Let's talk track tires for the Gen V!

[VENOM V]

Tires can make or break a car's lap time, and it is the one area of the Viper program that lags all of its serious competitors. Here are a few of my opinions based on tracking and discussions with track rats. I'd like to know what others think. Imagine if SRT surprised us with a new-generation hardcore R compound on the TA 2.0 or upcoming ACR?

ZR1's MPSC RUNFLATS:

I keep hearing about how phenomenal the special-construction ZR1 run flat MPSCs are from the most reliable sources. Ralph stated that they are something like 2 seconds faster than the Corsas at Laguna Seca and Erich Heuschle confirmed this to me personally. He said that the Viper "loves" these MPSCs, they made a custom set of Viper wheels in ZR1 sizing and found these gains.

And last weekend I tracked my Camaro at Buttonwillow with a local hot shoe, one of the best drivers I've ever known. He said two things that surprised me.

First, his brother drives a black C6 Z06 race car and has run a best time of 1:44 on those special ZR1 MPSCs. His best on Hoosier R6's? 1:51. He is faster on the cups! This delta I find hard to believe but these guys are two of the fastest and their words carry credibility. While I question whether they are better than R6s, this is a confirmation of how amazing the outgoing ZR1's tires were.

MPSC2s:

Second, he runs a highly modded C7 on MPSC2s. He runs these tires because he can't go to a lower treadwear for his racing class. He says they aren't as good as the ZR1 MPSCs. Also very interesting but doesn't completely surpise because of the MPSC2's 180 treadwear rating. If you're curious about these Vettes and their drivers, click the Buttonwillow link in my signature.

So the ZR1's MPSCs are the real deal, better than the Corsas. They are NOT the same tire as the MPSCs that come in Viper sizes, they are much better and were specifically developed for the ZR1 although they clearly work well on a similar car, the Viper. This was also confirmed by Erich. This jives with my personal experience where I found the regular MPSCs not as grippy or long lasting as the Corsas.

CORSAs:

A good entry-level R compound but not at the same level as the ZR1 MPSC, and certainly not in the same zip code as the Trofeo R. They are a good streetable compromise that have decent grip, last a long time, don't heat cycle out much, and can be driven in the rain. A "sensible" compromise for a performance OEM tire but not worthy of being paired with a track focused Viper such as a TA or ACR.

TROFEO R:

I'm a Camaro guy as well as a Viper guy, but anyone that doesn't believe that a huge contributor to the Z/28's remarkable lap times is due to the Trofeo Rs is a Koolaid drinker. They are likely the best R compound out there short of Hoosiers.

I asked Maurice to press Pirelli to give us Trofeo Rs on the Viper, during his recent discussions with them on the VOA discount. They already make our front size, all we need is a 345 or 355/30-19 out back to literally shave two or three seconds off of lap times! Their response? We'd love to but unfortunately can't justify the development cost considering the low volume. Which begs the question, why didn't they develop the Trofeo R for the Viper in the first place instead of the Corsa? My guess is that Chrysler's lawyers wanted a safer rain tire and chose the Corsa, but who knows.

HOOSIERS:

The new generation of Hoosier R7 and A7s are supposed to be phenomenal. I've driven both R6s and A6s on both my Viper and Camaro and they are unbelievable, so improving on them is something that I cannot wait to experience.

Crazy idea: they showed the ACR concept with Hoosiers at SEMA. How about an optional second set of track-focused wheels with Hoosier R7s that can be ordered with your TA 2.0 or ACR? The mag rags would go nuts, test them in every imaginable way and enjoy all of the controversy. Talk about press for the Viper! It would probably never happen, LOL.

I think that the Viper must have a new generation R compound if it is to remain relevant, set lap records and not fall behind the competition in the near future. Every legitimate competitor has gone to a new R compound, team Viper needs to find a way to make this happen.

