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Old October 27th, 2009, 12:16 PM   #1
WC13
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Track tire advice/suggestions

As the track season wraps up here in the Midwest it is time to start planning for next year....

Up to this point I have just been going out with what I've got, working more on my line and driving than my equipment. I am now at the point that I want to start getting better equipment.

First up for change is my tires. I have some 17" turbo twists that have some Hankooks on them. They were fine for my street use (not great track tires) but they still had some life so I figured I would wear them out on the track and get better tires next year.

I want to keep the cost of tires down since it is all a part of the same budget (more $$ on tires = less $$ for track events). Knowing I was going to be looking for tires for next year I began asking around at events. I had several suggestions for Michelin, Pirelli or Bridgestone, but they tended to be on the higher end of the $$ scale. The ones that got good recommendations and were on the less expensive side were the Falken Azenis & Kumhos Ecsta XS.

The problem..... they do not come in 205/50-17.... Is there a different size tire I could use up front? Someone suggested 225/45-17 as that would not change the speedo reading. But wouldn't putting that much more rubber up front significantly change the handling (more oversteer)? The Azenis come in 205/40-17. What will lowering the sidewall ratio do? Any other suggestions for tires?

I know there are a lot of track & AX guys on this site and was hoping for some suggestions.

Many thanks!!
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Old October 27th, 2009, 12:40 PM   #2
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check out Bridgestone RE11s

as far as sizes you should be running 225x45x17s up front on the 7" wheels
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Old October 27th, 2009, 01:01 PM   #3
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I don't think that 225 up front induces oversteer, but it actually reduces understeer
I like the Dunlop Direzza Star Spec Z1 very much as a street/track hybrid tire (they seem to last much longer than the Nitto NT-05 I had before which didn't stick any better), the only problem I had that I took them to the track brand new and the front right started chunking, but I'd guess that this would happen with any brand new tire with lots of thread (as opposed to shaved). The Dunlops have an initial thread of 10/32 as opposed to the new thread of 6/32 for the Nittos (that would also explain why they don't last that long)

If you want to know how you car feels with 225 in front:
I switched to 18" wheels and still have 2 225/45/17 Bridgestone RE050PP (with about 5~6/32 thread left) which I am selling for $25 / piece + shipping
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Old October 27th, 2009, 02:42 PM   #4
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Two years ago I switched to 225/45-17 since the Falken Azenis RT-615 tires I put on did not come in the 50 series. I like the feel of the car much better and it definitely takes out some of the low speed understeer these cars are built with. The plus side is that you also have move rubber on the road for braking!
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Old October 28th, 2009, 07:47 AM   #5
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Quote:
Originally Posted by Docdanracy View Post

as far as sizes you should be running 225x45x17s up front on the 7" wheels
Did not know that. I always just stayed with the same size that came on the car. On that same note, should I keep the rears at 255x40x17 or should those be adjusted too?

Thanks!
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Old October 28th, 2009, 08:35 AM   #6
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Leave the rears at 255. To move up in rear 17" size, you have to go to a 275 and they are quite tall in comparison with the 255s. Changes your gearing and the idea of the 225 up front is to get a little more tire patch so you can negate some of the factory built in Understeer.
If you go wider front and rear, you have only went up in size but not changed the front rear dynamic.
Also get a good alignment, and try to maximize your front negative camber..with a stock suspension you will only be able to get about -.7 or -.8 maximum....not great but better than from the factory at almost 0.
the more negative front camber, the better your tires will wear (not killing the outside edge) and you will get better turn in.
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Old February 4th, 2010, 11:00 AM   #7
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Quote:
Originally Posted by ChrisZang View Post
I don't think that 225 up front induces oversteer, but it actually reduces understeer

I switched to 18" wheels and still have 2 225/45/17 Bridgestone RE050PP (with about 5~6/32 thread left) which I am selling for $25 / piece + shipping
Chris: Couple questions... 1) What difference do you feel running the 18s compared to the 17s and 2) What size tires are you running on your 18s.

Since I am getting a 2nd set of dedicated track wheels I am trying to decide which size I should go with.

Thanks!
Colin
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Old February 4th, 2010, 11:11 AM   #8
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I had 18s on my 2.5 and sold them after 6 months. They where heavy and I did not feel they worked any better overall than the exact same tires on 17s.
17s are much cheaper for wheels and tires.
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Old February 4th, 2010, 12:30 PM   #9
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I'm trying to decide between these sets of tires: Dunlop Direzza Star Spec Z1 or Kumhos Ecsta XS? I'll use them mainly for AXs.

Any recommendations?
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Old February 4th, 2010, 12:56 PM   #10
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Switching from 205/50/17 to 225/45/17 will be one of your best decisions made to the Boxster Your car will be much more neutral (still a little under-steer) than before (crazily under-steer). Keep the rear the same, 255/40/17 is good.

I love my track tires. My Thunderhill track time was improved by 13 seconds, (yes you heard it right, 13 seconds), simply by swapping street Michelin PS2 to track Toyo R888. One other benefit of R888 is that you can still drive (it's road legal and safe) to the track without towing a trailer with tires.

Have fun~
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