ACR Guys with 275/35 fronts & 345/30 rear Michelin Super Sports... opintions please.

[msp282]

the fronts are 20mm narrower than stock but i am guessing with my typical street driving i won't notice. I can't drive on Sport Cups on days like today (low 20's in AM and going up to 30's but with some rain)...

just wanted to get some feedback from ACR guys running this combo.....

thanks


09 ACR

 

[msp282]

Re: ACR Guys with 275/35 fronts & 345/30 rear Michelin Super Sports... opintions plea

DOH.... was supposed to warm up and rain....

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[Viper Parts of America]

Re: ACR Guys with 275/35 fronts & 345/30 rear Michelin Super Sports... opintions plea

There is a slightly bigger Super Sport available for the front - 285/35-18:

https://www.viperpartsofamerica.com...t-set-for-2003-2010-viper-285-35-18-345-30-19

Seems many ACR's swap out the Cups unless they are tracking the car. Even then many buy a spare set of wheels/tires and save the semi-slicks for the track. Nitto just started building the Invo in 295/35-18 again and already makes the 345/30-19 for the rears - just another option if you aren't tracking the car.

 

[mjorgensen Woodhouse]

Re: ACR Guys with 275/35 fronts & 345/30 rear Michelin Super Sports... opintions plea

The PS2 is also still availible in the 295/345 in a pinch.

 

[ViperGeorge]

Re: ACR Guys with 275/35 fronts & 345/30 rear Michelin Super Sports... opintions plea

I've run the PSSs in both the 275/345 combo and the 285/345 combo. Honestly I can't tell the difference and I track my ACR.

 

[08viperviolet]

Re: ACR Guys with 275/35 fronts & 345/30 rear Michelin Super Sports... opintions plea

I went from the cups to the PSS and not a big diffrence went with the 275 the 285 is taller tire. Drive my car every day in south florida rain. Think you will like them talked to other Acr owners and they run them on the track also and are happy. Good luck.

 

[msp282]

Re: ACR Guys with 275/35 fronts & 345/30 rear Michelin Super Sports... opintions plea

The cups are a bit scary here in the rust belt..... I think I may just go with the 275's and save the couple hundred dollars....... Thanks guys!

 

[VIPER GTSR 91]

Re: ACR Guys with 275/35 fronts & 345/30 rear Michelin Super Sports... opintions plea

I have run the 275 but prefer my current set up of Super sports 285 front and 345 rear for street anyway. Awesome

 

[SoCal Rebell]

Re: ACR Guys with 275/35 fronts & 345/30 rear Michelin Super Sports... opintions plea

I've run the PSSs in both the 275/345 combo and the 285/345 combo. Honestly I can't tell the difference and I track my ACR.

I bet you the stop watch knows the difference PSC = 80 treadwear rating, PSS = 300 treadwear rating this is a much harder compound.

 

[JAY]

Re: ACR Guys with 275/35 fronts & 345/30 rear Michelin Super Sports... opintions plea

Not to Hi Jack ,But anyone running 305's or 315's ?

 

[ViperGeorge]

Re: ACR Guys with 275/35 fronts & 345/30 rear Michelin Super Sports... opintions plea

I bet you the stop watch knows the difference PSC = 80 treadwear rating, PSS = 300 treadwear rating this is a much harder compound.

No, I'm saying I can't tell the difference between the 275s and the 285s. Not the between the Cups and the PSSs. Of course the Cups are faster.

 

[SoCal Rebell]

Re: ACR Guys with 275/35 fronts & 345/30 rear Michelin Super Sports... opintions plea

I've run 305s, 315s, 325s and 335s on the front on the track. 325s were great when they were available, 335s were a bit much 305s and 315s especially when you are running Hoosier R6s are perfect. Vipers tend to push like a dump truck in the corners so a good alignment and the wider tires on the front are essential.

 

[JAY]

Re: ACR Guys with 275/35 fronts & 345/30 rear Michelin Super Sports... opintions plea

Thanx SoCal Rebel ! You confirmed my thoughts !

 

[Herc]

Re: ACR Guys with 275/35 fronts & 345/30 rear Michelin Super Sports... opintions plea

I've run 305s, 315s, 325s and 335s on the front on the track. 325s were great when they were available, 335s were a bit much 305s and 315s especially when you are running Hoosier R6s are perfect. Vipers tend to push like a dump truck in the corners so a good alignment and the wider tires on the front are essential.