[Nine Ball]

I have a set of ZR1 stock wheels/tires in my shop. My only gripe is that they are 19/20. Even the C7Z is 19/20 from the factory. They could have easily went 19/19 on both cars and saved some rotating mass and got more sidewall. Even the Z/28 went to 19/19, instead of the normal 20/20 SS.

[J TNT]

Great info Venom V , Looking forward to other response's .

[Dman]

It says a lot about the gen5 that the most limiting factor in furthering it's domination to an ultimate level is down to the tires ... and a real shame, since it's mostly about the new lineage involved. Thanks so much for the info from such trusted sources.

[VENOM V]

I have a set of ZR1 stock wheels/tires in my shop. My only gripe is that they are 19/20. Even the C7Z is 19/20 from the factory. They could have easily went 19/19 on both cars and saved some rotating mass and got more sidewall. Even the Z/28 went to 19/19, instead of the normal 20/20 SS.

My ideal setup would be 18x11 front with 315s and 19x13 rear with 345s or 355s in the offsets that you came up with for Forgeline, Tony. Kick ass performance and good looks! Love my Forgelines.

[Viktimize]

I mentioned this back when MT tested the TA and snatched the lap record by a mere few tenths. I thought it was pretty amazing that the TA could run faster than the ACR with tires that aren't in the same class. Put those MPSC's on the TA and see what kind of lap times they can ring out then.

[TrackAire]

Nice write up Todd!! How I wish they made the Nitto NT01's in a Viper size.......great wear, decent grip and very predictable.

I don't mean disrespect to the driver of the Z06, but I find it very hard to believe there would be a 7 second difference between the ZR1 MPSC's and R6's if they are both fresh, same temps, same track conditions, similar car set up, etc. It just does not add up.

I know Flatout had the Toyo R888's on his car for COTA, it would be interesting to see what kind of lap times the R888's would produce versus the cup tires or the R6's.

Since the VOA seems pretty damn successful, I'd think they can sponsor the following test:

1. Get some track time at Thunderhill (like an afternoon)

2. Acquire a set of all the top name tires mounted on a set of wheels (Toyo, Hoosiers, Corsa's, Sport Cups, etc)

3. Have 4 or 5 Viper owners who track a lot donate their time to run laps with each of the different tires and record lap times, tire wear and drivers opinions. Swap tires back and forth and use the tracks transponder timing system to record the data. Vehicle on board data systems (like Aim solo) can also be used to add more results such as corner speed, G-force, etc.

4. Document the test Vipers alignment settings before the start of the test.

This would make a great article for Viper Quarterly plus it could be video'd and put on youtube for the world to see (mainly make the PCA and Corvette clubs envious, lol).

There are a lot of us that would be willing to help during the event (not just driving chores) to make this successful.

Cheers,
George

[Vprbite]

Great write up. Very well done. Thank you, Venom. It is a definite shame that our choices are limited due to "Viper Size."

Are those ZR MPSC's too small for our needs? Though a good tire, do they just not make them wide enough? Wouldn't 18's all around help with tire selection? Though will they not fit over the Gen V brakes?

[Nine Ball]

Great write up. Very well done. Thank you, Venom. It is a definite shame that our choices are limited due to "Viper Size."

Are those ZR MPSC's too small for our needs? Though a good tire, do they just not make them wide enough? Wouldn't 18's all around help with tire selection? Though will they not fit over the Gen V brakes?

Some 18s clear the rear no problem. I even got 17s to fit on the rear of a TA, without modification. But, the wheels are not cheap. They require some deep forgings, built to my specs.

Tony

[VENOM V]

Hi George,

I hear you, Nitto NTO1s are awesome tires. Grippy all the way to cord. The new Toyo R888Rs will be out soon, likey still in Viper sizes. Hopefully they'll match or beat the NT01s, a tall order.

