Wider tires not available...help

I'm making big power in my mr2 spyder with the new engine build and thusly will be needing a bit more bite. The series I'm running pits me against Serious Serious cars. The cars that beat me this year are a new viper acr and a new (modded) gt3rs. The new setup should be in the mid 300s at the wheels and we're shooting for sub 1900 lb weight without driver but we'll see if that's doable. The track we run on is night and rewards small cars so I believe we can be competitive. Treadwear needs to stay 200+, we're running 225/45/15 rival s this year. I hate the idea of big wheels on the car but 225 seems to be about it on a 15. Please help!

Mickey Thompson S/R, I know people have used them on the track and they are 300mm in a 15. Or at least they used to be.

I want to see photos of it, I have a ACR and on even a moderate track with some speed I cannot imagine a MR2 coming close. You are at 5.5-6.3lb/hp and the vipers are just under 5 unmodified. Hell I am 3.9lb/hp with 1200lb's of down-force at 95-100 and its not like a have a fully modified car.

what class is this.

Maxxis came out with their new 200TW this year and they have a 245-40-15

these

It's a tight track, not very well suited to the viper. I have no prayer on a larger track, but a modded elise sc matched the viper's time this year on this track before dnf-ing so I think it's possible. It's a open class, the only rules are treadwear over/under 200 and "clearly a racecar" (seems to mean not road legal, etc.). It's a pretty wild series, really a great group of people, wide variety of cars for sure. Mini roadcoarse is a big equalizer but to be competitive you need some serious hardware these days. It's good though, it's making me raise my game.

Interesting about the maxxis tires, I wonder if they're up to the task.

NEALSMO wrote: Maxxis came out with their new 200TW this year and they have a 245-40-15 these

AWESOME! Those would be almost perfect for Sport Quattro replicas. SQs came from the factory with 245/35R15s.

Yes, 245/35. On a 15 in wheel. Toilet paper rolls with a 5 lug bolt pattern.

sesto elemento wrote: Treadwear needs to stay 200+

What's the reason for that?

Hoosier makes a 275-35-15 A7/R7

red_stapler wrote:

sesto elemento wrote: Treadwear needs to stay 200+

What's the reason for that? Hoosier makes a 275-35-15 A7/R7

A) I daily the car in it's track configuration (I wish the rule was 400 tw, it'd save me money And they dont make acr sized tires that hard )

B) slicks lump me in with formula cars

The 245 maxis will be slower than your 225 rivals. You're screwed unless you go to a 17 inch wheel where you'll have a plethora of tire choices.

And if putting power to the ground is the priority, stick with the rivals.

sesto elemento wrote: A) I daily the car in it's track configuration (I wish the rule was 400 tw, it'd save me money And they dont make acr sized tires that hard )

So daily it with your skinny wheels and swap the beefy hoosiers on at the track?

sesto elemento wrote: B) slicks lump me in with formula cars

So there's no distinction between an actual racing slick and an r-compound radial? What hellscape is this you're competing in?

In reply to Spoolpigeon:

This is the answer I expected, all my research is pointing in this direction. I dont like the idea of:

A) Shelling out the dough for wheelwhore forged 17s (I am who I am)

B) adding unsprung weight to the car

red_stapler wrote: So daily it with your skinny wheels and swap the beefy hoosiers on at the track?

He's said several times that just about the only rule is over 200 tread wear or he's in with open wheel race cars.

wearymicrobe wrote: Mickey Thompson S/R, I know people have used them on the track and they are 300mm in a 15. Or at least they used to be.

Just looked at the MT site. I don't see a TW rating and all the wider tires are much taller overall diameter than he has.

To the OP, what is your upper limit of diameter before you get into gearing issues?

OK, not useless, but a 300HP MR-S that eats Vipers? Come one, we need to see that!

His MR-S

Spoolpigeon wrote: The 245 maxis will be slower than your 225 rivals. You're screwed unless you go to a 17 inch wheel where you'll have a plethora of tire choices. And if putting power to the ground is the priority, stick with the rivals.

I run a Mustang on 17's and if I stick with competing with that car I am looking at moving to 18's due to lack of wider choices.

(max you will find in good 200tw tires for 17" is 255's, if you go to 18's you can get 315 or possibly 335's, then again I doubt you could get heat in them, so 255 may be the better choice)

You may find that getting heat in much about the 225 is going to be difficult. Is this autocross or roadcourse or ???

Apexcarver wrote:

Spoolpigeon wrote: The 245 maxis will be slower than your 225 rivals. You're screwed unless you go to a 17 inch wheel where you'll have a plethora of tire choices. And if putting power to the ground is the priority, stick with the rivals.

I run a Mustang on 17's and if I stick with competing with that car I am looking at moving to 18's due to lack of wider choices. (max you will find in good 200tw tires for 17" is 255's, if you go to 18's you can get 315 or possibly 335's, then again I doubt you could get heat in them, so 255 may be the better choice) You may find that getting heat in much about the 225 is going to be difficult. Is this autocross or roadcourse or ???

Yeah but those are going to be 255/40/17.......much tallers than a 225/45/15.

It looks like a tight road course based on the prior descriptions

singleslammer wrote: It looks like a tight road course based on the prior descriptions

Real tight road course. Like an autox but with banked corners, rumble strips, and about a story of elevation change. Fun little track, good for mr2s, elises, miatas and such. Fastest straight away is probably 65- 75mph or so in a real fast car.

That looks like a riot. Is it a private course?

I wanna go there! Or have someone build a similar track near me, seriously an itty bitty road course seems like so much fun we should have them all over the country.

We had an ACR come out to a local autocross this year and while he did FTD the day, he only beat a CRX by .003 of a second. It really is too bad you can't run Hoosiers. 275s in R compound is worth seconds.

singleslammer wrote: That looks like a riot. Is it a private course?

That looks to be the autocross / kart circuit at Lime Rock.

We tested the 245/40R15 Maxxis a little while back, and that article is now online.

red_stapler wrote:

singleslammer wrote: That looks like a riot. Is it a private course?

That looks to be the autocross / kart circuit at Lime Rock.

That also looks like the Wintercross course, without the snow!

sesto elemento wrote:

singleslammer wrote: It looks like a tight road course based on the prior descriptions

Real tight road course. Like an autox but with banked corners, rumble strips, and about a story of elevation change.

Ooooooh.

red_stapler wrote:

singleslammer wrote: That looks like a riot. Is it a private course?

That looks to be the autocross / kart circuit at Lime Rock.

That it does!