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-   -   Kumho V720 ACR viper tire.. (https://www.camaro6.com/forums/showthread.php?t=569216)

EDFHOBBIES 01-30-2020 08:47 AM

Kumho V720 ACR viper tire..
 
Any tried running the 295 25 19 ACR Viper front tire on the front
and the 305 30 19 non viper tire but could have shaved and heat cycled just like the 355 30 19s that come on the rear of the viper

179.00 fronts
241.00 rears

179.00 sq setup?

apexit53 01-30-2020 10:09 AM

Quote:

Originally Posted by EDFHOBBIES (Post 10712205)
Any tried running the 295 25 19 ACR Viper front tire on the front
and the 305 30 19 non viper tire but could have shaved and heat cycled just like the 355 30 19s that come on the rear of the viper

179.00 fronts
241.00 rears

179.00 sq setup?

I have talked with my guy at the tire rack

He flat out said do 295 square. Said its Magic!

That being said I dont have the money to be testing all the new tires this year.

I would love to test this Vs what to me is the benchmark for me, the RE71R.

Also with the new falken out soon in a 315/30(eta is summer on those)

Vtor_ZL1 01-30-2020 10:34 AM

295 25 19 - now showing $238 each


https://www.tirerack.com/tires/tires...=925YR9V720ACR

Provoste 01-30-2020 10:43 AM

I know Colby Shield runs the ACR tires 295 square on his SS 1LE in Gridlife Time Attack, they're faster than an RE71R.

EDFHOBBIES 01-30-2020 10:51 AM

ebay free ship to 179

Mountain 01-30-2020 11:35 AM

The Viper version of the V720 is a different compound than the regular V720. The regular V720 really is only made to sustain up to autox demands, not track demands. Kuhmo has even said this before and I can attest that the regular V720 do not hold up on track (on lighter cars than the Camaro).

Quote:

The Ecsta V720 is Kumho's Extreme Performance Summer tire developed for passionate driving enthusiasts looking for a tire that was bred for performance and domesticated for civil society. Because its design focus is street use and specifically to excel in the short runs seen during autocross competition, the Ecsta V720 should not be driven on a race track. In addition to delivering Kumho's ultimate performance on dry pavement, the Ecsta V720 provides cool confidence on wet. Like all summer tires, it's not intended to be serviced, stored nor driven in near- or below-freezing temperatures, through snow or on ice.
Outside of that, I thought for most 200tw competitions the Viper version is on an exclusion list?

apexit53 01-30-2020 11:58 AM

Quote:

Originally Posted by Mountain (Post 10712362)
The Viper version of the V720 is a different compound than the regular V720. The regular V720 really is only made to sustain up to autox demands, not track demands. Kuhmo has even said this before and I can attest that the regular V720 do not hold up on track (on lighter cars than the Camaro).



Outside of that, I thought for most 200tw competitions the Viper version is on an exclusion list?

i always here about this list but have never seen it! lol

TheRealJA105 01-30-2020 12:13 PM

Yes the ACR tires are illegal in almost every 200TW class

apexit53 01-30-2020 12:31 PM

Quote:

Originally Posted by TheRealJA105 (Post 10712384)
Yes the ACR tires are illegal in almost every 200TW class

autocross wise yes.

TheRealJA105 01-30-2020 12:44 PM

Right from the SCCA Time Trials Rule book

E. The tire must not appear on the following exclusion list, which may be altered at any time by the Time Trials Board (TTB) upon notification of membership.

- Kumho V720 ACR (less than minimum molded tread depth)

foshjowler 01-30-2020 01:40 PM

Quote:

Originally Posted by TheRealJA105 (Post 10712408)
Right from the SCCA Time Trials Rule book

E. The tire must not appear on the following exclusion list, which may be altered at any time by the Time Trials Board (TTB) upon notification of membership.

- Kumho V720 ACR (less than minimum molded tread depth)

I was about to say, I thought the Kumhos were illegal for autox because of tread depth. I've certainly never seen anyone using them

Mountain 01-30-2020 03:43 PM

They aren't specifically listed in the SCCA Time Trials list, but the way their tire rules are written make them illegal:

Quote:

Tires must meet the following requirements to be eligible for use in Sport Category. No tire model will be eligible for Time Trials competition until it meets all requirements of this section. Tire models not meeting the requirements by April 30 are not eligible for Time Trials competition until after the Time Trials National Championships of the year.

1. Specification

A. Minimum UTQG Treadwear Grade of 200.

B. Minimum molded tread depth of 7/32 inch as specified by the manufacturer.

C. Listed in a current year or prior two years of the “Tire Guide®” and/or the “Tread Design Guide®” (www.tireguides.com).

D. US Department of Transportation (DOT) approval.

E. Tires must be designed for highway use on passenger cars.


2. Eligibility Requirements:
The following are prerequisites before a tire can be used in competition at Time Trials Events.

A. Tire availability: Tires are considered available when competitors can take possession through retail channels. Pre-orders are not considered available.

B. Tires must be equally available to all competitors. Tires that are in short supply do not specifically violate this section. Extensive shortages may result in the tire being placed on the exclusion list until supply is replenished. Tire variations differing from standard specification, delivered only on a limited basis, or only to selected competitors may not be used.

C. Tire models must have tires available in at least four (4) rim diameters and in at least six (6) sizes which meet these requirements.

D. Material Change: Tires which previously met the eligibility requirements that undergo a significant compound change, tread pattern change, or other significant redesign reset the requirement for eligibility described in this section.

E. A tire model which was previously allowed by these rules continues to be eligible for competition until specifically disallowed.

F. Reintroduction: Models that were once discontinued will be considered a new model once reintroduced and must meet all the requirements of this section.
The Viper versions are 6/32, they are "variations differing from standard specification", and are only offered in two sizes.

Now, why Kumho decided to use a different (much, much, much crappier), autox-specific compound on their regular version is beeeeeyond me, as if their normal was anything close to what the Viper version was, they'd be selling a lot more.

ICTsccaCamaro 01-31-2020 09:00 AM

I am running 305 RE-71's in the front and the 355 Viper Kumho's in the rear, it is the best grip i have had so far and I have ran a lot of different sizes in my short 1800 miles of ownership.
305/30R19 front
325/30R19 rear

285/35R19 front
285/35R19 rear

305/30R19 front
305/30R19 rear

325/30R19 front
325/30R19 rear

305/30R19 front
355/30R19 rear

EDFHOBBIES 01-31-2020 09:10 AM

What rim do you run the 355s on? And the dimensions and offset? Any spacers?


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