Question for Luke P. at Tire Rack re 2008 Viper Tires . . .

[rcl4668]

Luke --

If you get a chance, can you answer this question? The Road and Track website has the following statement about the Michelin Pilot Sport PS2 tireson the new 2008 Viper:

"What really helps hook up the engine room's thunder are the new Michelin PS2 tires molded with a Pilot Cup race compound, unique rubber created specifically for this new Viper."

Is this accurate? I believe you or someone else on this board posted previouly that the version of the PS2 on the 08 Viper is in fact different than the "regular" version. Can you shed some light on the differences? Thanks.

/Rich

[Kai SRT10]

This information came from one of the SRT engineers during the tech chat session. He said that the Viper tires were better than the aftermarket PS2 tires.
He didn't say how they were different, just that they were better.

Here is the quote:

Originally Posted by srtengineers
We recommend staying witht the PS1 runflats on the '03-'06 car. The tuning is designed around those tires. The suspension on the '08 Viper has been reworked around the PS2 non-runflat. Also, the '08 Viper spec PS2 is NOT the same as the current aftermarket PS2 available from Michelin. The Viper version of the PS2 is way more kickass. BTW, Michelin plans on making the Viper spec PS1 runflat through 2012 for you guys.

Originally Posted by rcl4668

Luke --

If you get a chance, can you answer this question? The Road and Track website has the following statement about the Michelin Pilot Sport PS2 tireson the new 2008 Viper:

"What really helps hook up the engine room's thunder are the new Michelin PS2 tires molded with a Pilot Cup race compound, unique rubber created specifically for this new Viper."

Is this accurate? I believe you or someone else on this board posted previouly that the version of the PS2 on the 08 Viper is in fact different than the "regular" version. Can you shed some light on the differences? Thanks.

/Rich

[rcl4668]

Originally Posted by Kai SRT10

This information came from one of the SRT engineers during the tech chat session. He said that the Viper tires were better than the aftermarket PS2 tires.
He didn't say how they were different, just that they were better.

Here is the quote:

Originally Posted by srtengineers
We recommend staying witht the PS1 runflats on the '03-'06 car. The tuning is designed around those tires. The suspension on the '08 Viper has been reworked around the PS2 non-runflat. Also, the '08 Viper spec PS2 is NOT the same as the current aftermarket PS2 available from Michelin. The Viper version of the PS2 is way more kickass. BTW, Michelin plans on making the Viper spec PS1 runflat through 2012 for you guys.

Kai --

I recall that comment and others on this forum as well. I guess what I am trying to pin down is the meaning of the phrase "way more kickass." Is this a difference in tire construction, tread pattern, tread compound (as suggested by R&T and Edmunds) or a combination thereof?

/Rich

[SylvanSRT]

i believe that all Viper sized(stock) have the same compound(ie; there are not two compounds for the same tire size for the stock Viper size PS2). Pilot Sport and PS2's are considered to be a race compound tire(with tread that is)

[GR8_ASP]

I may be wrong but I thought PS/2 tires had the same compounds as Sport Cups. Thta is 2 different compounds for the inside and outside regions.

Luke can you clear this up as well as th ecomment about PS/2 in Gen III size being different. The front size is common so I have a hard time believing that Michelin would make 2 unique tires of the same name and size. The rears are 19 inch versus 18 inch and offer some more potential.

[black mamba1]

When the SRT engineers visited our site some months back they mentioned that the PS2's we are buying are not the same ones that are on the 08. So this should come as no surprise. They mentioned that the ones on the 08 were designed specifically for the 08 Viper by Michelin, and were not available back this summer or this past spring or winter.

[Lee00blacksilverGTS]

I moved this over here with permanent redirect as I think Luke might actually see it here and comment.

[Luke@tirerack]

while the PS2 for the 2008 Viper is different than the standard PS2 and Michelin will not tell us what the exact differences are they and the Dodge guys thought up but, lets look at the facts:

PS2 C1 (Viper OE)
UTQG...................... 220 AA A
Service Description....... (105Y)
Tire Tread Type........... ASY
OE Designations........... C1
Tread Depth............... 10/32nds.
Rim Protector............. YES
Country of Origin......... USA
Tire Construction:
Belt.............. 2 STEEL
Sidewall.......... 1 RAYON
Reinforcement..... 1 POLYAMIDE

Standard PS2
UTQG...................... 220 AA A
Service Description....... 98Y
Tire Tread Type........... ASY
OE Designations........... NONE
Tread Depth............... 09/32nds.
Rim Protector............. YES
Country of Origin......... USA
Tire Construction:
Belt.............. 2 STEEL
Sidewall.......... 1 RAYON
Reinforcement..... 1 POLYAMIDE

now ... here's what the published specs tell us

the belt package and constuction materials is the same on both tires
UTQG is the same
Tread design is similar
speed rating is different Viper = (Y) non-Viper = Y
tread depth is different

when looking at the differences in tire specs you can determine many things like that there is an internal carcass difference which gives it a higher speed rating ... but the question at hand was regarding Sport Cup rubber compound in the Viper OE tire ... A Sport Cup UTQG is 80 and both PS2's are 220 so, I seriously doubt the rumors since the wear numbers are so dramatically different.

Also, a Michelin test driver competed in One Lap of America last year in a Viper and ran normal PS2's not the Viper Specific version. Given his position, knowledge, connections and the competitive nature of the event I do not think he would be willing to leave any possible advantage on the table

so, in an educated guess the answer is yes they are different but, no they do not use Sport Cup rubber compound.