I totally agree about the R6s Vs. MPSCs. He has so much time on the MPSCs that my guess is that he just hadn't gotten a rythm with the Hoosiers The takeaway for me was that if a car can run a 1:44 on ZR1 MPSCS, it is a remarkable tire. The only other guy I've personally seen run that fast at Buttonwillow was Ross Murray in a Comp Coupe on Hoosiers.

I don't just like your tire test idea, I love it! I could see a way to make it economical. For example I would spring for a new set of Hoosier R7 or A7s and others could buy their choice. Lots of issues to resolve but it could work. We may want to consider Buttonwillow as its central location would make it easy for top drivers like Ross and Jonathan "Redsled" participate, perhaps with support from Dan Cragin. Let's talk with Maurice to see what he thinks. I'm writing a tracking article for the magazine now, and Maurice suggested we could do a series. The tire test could be the next in the series.

We could also possibly combine the tire test with a future Viper Tracks event, its a shame that Viper Tracks 2015 is coming up so soon.

Todd

Nice write up Todd!! How I wish they made the Nitto NT01's in a Viper size.......great wear, decent grip and very predictable.

I don't mean disrespect to the driver of the Z06, but I find it very hard to believe there would be a 7 second difference between the ZR1 MPSC's and R6's if they are both fresh, same temps, same track conditions, similar car set up, etc. It just does not add up.

I know Flatout had the Toyo R888's on his car for COTA, it would be interesting to see what kind of lap times the R888's would produce versus the cup tires or the R6's.

Since the VOA seems pretty damn successful, I'd think they can sponsor the following test:

1. Get some track time at Thunderhill (like an afternoon)

2. Acquire a set of all the top name tires mounted on a set of wheels (Toyo, Hoosiers, Corsa's, Sport Cups, etc)

3. Have 4 or 5 Viper owners who track a lot donate their time to run laps with each of the different tires and record lap times, tire wear and drivers opinions. Swap tires back and forth and use the tracks transponder timing system to record the data. Vehicle on board data systems (like Aim solo) can also be used to add more results such as corner speed, G-force, etc.

4. Document the test Vipers alignment settings before the start of the test.

This would make a great article for Viper Quarterly plus it could be video'd and put on youtube for the world to see (mainly make the PCA and Corvette clubs envious, lol).

There are a lot of us that would be willing to help during the event (not just driving chores) to make this successful.

Cheers,
George

[JonB ~ PartsRack]

Nice comparo Todd,

How about a set of Michelin ACR-X Slicks? [The spec tire for the Viper Cup series?] Did you every try those? Maybe at Parumph when Michael VQ was around with you?

[V10LEE]

Nice thread Todd. It was cool info about the ZR1 cup tires being different to the Cups that came on the Gen 4 ACR. I would like to see a pro driver re run Laguna Seca with the ZR1 setup..

[mjorgensen]

At COTA I ran on both the R6 and the R7 tires. I have run the A6 and R6 for years and I really liked the predictability the R7 had over the older tire. The turn in was softer, but the grip and ability to put power down seemed better. I would also second the need for 18's all around for the track I like a little taller sidewall in the rear (and the front with a 315) for the way I drive. In the day we had at COTA I thought the wear pattern emerging on the R7 was slightly better also, but 2 different cars so that could have been the reason.

[VENOM V]

Nice comparo Todd,

How about a set of Michelin ACR-X Slicks? [The spec tire for the Viper Cup series?] Did you every try those? Maybe at Parumph when Michael VQ was around with you?

Hey Jon,

I ran Continental GT-O slicks, they were ok for the discounted price but nowhere near as good as Hoosiers at least in the narrow 285 and 325 widths I was able to get.

Erich mentions the Michelin slicks every time we've talked tires, he says they're better than Hoosiers. My friend Loyd ran them at Thunderhill on his ACR. Pricey though! Around $2500 per set, right?

