dart.deanda

I went to Gulfport Drag Strip tonight. First time 1/4 mile-ing my C6Z. I hit a 12.6@119 with a 2.3 60 foot. My best mph was 122. Problem was I am still spinning like crazy on the MPSS. I know I should get some drag radials. I just wanted to get a baseline number, so now I have that.

Something weird was going on though. I would spin, come out of the throttle, go back in and the car was jerking side to side in the high RPMs in 2nd and 3rd. It was pretty bad. Bad enough that I could not wind out the gears every time without fear that I was going to lose control. I was down to 26 psi, so I came up to 28, and finally 30. I am running 345s in the rear, and 285s up front. I had the fronts at 37 psi. I was running with traction control off, but even with it on once, it did the same thing. It seemed to get better some with more pressure in the tires. It happened in both lanes.

It runs smooth as a baby on the street, has never done anything like that. But, the car can be a bit squirrely if the road is bad (it will catch/stay in grooves and then come out hard). I thought that was just the tires. I am thinking it could be an alignment issue, or possibly a bad suspension part somewhere. Bottom line I am done for the season if I can't figure this out quickly and parsimoniously...

ratomicZ06

Youre not the only one. This just posted.
https://www.corvetteforum.com/forums/c6-z06-discussion/3703772-new-n-a-track-times-new-post.html

Go to today's posts. Im covering this bc ive been trying to go to track for first time and every friday it rains.

rio95

I've had this with my mpss in fourth gear and last night had the same issue with my Hoosiers on one run. Check this out.

Pinski 1

I had same problem with my MPSS's.... Try a different set of tires. I did and my problems went away..

Les

I had it happen with my MPSS tires too. It felt like the car was tiptoeing from side to side under full throttle, even towards the top of 1st gear and at higher speeds under throttle. I was prepared to work with Americas Tire (where I bought them) on an exchange for some new ones.

I decided to check the balance on them first so I could eliminate that possibility. They found one wheel off by an ounce and said that would be enough to feel. I haven't been able to take a full run through 4 gears but I have run it twice through 3 gears under full throttle and I'm not feeling the problem anymore.

This kind of makes sense in my case because I had made several runs to 140+ MPH on these tires during exhibition races against an airplane and it was fine. Then on my last run, at 140 MPH it felt like a big gust of wind had hit the car from the side and from then on I had the wobble.

I hadn't connected the dots until recently because there was a big gap between that event and the next time I ran it that way. I suspect that what I felt that day was the wheel going out of balance when it was throwing a weight at high speed.

dart.deanda

Thanks Les, Pinski1 and Rio95! I'll go have all the tires balanced. Cheers! d'Art

QuickZoh6

You most likely need a *good* alignment...I've been down this road many times with the same characteristics as rio95's video.

dart.deanda

Thanks QuickZoh6, I have a pretty good tire shop local, will see if they can set it up for drags.

BREAK BREAK

Anyone think that lowering the car can cause this behavior? Mine appears lowered, I have not made any adjustments since purchasing, but the MPSS 285/345s fill up the wheel well pretty good on stock rims. I have not checked to see, but I will have the tire shop restore to stock height if so.

TRSCobra

I've got 285/345 MPSS on my lowered-on-stock-bolts 2006 Z06, and I've taken it to 120 with no issues. Immediately after lowering the car, I had the MPSS put on and the car aligned to Pfadt preformance street settings. Since then I've taken it up to 160 at a half mile event and it didn't have any wobble, shaking, etc, but that was on my RTS drag pack.