Grand Sport Grand Sport Gen 2 tire chatter

[jefflohss00]

My new 2011GS has the new generation 2 tires because it has selective ride control. When turning at slow speeds there is alot of tire chatter/slipping of the fronts. I understand that this is normal because of the tire width but am wondering if I made a poor choice and if the Gen 1 tires would have been better? I have been told that they are superior track tires but they have less tread depth and will not last as long as G1's. Opinions please.

 

[SGF]

Interested

Would be interested in replies too, since just ordered new 2011 GS Conv today.:cool

 

[Johnduck]

I have a 2010 GS with the gen I tires and they are bad also, the colder it is the worse it is.

 

[Tuna]

Seems pretty normal for really wide front tires with a lot of grip. Even my CTS V does this.

 

[BigJimZ16]

My '10 Grand Sport Vert does the same thing. I'm almost immune to it now...

 

[Pourboire]

2011 Grand Sport tires

Guys not sure about tire nomenclature, but my 2011 grand sport convertible has not exhibited anything mentioned. The car came
with Goodyear Eagle F1 tires. I monitor my g forces on the HUD when cornering and I have pushed it near 9 in some corners

 

[catbert]

Anything is better than Gen 1s.

 

[Tuna]

Anything is better than Gen 1s.

The SuperCar G2's should be better in the rain and pretty much the same when dry.

 

[catbert]

The SuperCar G2's should be better in the rain and pretty much the same when dry.

The tread looks wet friendly, but it's a Summer rated tire, so stay out of the cold and slush.

 

[Hib Halverson]

Guys not sure about tire nomenclature, but my 2011 grand sport convertible has not exhibited anything mentioned. The car came
with Goodyear Eagle F1 tires. I monitor my g forces on the HUD when cornering and I have pushed it near 9 in some corners

"...near 9..."
:L

If you were cornering at lateral acceleration of 9g, you'd also be dead because of your snapped spine.

I suspect, you meant "...near 0.9g."

But...I digress.

The OP was talking about tight turns at slow speeds not high-speed turns near the car's handling limit.

Wide, ultra-performance radials when turning sharp at slow speeds may "chatter" a bit. The severity depends on the surface, but some chatter is to be expected.

Also, if we're going to discuss...or complain, as the case might be...about Goodyear EMT tires, let's at least get our nomenclature straight.

The first generation run flat, the Eagle F1 GS-C EMT, was offered from 94-96.
The second generation RFT, the Eagle F1 GS EMT, was offered from 97-04.
The third generation Eagle F1 GS-2 EMT and the Eagle F1 Supercar EMT were introduced in 2005 and continue today.

 

[Pourboire]

Correct meant .9 G's, spent to many years flying jets and haven't gotten use to using decimal. I believe my driving experience in Arizona is completely different then most of the other states with hits moderate and hot climate.

 

[Kevs CRM Vert]

I'm glad I found this thread because I took delivery of my CRM GS vert last weekend and as I pulled out of the dealer I thought the front tires were not bolted on. I have never had a feeling like this in a car. Glad to see it is normal.

Do the Michelin Pilots exhibit this?
Has anyone had good or bad experience with the Michelin tires? I love them on my sedans (usually Energy MVX series).

 

[Tuna]

I'm glad I found this thread because I took delivery of my CRM GS vert last weekend and as I pulled out of the dealer I thought the front tires were not bolted on. I have never had a feeling like this in a car. Glad to see it is normal.

Do the Michelin Pilots exhibit this?
Has anyone had good or bad experience with the Michelin tires? I love them on my sedans (usually Energy MVX series).

Michelin Pilot Sports and Goodyear tires do this.
Both my Vette and my CTS V have Pilot Sport tires. When it's cold out and I'm backing slowly with the steering near lock, the front tires "chatter" as they grab and break loose.

First time I noticed this was on my 2004 CTS V with the GY F1 SuperCar tires. Got my attention.
After changing to GY F1 D3 tires, I didn't notice it as much on the V1.
My CTS V2 came with Michelin PS2s and they do the same thing when it's cold out.
My 427 Vert does the same thing and it has Michelin PS2.

 

[Hib Halverson]

Pilot Sports do it. The F1 Supercars on my C5Z do it sometimes.