[VENOM V]

At COTA I ran on both the R6 and the R7 tires. I have run the A6 and R6 for years and I really liked the predictability the R7 had over the older tire. The turn in was softer, but the grip and ability to put power down seemed better. I would also second the need for 18's all around for the track I like a little taller sidewall in the rear (and the front with a 315) for the way I drive. In the day we had at COTA I thought the wear pattern emerging on the R7 was slightly better also, but 2 different cars so that could have been the reason.

Good to hear Mark. A friend of mine raced with A7s, said they were unreal. I think he ran them at Sonoma Raceway, they work well at some of the tracks around here. Looking forward to trying both flavors.

[VENOM V]

Nice thread Todd. It was cool info about the ZR1 cup tires being different to the Cups that came on the Gen 4 ACR. I would like to see a pro driver re run Laguna Seca with the ZR1 setup..

We just got word that Tommy Kendall and Erich Heuschele will be joining us in a 2014 TA and a Hellcat at Viper Tracks:

http://www.vipertracks.com

I'm hoping we can figure out some sort of tire test, but the auto press will also be there tracking.

It's a shame you'll be out of town Lee, we could continue sparring on track for the lead. Already 70 Vipers signed up. Registration closes Dec 31.

Todd

[FLATOUT]

I have been very happy with the R888's on my TA. Stickier than my Corsa's but not quite as good as the cups I had on my ACR. Straight line the Toyos are fantastic. Only drawback to the Toyo is wet weather performance.

[Nine Ball]

I have been very happy with the R888's on my TA. Stickier than my Corsa's but not quite as good as the cups I had on my ACR. Straight line the Toyos are fantastic. Only drawback to the Toyo is wet weather performance.

After COTA on the Sport Cups, I have better feelings about the PZero Corsas. The Corsas didn't turn slimy after 4 laps, and start to understeer. The Cups were only good after 1 warm-up lap, and then lasted about 2 more full laps before they turned slippery up front. Corsas seemed more consistent, lap after lap.

[V10LEE]

We just got word that Tommy Kendall and Erich Heuschele will be joining us in a 2014 TA and a Hellcat at Viper Tracks:

http://www.vipertracks.com

I'm hoping we can figure out some sort of tire test, but the auto press will also be there tracking.

It's a shame you'll be out of town Lee, we could continue sparring on track for the lead. Already 70 Vipers signed up. Registration closes Dec 31.

Todd

Sounds like a killer event,and we are blessed with the awesome tracks here too. Man I wish I could go..
Yes we had some epic battles at the track together bro! Looking forward to some more this new year..

[XSnake]

After COTA on the Sport Cups, I have better feelings about the PZero Corsas. The Corsas didn't turn slimy after 4 laps, and start to understeer. The Cups were only good after 1 warm-up lap, and then lasted about 2 more full laps before they turned slippery up front. Corsas seemed more consistent, lap after lap.

What hot pressure were you running the cups at?

[rw99]

After COTA on the Sport Cups, I have better feelings about the PZero Corsas. The Corsas didn't turn slimy after 4 laps, and start to understeer. The Cups were only good after 1 warm-up lap, and then lasted about 2 more full laps before they turned slippery up front. Corsas seemed more consistent, lap after lap.

That's good to read. Corsas are next for me, once the Cups are done.

[V10LEE]

What hot pressure were you running the cups at?

This..

30, 31 hot is where I like my Cups. Cold I run the front 25psi and 27psi for the rears..

[FLATOUT]

I was running my Toyos at 31 psi hot per my dash. Didn't notice much under steer at all and the car was quite balanced so I left them equal all the way around. Started the day at 34 hot and worked my way down.

[TrackAire]

That's good to read. Corsas are next for me, once the Cups are done.

The winning combo might be Corsas that are shaven.....probably worth a try.

[Nine Ball]

What hot pressure were you running the cups at?

My target was 31-32 hot, after reading about them from the ACR guys here. They sure go up in pressure a LOT! I had swings of 6-7 degrees cold vs hot. I checked them immediately after each session, to set them when hot. My best laps were at 32 psi hot.