Tire size/choice question! Help!

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Brownsound

Tire size/choice question! Help!

Postby Brownsound » Sun Oct 05, 2008 5:02 pm

I had some great help at the Oct. autocross with tire info, but now I need some real advice!

I have RE01R's all around on my AP1 S2000, 205's up front, 225's in the rear. The rears are completely spent, so I am trying to decide what to replace them with!

Three choices I am thinking of:

A. 225/50/16 Dunlop Z1 Star Spec's

B. 245/45/16 (Oversized) Hankook R-S2's
or
C. 225 RE01R's again (more expensive than I'd like to spend again)

So whats the best choice? Help a newbie please! Thanks! :)
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WAFlowers
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Postby WAFlowers » Sun Oct 05, 2008 5:18 pm

245/45/16 are NOT oversize on our AP1's. The OE tire has a weird profile and, despite what it says on the tire, are approx. the equivilent of 245/45/16 from any other make.

I have Hankook R-S2 245/45/16 on my rears.

That said, they are not as good a tire for AutoX as Falken Azenis (not available in a size for our AP1 wheels) or the Dunlop StarSpec.

Jack Neely has a newish set of StarSpec's on his S2K and had VERY favorable things to say about them.

When I can, I think I'll get a set of AP2 wheels and put StarSpec's on them to get an even bigger contact patch for more grip. It would kick me out of stock in SCCA, but I dont' do SCCA. :twisted:
The Jag complains about autoX by throwing Gearbox Faults.
I think it is just lazy.
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Postby Dave-ROR » Sun Oct 05, 2008 5:35 pm

StarSpec's seems to be a current tire of choice, I'd try them.

As Bill said, 245 is the proper rear tire size, go either 205F/245R or 215F/255R (if proper sizes in 215/255 are avail)
-Dave
I drive really slow cars... really slowly.
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Brownsound

Postby Brownsound » Sun Oct 05, 2008 5:41 pm

Thanks for the reply, I understand that our OEM size is much closer to a 245/45 than what is officially stated. Is the R-S2 the best 245/45 available? I haven't found a better tire in that size. If there is not a better option, I am going to try the Star Specs.
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Brownsound

Postby Brownsound » Sun Oct 05, 2008 5:43 pm

Dave-ROR wrote:StarSpec's seems to be a current tire of choice, I'd try them.

As Bill said, 245 is the proper rear tire size, go either 205F/245R or 215F/255R (if proper sizes in 215/255 are avail)
The only problem is for AP1 wheels, it is very hard to find a 245. The maximum star spec size is 225.
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Anonymous

Postby Anonymous » Sun Oct 05, 2008 6:05 pm

I would go with choice D.

Direzza Sport Z1 Star Spec 225/45ZR17
Direzza Sport Z1 Star Spec 255/40ZR17
Enkei RPF1 17 X 8 +45
Enkei RPF1 17 X 9 +45
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Postby Loren » Sun Oct 05, 2008 6:07 pm

Relative scale of tire goodness, Street Tire version:

Star Spec > RE01R > Azenis > RS2 > Everything Else

I haven't personally tried them, but the new Toyo R1-R might be a contender. Ron Croft seems to think so.
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The "Push Harder, Suck Less" philosophy explained:
Push Harder - Drive as close to the limit of your tires as possible.
Suck Less - Drive something resembling a proper racing line.
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Brownsound

Postby Brownsound » Sun Oct 05, 2008 6:16 pm

Star Specs ordered! Man I gotta get me some AP2 wheels again :/ Thanks for the replies guys
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Brownsound

Postby Brownsound » Sun Oct 05, 2008 6:17 pm

Jeremy wrote:I would go with choice D.

Direzza Sport Z1 Star Spec 225/45ZR17
Direzza Sport Z1 Star Spec 255/40ZR17
Enkei RPF1 17 X 8 +45
Enkei RPF1 17 X 9 +45
I wish :cry:
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Postby Agent » Sun Oct 05, 2008 6:30 pm

If you could get the same width and ratio tire in 16's and 17's, which one would be the better choice? Wouldn't a 225 16 grip better than a 225 17?
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Anonymous

Postby Anonymous » Sun Oct 05, 2008 6:38 pm

Shorter sidewall improves turn in. So the 17" would probably be faster.

As far as which has the most overall grip, not sure. Probably close to the same.
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Postby Loren » Sun Oct 05, 2008 7:00 pm

Agent wrote:If you could get the same width and ratio tire in 16's and 17's, which one would be the better choice? Wouldn't a 225 16 grip better than a 225 17?
Just like when you're talking about suspension... stiffer is not always better. Like at SPC where there are some distinct bumps, sometimes right in the middle of a turn, having a little bit of sidewall to absorb that impact can be a good thing. If we ran all of our events at Brooksville (and especially if Brooksville had nice smooth joints), there would be no downside to using the lowest profile tire with the stiffest possible sidewall.

Also, to inject the real world back into this conversation... low profile tires and potholes often add up to bent wheels.

But, to specifically answer the question THE WAY YOU ASKED IT... there would be NO difference in grip between a car fitted with 225/50-16's and one fitted with 225/50-17's. You specified "same width and ratio". That's not typically how it's done, but that's what you said.
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Suck Less - Drive something resembling a proper racing line.
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Postby WAFlowers » Tue Oct 07, 2008 9:45 am

Loren wrote:Relative scale of tire goodness, Street Tire version:

Star Spec > RE01R > Azenis > RS2 > Everything Else
And I'm at RS2 in the above comparison. Badly worn RS2's at that!

I've gotta get my baby some new shoes. :roll:
The Jag complains about autoX by throwing Gearbox Faults.
I think it is just lazy.
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Postby Loren » Tue Oct 07, 2008 10:35 am

That's okay, Bill. I'm running Toyo T1-R's and getting my ass handed to me!
Loren Williams - Loren @ Invisiblesun.org
The "Push Harder, Suck Less" philosophy explained:
Push Harder - Drive as close to the limit of your tires as possible.
Suck Less - Drive something resembling a proper racing line.
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Postby Blacknot » Wed Oct 08, 2008 3:57 pm

I know some guys are running 245 up front and 275 in the rear on Ap2's. I'm thinking og going 225/255 or maybe 245/255. Others have had great results with these set ups. My 320 treadwear tires suck
Ron
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Postby Jack » Tue Dec 02, 2008 1:37 pm

after lots of trial and error, star spec on ap1 wheels, i am now running 225 all around and it works great.
i just ordered hankook z 214 r comps today!
i am going to run a 225/255 set up on 16 ap1 wheels
not shure if i am going to race tires for fast event though.
i like the comp in g class :lol:
i need them to be competitve in a stock scca!
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