When I make a hard shift into 2nd and even 3rd with my M6 I get teeth rattling wheel hop on occasion. Any suggestions as to what causes this and how I can correct it?

Tire preassure? Miles on the car? Any mods?

No mods, 5600 miles. 245/40Z18 Azenis at 40 psi

auto? location? usual air temp?

I've been wondering about this also.

'04 or '05? If the car is an '04 there is a TSB which entails installing an isolator bushing to reduce the wheelhop. The situation involved with the TSB was rectified for the '05s.

I know I'm gonna catch hell for this one but...TSB?

It's a 6 speed and the weather is in the 90's on smooth, clean asphalt. It's also an '05. I don't want to put a dime into power mods till I know I can put the power on the ground

Originally posted by 04GOATGERM@Jul 29 2005, 02:07 PM
I know I'm gonna catch hell for this one but...TSB?
Technical service bulletin


You may want to reduce the tire preassure down to 35 and see if it helps at all.

Originally posted by Nocturn+Jul 29 2005, 04:03 PM--></div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (Nocturn @ Jul 29 2005, 04:03 PM)</td></tr><tr><td id='QUOTE'> <!--QuoteBegin-04GOATGERM@Jul 29 2005, 02:07 PM
I know I'm gonna catch hell for this one but...TSB?
Technical service bulletin


You may want to reduce the tire preassure down to 35 and see if it helps at all. [/b][/quote]
Thanks, I'll give that a shot. :)

Try to get the tire pressure where it belongs first.

GTOs are bad for this with the IRS. I put a heavy duty sway bar on, and it eliminated mine completely. SLP set on the tightest setting.

40 series tires are tough to deal with on acceleration. There is minimal sidewall flex (the whole purpose of the wheel/tire combo) and hence little absorption of harmonic oscillations.

Try playing with pressure first (as advised above) and go the suspension route if you can't get satisfaction otherwise.

All cars are a compromise. IRS is tricky, and you've altered the original engineering intent by changing wheel/tire sizes and perhaps circumference. Make sure you really know what you're doing if you mess with the IRS.

A higher rate rear spring and more rear swaybar will help a lot, I have also noticed that stickier tires make a big difference.

Changing tire pressure seems to have made the difference for now. I'll have to keep an eye on things when I make other mods.

Also just remember that dropping tire pressures are good for traction on the track but inflate them back up to the suggested pressure for normal or extended driving. As well as shorter tread life with your 40 series tire you would have to worry more about hitting a pothole or road hazard and bending your rim with a lowered tire pressure. Just a thought. :)

Well they were at 40PSI to begin with, so dropping them down to 35 wouldn't hurt much I dont think as that is about average.

I was thinking more along the lines of down to 25 or 30 psi at the track. ;)

For track usage I'm going to bite the bullet and get another set of wheels with sticky tires. Any suggestions on something that would be drivable to and from the track?

How about the bushing sets that you can buy. Do they cure wheel hop?


See Link Here (http://www.gravanatuning.com/applications/2004_Pontiac_GTO_5.7.aspx/0/2924/_Bushings_Prothane_Control_Arm_Kit_Rear_)

Originally posted by appletonrc@Aug 9 2005, 12:32 PM
How about the bushing sets that you can buy. Do they cure wheel hop?


See Link Here (http://www.gravanatuning.com/applications/2004_Pontiac_GTO_5.7.aspx/0/2924/_Bushings_Prothane_Control_Arm_Kit_Rear_)
No, bushing by themself will not cure wheel hop. It takes a bunch of mods including bushings, shocks, sway bars, diff cover, etc to really elliminate wheel hop (very expensive and not for most). These mods usually come with a decreased ride quaility with an increase in noise.


I've found the best way to deal with wheel hop is learning how to launch the car gently and smoothly. The GTO doesn' t like high rpm jerkly launches. It also doesn't like much gas applied during clutch release. These things seem to always create wheel hop.

The way I've found to get off the line fast without wheel hop is
Rev to about 2700 rpms. Then quickly and smoothly let out the clutch (without applying anymore gas) Then when you have just about completely released the clutch
(near the top) start getting into the gas (don't floor the gas all at once - smoothly apply the gas until you get it to the floor).
It's all happens fast and takes a little practice to get it right. If you get into the gas too soon or too hard you will generate wheel hop.

This is also similar to the technique they used in High Performance Pontiac to run some pretty good 60' times in an 06 M6 GTO. The basically said they didn't apply any gas as they were letting out the clutch. They found the right rpm to release the clutch. Then after clutch release they got into the gas. Very similar to what I do. I just get into the gas a little sooner (near the end of the clutch release).

Well the guy was getting it during shifts, and bushing by themselves wont elimnate wheel hop but they can reduce it greatly by allowing the suspension to absoarb forces better. The CTS-V guys have been experimenting with them because they have it worse than anyone.

As my technique has improved the wheel hop has all but disappeared. I got some more pointers from the test of an '05 GTo in GM High Tech High Performance.

[QUOTE]the word is the nitto 555 drag radials in the 245-45-17(factory size) are some of the best value....any word from others who have used them? :ph34r:

Originally posted by Nocturn@Sep 3 2005, 07:02 PM
Well the guy was getting it during shifts, and bushing by themselves wont elimnate wheel hop but they can reduce it greatly by allowing the suspension to absoarb forces better. The CTS-V guys have been experimenting with them because they have it worse than anyone.
I agree - poly X member bushings helped mine a bit - konis helped a little more - but I still have some hop. Looking at springs next as TEK said. Mine is an 04/A4