had a nut that worked loose over time (rear lower control arm to upright), and the ball joint pin didn't break free from the upright until I hit a bump in the road. After that, my car experienced similar symptoms, as there was nearly a half inch of play at that connection under various loading conditions.
07-03-2013, 04:50 PM
#18
Nordschleife Master
Definitely check all your suspension nuts and bolts...
On my old 996, I had a nut that worked loose over time (rear lower control arm to upright), and the ball joint pin didn't break free from the upright until I hit a bump in the road. After that, my car experienced similar symptoms, as there was nearly a half inch of play at that connection under various loading conditions.
On my old 996, I had a nut that worked loose over time (rear lower control arm to upright), and the ball joint pin didn't break free from the upright until I hit a bump in the road. After that, my car experienced similar symptoms, as there was nearly a half inch of play at that connection under various loading conditions.
07-04-2013, 11:29 AM
#23
Racer
Are the rear tires the exact same spec ?
I had to replace the corsas on the rear of my 575. OOS everywhere and had to use one N spec and one normal.
Exhibited the same systems
I had to replace the corsas on the rear of my 575. OOS everywhere and had to use one N spec and one normal.
Exhibited the same systems
07-06-2013, 12:03 AM
#25
This happened to me at the track when I "lost" the rubber on the inside of my tire. It was an older set of tires and an entire ring of rubber failed around the tire (in one piece). The tire held air but the different resultant diameter resulted in the car pulling to one side during acceleration.
07-06-2013, 12:05 PM
#26
Easy quick test, swap your rear wheels from side to side and see if the pull follows the tires. If so, you know it is the tires. If not, check the alignment and finally the diff. Even if the diff clutches start to go, it won't just pull to a side under acceleration.
I had a similar problem on the my GT3 and we found my new rear tires at the time were mismatched. Both the same tire size, tread pattern, approximate MFG date and N rating. One had a different a different load rating. Getting it swapped with one with the same load rating fixed the problem. It would pull one direction under acceleration and the other under braking.
I had a similar problem on the my GT3 and we found my new rear tires at the time were mismatched. Both the same tire size, tread pattern, approximate MFG date and N rating. One had a different a different load rating. Getting it swapped with one with the same load rating fixed the problem. It would pull one direction under acceleration and the other under braking.
07-06-2013, 12:10 PM
#27
Nordschleife Master
Have you swapped right side (F&R) to left side to see if it still does the same thing. Had it happen to me with brand new tires and the it turned out one rear was a defective tire. If you swap and replicate the to the other side, tires would be the culprit. If not, then I would probably narrow it to either toe change (only a few places on the toe arm to fail) or LSD shot.
Easy quick test, swap your rear wheels from side to side and see if the pull follows the tires. If so, you know it is the tires. If not, check the alignment and finally the diff. Even if the diff clutches start to go, it won't just pull to a side under acceleration.
I had a similar problem on the my GT3 and we found my new rear tires at the time were mismatched. Both the same tire size, tread pattern, approximate MFG date and N rating. One had a different a different load rating. Getting it swapped with one with the same load rating fixed the problem. It would pull one direction under acceleration and the other under braking.
I had a similar problem on the my GT3 and we found my new rear tires at the time were mismatched. Both the same tire size, tread pattern, approximate MFG date and N rating. One had a different a different load rating. Getting it swapped with one with the same load rating fixed the problem. It would pull one direction under acceleration and the other under braking.
07-07-2013, 01:42 PM
#28
Racer
Easy quick test, swap your rear wheels from side to side and see if the pull follows the tires. If so, you know it is the tires. If not, check the alignment and finally the diff. Even if the diff clutches start to go, it won't just pull to a side under acceleration.
I had a similar problem on the my GT3 and we found my new rear tires at the time were mismatched. Both the same tire size, tread pattern, approximate MFG date and N rating. One had a different a different load rating. Getting it swapped with one with the same load rating fixed the problem. It would pull one direction under acceleration and the other under braking.
I had a similar problem on the my GT3 and we found my new rear tires at the time were mismatched. Both the same tire size, tread pattern, approximate MFG date and N rating. One had a different a different load rating. Getting it swapped with one with the same load rating fixed the problem. It would pull one direction under acceleration and the other under braking.
07-15-2013, 12:49 PM
#29
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BTW - I recently installed your old front PS2s with a set of new rears. The tires are great! Thanks again.
Cheers
Jim
07-15-2013, 01:59 PM
#30
Rennlist Member
if you have stock bushings in rear suspension arms - undo them all and check for play. one of reasons I run all solid steel joints/mounts on my car is to have easy visual control of all joints.
one of reasons when your car goes in straight line with no load it means you may have some dynamic changes in rear axle under load. either toe changes or some mounts move. good thing - it is very easy to take this suspension apart, just do not forget to use Loctite when you put it back together and use red paint/nailpolish to mark positions of all nuts and bolts.
one of reasons when your car goes in straight line with no load it means you may have some dynamic changes in rear axle under load. either toe changes or some mounts move. good thing - it is very easy to take this suspension apart, just do not forget to use Loctite when you put it back together and use red paint/nailpolish to mark positions of all nuts and bolts.
