PDA

View Full Version : Question: Grand Sport Gen 2 tire chatter



jefflohss00
02-17-11, 09:45 PM
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
02-19-11, 08:33 PM
Would be interested in replies too, since just ordered new 2011 GS Conv today.:cool

Johnduck
04-13-11, 08:38 AM
I have a 2010 GS with the gen I tires and they are bad also, the colder it is the worse it is.

Tuna
04-13-11, 09:20 AM
Seems pretty normal for really wide front tires with a lot of grip. Even my CTS V does this.

BigJimZ16
04-13-11, 11:23 AM
My '10 Grand Sport Vert does the same thing. I'm almost immune to it now...

Pourboire
06-15-11, 12:23 PM
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
06-15-11, 12:49 PM
Anything is better than Gen 1s.

Tuna
06-15-11, 03:24 PM
Anything is better than Gen 1s.

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

catbert
06-16-11, 03:46 PM
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
06-16-11, 04:46 PM
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
06-20-11, 08:58 AM
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
03-21-13, 08:40 AM
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
03-21-13, 09:27 AM
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
03-21-13, 09:40 AM
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
03-21-13, 11:43 AM
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!! :thumb:thumb

Tom Martin
12-10-13, 07:06 PM
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
02-26-14, 10:59 AM
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
02-26-14, 11:07 AM
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 (http://www.thecorvettemechanic.com/forum/showthread.php?3859-14-03-10-001-Tire-Hop-Tire-Chatter-During-Tight-Turns-at-Parking-Lot-Speeds&p=16882#post16882)

ParisTNDude
11-28-14, 06:10 PM
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
11-28-14, 10:59 PM
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.

lqueral
11-29-14, 10:33 AM
That's what the Chevrolet engineer told me as well. "Heat 'em up, it won't break". Yeah, he actually said that. My concern is that massive wheel-hop can break stuff, and the wheel-hop IS massive. I was told by a Michelin rep that they will soon be releasing their all-season ultra-performance Pilot Sport AS/3 tire in a ZP (runflat) config for the Grand Sport application. I will consider this tire when the OEM's wear out, as I do not track the car, and am willing to sacrifice a tenth or two to get a friendlier tire.

lqueral
03-03-15, 07:00 PM
That's what the Chevrolet engineer told me as well. "Heat 'em up, it won't break". Yeah, he actually said that. My concern is that massive wheel-hop can break stuff, and the wheel-hop IS massive. I was told by a Michelin rep that they will soon be releasing their all-season ultra-performance Pilot Sport AS/3 tire in a ZP (runflat) config for the Grand Sport application. I will consider this tire when the OEM's wear out, as I do not track the car, and am willing to sacrifice a tenth or two to get a friendlier tire.

Update - I called Michelin yesterday (3/2/15) to find out the status of the AS/3 tire release and the guy I spoke with denied they were coming out with a Grand Sport fitment. Which either means he doesn't know or the previous guy was blowin' smoke up my dupa. The guy I spoke with yesterday didn't seem real sharp, but I think he was right, sadly. I guess not enough demand to justify production in GS sizing. This means the Michelin Pilot Sport PS2 ZP is the only Michelin in GS sizes that are ZP (run-flat). These are summer tires, just like the OEM Goodyears. Oh well.

catbert
03-04-15, 04:35 PM
Update - I called Michelin yesterday (3/2/15) to find out the status of the AS/3 tire release and the guy I spoke with denied they were coming out with a Grand Sport fitment. Which either means he doesn't know or the previous guy was blowin' smoke up my dupa. The guy I spoke with yesterday didn't seem real sharp, but I think he was right, sadly. I guess not enough demand to justify production in GS sizing. This means the Michelin Pilot Sport PS2 ZP is the only Michelin in GS sizes that are ZP (run-flat). These are summer tires, just like the OEM Goodyears. Oh well.

While "all weather" tires for a performance car like the GS and Z06 is a bit of an oxymoron, I had really good all weather performance on both my Z and GS with Bridgestone Pole Position Potenzas. They are great in the wet and slush, and waaaaay better than OEMs in Winter driving. Just a really great all-around choice.

lqueral
03-05-15, 09:17 AM
While "all weather" tires for a performance car like the GS and Z06 is a bit of an oxymoron, I had really good all weather performance on both my Z and GS with Bridgestone Pole Position Potenzas. They are great in the wet and slush, and waaaaay better than OEMs in Winter driving. Just a really great all-around choice.

I went on Tire Rack, read several reviews on the Bridgestones, and liked what I read. Also saw that the tire had a slightly higher wear index than the OEM's. At a substantial savings over what I consider the junk OEM's, I will seriously consider them as replacements. I generally am a Michelin fan, so I will likely also consider the Pilots at the higher price point. But the Bridgestones interest me.... Thanks for the tip.

kpic
03-05-15, 08:27 PM
Not exactly correct. It is called the Ackermann Effect. A man named Georg Lankensperger, a wooden wheel maker, figured out how to beat it in the early 1800s.


Lankensperger figured out how to make a pair of wheels turn smoothly in two separate arcs. You see, when you turn the steering wheel of your car all the way to the right, for example, the left or outer wheel travels in a larger circle than the right or inner wheel.

Lankensperger figured out that if the inside wheel is turned at a greater angle than the outside wheel, it won't skip over the pavement and make that thumping noise that's prevalent in the 2014 Corvette.

Corvette engineers decided the Stingray's tight turning radius is more important than eliminating the Ackermann Effect, said Chevrolet spokesman Monte Doran. It comes into play only at parking-lot speeds.
Vette's thumping rubs some drivers the wrong way (http://www.autonews.com/article/20131116/OEM03/311189992/vettes-thumping-rubs-some-drivers-the-wrong-way)

Tire size and rubber compound has nothing to do with it as it is a trick with angles. If the designer didn't want it; he would have followed Lankensperger's "trick."

It is something the designers of the Corvette chose to ignore.