I think I heard the under steer was on purpose to keep most out of trouble on the street. Track is another story.

Herc

 

[ViperGeorge]

Re: ACR Guys with 275/35 fronts & 345/30 rear Michelin Super Sports... opintions plea

I think I heard the under steer was on purpose to keep most out of trouble on the street. Track is another story.

Herc

Under steer is designed in as it is easier for the average driver to deal with. Your initial reaction when the car is under steering is to lift off the gas. This transfers weight to the front tires which gives them more traction and they then can turn more. Exactly what you want with under steer. Over steer is far more difficult for the average driver to deal with. If the car is over steering (rear wheels not turning as much as fronts) if you lift off the gas you simply make the situation worse as the fronts turn even more and the rears (with less weight on them) turn less. Result? The rear end comes around. So bottom line is you are correct.

 

[am.mscl]

Re: ACR Guys with 275/35 fronts & 345/30 rear Michelin Super Sports... opintions plea

A mention of the Nitto Innvos 295/35ZR18 was made here. Looking at the specs on the tire it is 1" total Diameter more then the PSS and PS2 295/30ZR18.
Is that 1" going to make any difference on an ACR with Street friendly alignment for a car that is going to see 99.5% street driving?
Thanks
Ray

 

[Viper Parts of America]

Re: ACR Guys with 275/35 fronts & 345/30 rear Michelin Super Sports... opintions plea

This is one of our favorite tire size comparison sites, although it doesn't go up to the 345's for a Miata - go figure: http://www.miata.net/garage/tirecalc.html

You can see the graphical difference between the different available tire sizes, from the original Gen 4 ACR size 295/30-18 to factory size for all other Gen 4 Vipers (275/35-18). Given that they are the same wheel size on all Gen 4 cars (18x10), fitment isn't an issue and it would seem that they would work just fine for the street, as many owners can attest. Hope this helps!

 

[Viper X]

Re: ACR Guys with 275/35 fronts & 345/30 rear Michelin Super Sports... opintions plea

I run the 275 fronts, 345 rears in PS2 C1 configuration on the street - when I pull the Hoosier off. They work fine under most conditinos, but I don't run the car ******* the street.

On the track the PS2's and the PSS would be push and squeal like crazy the way I drive my car, i.e. aggressively.

As above, many of us with ACRs have multiple sets of tires and wheels. 315's up front (R6 or A6) seem to work best on the track or Auto X, though 295's work OK on tighter tracks.

Dan

 

[TexasTonka]

Re: ACR Guys with 275/35 fronts & 345/30 rear Michelin Super Sports... opintions plea

Not to beat a dead horse here but I have a few questions on going with the PSS. I have them on my 6 spokes (285/345) on my '96 GTS TT and love them, but am acquiring a 2009 ACR in the next few days and since it is 4 years old with 500 miles on it, I am putting new shoes on her before taking her out.

First question would be where does the speedo get its signal? If it is from a tone ring in the rear diff or rear hub then there is no speedo change, if it is front hub then going with anything but a 295/30 (or 25" tall tire set get your speedo off a few MPH).

Now on Size, the 295/30 is 25" tall with 11.6" width. PSS 285/35 is 25.9x11.2, PSS or PS2 275/35 is 25.6x10.8. Invo is over a inch taller so out of the question. So the 285 is almost a full inch taller, this would raise the front of the car. The 275 is 1/2" taller so not so much of a aerodynamic worry but it is almost a full inch narrower. I understand the ACR suspension is adjustable, but once ride height, corner weight, alignment is set you don't want to throw on a tire an inch taller.

90% of my driving is twisty back country roads and freeway blasts with occasional trips of 300 miles or more. But the car was designed to use 295 cups, right?

I like the PSS a hell of a lot, think it is almost a perfect tire. Looking at the numbers it looks like the 295/30 PS2 and the Sport Cup is really the only option, especially if speedo is off front hub tone ring.

Anyone have any contacts at Michelin to know if they will replace the PS2 295/30/18 with a PSS 295/30/18??


Any ideas, thoughts or opinions would be appreciated.

Have a great weekend!