I have a thumping sound come from the front of my car. The thumping sounds almost like a flat tire. I started having this problem after the December NASA event at Road Atlanta where I locked up the brakes and got a little sideways. I stayed on track and didn't hit anything. Right after this happened I started getting the thumping sound. I checked the car out and saw I had a flat spot on each of the left side tires. Recently I bought two new tires hoping that would fix my problem but it didn't. So tonight I swapped out my 6ul's for my stockers and did a test drive and the thumping sound was even worse??
I'm running a RB 1.25 FSB with Koni sports and ground controls. Any ideas what it might be?? Thanks in advance!

 

Disconnect the sway bar end links up front and drive it around. Report back if sound is gone.

 

Ok did the test drive the sound is still there??

 

Check the rubber boots on the steering rack

 

Does it seem to be related to how fast you're going? ie: increase with speed?

 

Yes it does

 

Update: Took the car to a local shop I use and they seem to think it's the tires.

 

I'm unclear on something, have you changed out all 4 wheels with ones that were NOT used at the track?

 

I had two changed out(Rs3's). I thought only two had flat spots. I checked the other two and they each have a VERY small flat spot. I would just replace the other two also but the Rs3's are on national back order. I did a test drive with the stock wheel/tires and the thumping got worse. So I took the stockers to get them balanced and just found out two of the rims are bent wtf. I knew I should've just bought four Rs3's!!!

 

Sounds like you're jumping from one problem to another without having the ability to eliminate variables. Even a flat spot that is barely visible will be felt/heard. If you were sideways and locked up, then all four were locked up. Granted the leading tires have more weight on them, meaning more friction and larger flat spots, the others will suffer as well.

Flatspots suck.