[rcl4668]

Thanks Luke!

/Rich

[GR8_ASP]

Luke check out page 94 in Road and Track. Here is what it says:

"A big change that has drastically affected the Viper's ride and handling is an upgrade from the run-flat Michelin Pilot Sports to a new, custom tire. Labeled as Pilot Sport PS2s, they are actually made specifically for the Viper with Michelin's more aggressive "R" compound from the Pilot Sport Cup tire."

So are you saying that it is not true? Can we find out from Michelin?

My specific question is can we use the fronts that are Viper specific (if there are any) and use the 18" non-Viper specific rears. Or is that a bad match?

[Luke@tirerack]

the following statement has been confirmed by Michelin
-------------------------------------------------------------------------------------------------------------------------------
The road test report on the 2008 Dodge Viper SRT10 Coupe in the October issue of Road & Track magazine states,

Originally Posted by Road & Track

A big change that has drastically affected the Viper's ride and handling is an upgrade from the run-flat Michelin Pilot Sport to a new, custom tire. Labeled as the Michelin Pilot Sport PS2, they are actually made for the Viper with Michelin's more aggressive "R" compound from the Pilot Sport Cup tire.

Unfortunately this is only partially correct.

Michelin has developed a Pilot Sport PS2 for the 2008 Viper SRT10 (much like they have tuned other Pilot Sport PS2 tires specifically for BMW M-Series, Ferrari and the Porsche Carrera GT models). Like other Pilot Sport PS2 tires, the Viper tires features the asymmetric tread design, side-by-side dual tread compounds and variable contact patch to provide the desired traction and handling.

However the Pilot Sport PS2 for the 2008 Viper does not feature the more aggressive "R" compound from the Pilot Sport Cup tire which, while capable of providing more dry road traction, would also significantly reduce tread life.

Therefore the big change that improved the 2008 Viper's ride and handling is the upgrade to the new Pilot Sport PS2 tires from the run-flat Michelin Pilot Sport ZP (used on earlier 2003-2007 model year cars) that featured a firmer, heavier run-flat construction, a directional tread design and a single tread compound.

Since we have just begun receiving the new Viper front Pilot Sport PS2 tires, we now have the opportunity to replace the original equipment tires on the 2008 model year cars, as well as help Viper drivers upgrade their 2003-2007 model year cars to the new tires.

Pilot Sport PS2 tires should not be mixed with Pilot Sport ZP run-flat tires in any combination!
--------------------------------------------------------------------------------------------------------------------------------

in other, easier to understand, words the biggest part of the performance improvement is due to the elimination of the use of run-flat tires.

We have seen for years that cars originaly equipt with run-flat tires see a significant perfromance improvement when the tires are repalced with top quality performance tires ... just ask any of your Corvette owning friends who have been dealing with runflat tires since the mid-nineties

[rcdice]

Luke,

Is it possible to order PS2's, in Viper sizes, WITH the R sport cup compound?

I understand they are not OEM on the 08 but do they exist?

Thanks,

[rcl4668]

Originally Posted by Luke@tirerack

the following statement has been confirmed by Michelin
-------------------------------------------------------------------------------------------------------------------------------
The road test report on the 2008 Dodge Viper SRT10 Coupe in the October issue of Road & Track magazine states,

Unfortunately this is only partially correct.

Michelin has developed a Pilot Sport PS2 for the 2008 Viper SRT10 (much like they have tuned other Pilot Sport PS2 tires specifically for BMW M-Series, Ferrari and the Porsche Carrera GT models). Like other Pilot Sport PS2 tires, the Viper tires features the asymmetric tread design, side-by-side dual tread compounds and variable contact patch to provide the desired traction and handling.

However the Pilot Sport PS2 for the 2008 Viper does not feature the more aggressive "R" compound from the Pilot Sport Cup tire which, while capable of providing more dry road traction, would also significantly reduce tread life.

Therefore the big change that improved the 2008 Viper's ride and handling is the upgrade to the new Pilot Sport PS2 tires from the run-flat Michelin Pilot Sport ZP (used on earlier 2003-2007 model year cars) that featured a firmer, heavier run-flat construction, a directional tread design and a single tread compound.

Since we have just begun receiving the new Viper front Pilot Sport PS2 tires, we now have the opportunity to replace the original equipment tires on the 2008 model year cars, as well as help Viper drivers upgrade their 2003-2007 model year cars to the new tires.

Pilot Sport PS2 tires should not be mixed with Pilot Sport ZP run-flat tires in any combination!
--------------------------------------------------------------------------------------------------------------------------------

in other, easier to understand, words the biggest part of the performance improvement is due to the elimination of the use of run-flat tires.

We have seen for years that cars originaly equipt with run-flat tires see a significant perfromance improvement when the tires are repalced with top quality performance tires ... just ask any of your Corvette owning friends who have been dealing with runflat tires since the mid-nineties

Thanks for the follow up Luke.

/Rich

[GR8_ASP]

Thanks Luke for cleraring this up. Looking forward to upgrading my OEM sizes next year after I prematurely wear the rears out. BTW I have been running run flats up front and PS in the rear (Pilot Sports not PS2) with no issue. More understeer propensity but otherwise ok.

[Luke@tirerack]

Originally Posted by GR8_ASP

with no issue. More understeer propensity but otherwise ok.

isn't that an issue ... if not normally it certainly would be in an emergency manuever