VitaRenovatio

I am thinking of using 4 AP2 rear wheels but running staggered tire setup 225/255. All things being equal, this should increase traction in the front tires since the wheel will be 1.5" wider. However at the same time, the offset will be increased by 10mm, which, all things being equal, will reduce lateral grip.

What do you guys think about the idea of using 225 on AP2 rear wheels in the front? Will the increase in wheel width overcome the decrease in track?

The other alternative is to run a 5 or 10mm spacer, but then there are more issues: are spacers safe for track duty? And will the rear wheel even fit without fender modification? I plan on using approximately -3 camber all around...

Interested to hear people's inputs...

JstnRyan

I can't think off the top of my head what the stock AP2 setup is, but it sounds to me like you want to run 4 rears, with the same tire stagger. Aside from the offset difference (which, when considering wheel width, is negligible), that kind of defeats the purpose of running a wider wheel in front, doesn't it?

The way it looks in my mind, using the same tire size on a wider wheel may hurt your front traction, more than help, as the tire will be stretched on the wheel. For better front grip you want a wider contact patch, hence the wider wheel.

VitaRenovatio

^ I disagree. A wider wheel wheel will give you more grip on the same tire, so long as it isn't stretched beyond its recommended range of wheel widths. As far as all the tires I care about (RE-01R, RE-11, Z1 Star Spec, R888, NT-01), a 225/45R17 has a recommended wheel width of 7-8.5". FYI, AP2 rear wheel is 17x8.5" +65, and AP2 front wheel is 17x7" +55.

JstnRyan

While you have a point, I think that buying an additional set of rears just to try and get that SLIGHTLY flatter contact patch is quite a bit of work for absolutely minimal gain that I highly doubt you'll be able to feel.

Personally, I prefer to run a tire that has a rim width rating in which my wheel is right in the middle. For example: 8" rim, tire suggested rim width 7.5" - 8.5"

Keep in mind you can control your tire contact patch with air pressure, as well.

VitaRenovatio

How do you know the difference is only slight? Do you have firsthand experience with running the same tire on different wheel widths? FYI, 225/45R17 R888 tire is 9.1" wide. Does sticking a 9.1" wide tire on a 7" rim sound optimal to you?

Also, it's not a lot of work, as I plan on getting an extra set of AP2 wheels anyway. I will just run 4 fronts for daily driving (on cheapo 205/225 tires that will probably get camber worn to hell), and 4 rears for track use (with expensive R-comps or sticky street tires).

JstnRyan

Don't get me wrong; I'm not trying to argue this point with you to the point of telling you not to do it. Try it, and if it translates in reduced lap time, then stick with it.

Clearly you've done your research on this issue concerning the sizes of your tire choice, and I have not. I was speaking in generalizations, as there is no "standard" for measuring the qualities of a tire. I certainly don't claim to be a tire expert.

rob.ok

Nam, 16 inch (AP1) wheels make the S2000 very unstable. Upgrading to 17 inch wheels (regardless) of the size will be a noticeable improvement in the way the car feels and handles.

I'm assuming the real reason is to upgrade to a non-staggered setup later on once you acquire a wing....if that is the case I think your on the right track.

I'm not a big believer in running stretched tires...I think the benefits are negotiable. I prefer to run the recommended rim width for the tire I've chosen. From there....stretching the tires is another means of tuning.


Spacers are safe. Even with a 5mm spacer though...you might want to think about changing the studs to longer ones. Instead of getting he wheels bored to match the hub..I'd just run the spacers.

VitaRenovatio

Thanks for the input, Rob. I am actually running 225/255 RE-01R on AP2 wheels now, and they were a definite improvement over 205/225 S-02 on AP1 wheels (no surprise there).

The 8.5" width of the AP2 rear wheels is within the recommended range of rim widths (7-8.5), so I figure it wouldn't really be stretched, more optimized, especially since R888s are quite a bit wider than your everyday tire. Also, I don't think I can run nonstagger on my car as is--maybe if I got coilovers or CR suspension--but as is, the car is pretty well balanced with my APR GTC-200 wing and I think running nonstagger would result in too much oversteer. FYI, it seems the MY2002-2003 had its suspension tuned for staggered setups: The spring rates are 249 (4.4 kg/mm) front and 306 (5.46 kg/mm) rear. The sway bar thicknesses are 26.5mm front, 27.2mm rear

I don't know... maybe I should give up on the staggered 225/255 R-comp idea and go with CR coilovers on 255/255 RE-01Rs...

Jaku

i would max out the front mechenical grip and dial in the overall balance from alignment, rear downforce, different MY springs or sway bars etc

the front won't rub 255 with +65 oem rear wheels, thus same as 225 up to 15mm spacer, so your fender will be fine with either setup

you can also try without spacers for your 1st time out if you worry too much front grip

i know Kicks makes 10mm stud type spacer, but not sure about the stud clearance on oem wheel, longer studs like rob said is good if you can find a shop with cheap labor

225 on 8.5" wheel is fine, Emilio runs 225 on 9" wheel for his miata, he proved it's faster than 8" wheel

i was also faster on 10" than 9"

VitaRenovatio

Thanks, Jaku! Very informative information... esp. the part about Emilio actually testing the same tire on different width wheels out on the track. I think I will go for 225 R-comp on AP2 rear.

Will AP2 rear with 10mm spacer fit in the fender without modification? Or should I try 5mm first? Or no spacer at all (but would probably mean that the tire would be closer in than on a AP2 front wheel, and I would have clearance issues at full lock).