In fact, any wide tire, with a soft tread compound and a tread design which has limited or no grooves with very large, stiff tread blocks will chatter at slow speed in sharp turns.

It chatters because in a turn like that the actual distance traveled by the inside and the outside of the tread is different. Something has to give in that situation so part of the tread suddenly breaks loose and sort of "jumps ahead or behind" and that's the chatter you feel and hear.

 

[BigJimZ16]

Pilot Sports do it. The F1 Supercars on my C5Z do it sometimes.

In fact, any wide tire, with a soft tread compound and a tread design which has limited or no grooves with very large, stiff tread blocks will chatter at slow speed in sharp turns.

It chatters because in a turn like that the actual distance traveled by the inside and the outside of the tread is different. Something has to give in that situation so part of the tread suddenly breaks loose and sort of "jumps ahead or behind" and that's the chatter you feel and hear.

Nice explanation Hib!!

 

[Tom Martin]

Tire chatter

I have a huge problem with tire "chatter". I took my 2012 GS back to the dealer to have them drive it when the air temp and the tires (Michelin) are cold. They said the same thing as the responses here in the forum. They even attached a bulliten from GM stating the same thing. Besides the "chattering" my tires don't stick anywhere near as well in cold temps. All performance tires stop sticking at below about 40 degrees. Want to spin out in a hurry? Just push your car too hard in cold temps. My BMW has snow tires on it and my Vette's in the garage waiting for spring.

 

[lqueral]

cold sucks

I have a huge problem with tire "chatter". I took my 2012 GS back to the dealer to have them drive it when the air temp and the tires (Michelin) are cold. They said the same thing as the responses here in the forum. They even attached a bulliten from GM stating the same thing. Besides the "chattering" my tires don't stick anywhere near as well in cold temps. All performance tires stop sticking at below about 40 degrees. .

I find at less than 60 degrees I can't floor the gas pedal in 1st or 2nd gear and not make the back end hop around. I don't know why the traction/control aids are not preventing the wheelspin, and both nannies are "on". I don't trust the car in less than 60 degrees. At, say, 75 or 80 degrees, doing the same things brings a little tire spin and then hookup and fierce acceleration. I don't drive the car between Thanksgiving and end of March, but April and October have some beautiful 55 or 60 degree days and I have to use extreme caution. My 1996 LT4 was not nearly so slippery either with the OEM Goodyear GS-C's or the Firestones I put on towards the end of my ownership. Both of those tires were considered Ultra Performance Summer, but that car had over 100HP less. I cannot even comprehend how Z06's and ZR1's fare in cooler weather. They must be rolling coffins.

 

[c4c5specialist]

HI there,

This TSB may be of interest to all here.

This is now a better reasoning, including diagrams to illustrate what Hib and others have explained.

This was released recently to address C7 and back builds to GS and ZO6/ZR1

Allthebest, Paul

#14-03-10-001: Tire Hop / Tire Chatter During Tight Turns at Parking Lot Speeds

 

[ParisTNDude]

Danged glad I read this thread. I was a day or two away from taking my car to the dealership to find out what is going on. It felt much like trying to turn hard in a 4X4 with the wheels locked in. Thanks to all for clearing this mysterious issue up.

 

[Hib Halverson]

I find at less than 60 degrees I can't floor the gas pedal in 1st or 2nd gear and not make the back end hop around. I don't know why the traction/control aids are not preventing the wheelspin, and both nannies are "on". I don't trust the car in less than 60 degrees. At, say, 75 or 80 degrees, doing the same things brings a little tire spin and then hookup and fierce acceleration. I don't drive the car between Thanksgiving and end of March, but April and October have some beautiful 55 or 60 degree days and I have to use extreme caution. My 1996 LT4 was not nearly so slippery either with the OEM Goodyear GS-C's or the Firestones I put on towards the end of my ownership. Both of those tires were considered Ultra Performance Summer, but that car had over 100HP less. I cannot even comprehend how Z06's and ZR1's fare in cooler weather. They must be rolling coffins.

If want better traction in weather below 60°, you need to either find some all-season tires or, better yet, winter tires, in the C6 GS sizes.

As far as "flooring" the gas in 1st or 2nd, it's all in tire temperature.

Learn how to do a drag race burnout before you floor it in 1st and I guarantee the car will hook.