blackey

Ok,

So I'm looking at race wheels for next year. The rules are such. Anthing with a treadwear of 50 or under bumps me up a class. So slicks are the same as Hooisers. Treadwear of 51 to 119 - No class change. 120 and above down a class. The "standard" for treadwear 51-119 is the Toyo RA1. I have no desire to run something with a 120 treadwear.

I've got a set of DPE wheels (18x9 with 7.375" front backspace and 18x10 with 8.5" rear backspace) coming for the rest of this year. I've been waiting for 12 weeks now, for a wheel they said would take two to get... Hopefully they will have them done soon. With these leadtimes, I'm thinking of getting rid of them at the end of the year to get something I can get sooner if I need a new one. I've been dealing with Kodiak for years, and the've treated me very well. They can make pretty much anything.

I've been test fitting wheels just to see what might be.

It looks to me anything from a 16x10 to an 18x10 would fit with a backspace of about 7.875" up front and 8.5" in the back. I know someone said a 16" that wide would not fit, but I test fitted my 16x10 from my Ultima on the front of the S2000, and I do not see any fit issues. It had the wrong backspace, but I did not see issues???? It looks like it would rub the swaybar under full lock, but if your at full lock on race wheels you've got other issues. I don't mind rolling the fenders and fender liners can be modified. I would rather not change fenders, although this is not illegal.

I'm thinking of running the same size tires front and rear...

So these are the options I've come up with:


16x10 with 22x10x16 Hoosier bias ply slicks - same as I run on the Ultima front. This would bump me up a class and I would run against Porsche GT3's on RA1's.

17x9 or 17x10 with 275x40x17 RA1's 9" = 7.375 backspace or 17x10 with 7.875 backspace

18x9 or 18x10 with 275x40x18 RA1's 9" = 7.375 backspace or 17x10=7.875

18x10 with 250x640x18 Dunlop slicks ($$$ might be an issue here)

Thoughts?

rlaifatt

Just some thoughts:

- 275 40 17's are a lot cheaper than 275 35 18's, if cost is a consideration
- With wide 16's you should check clearance of the upper A-arms on droop (based on Raymund's experience with the stock AP1 rear rims on the front)
- 275's are tall tires, so more likely to rub top of fenders, so maybe consider 255 40 front with 275 rear (I run 255's all around to meet Honda Cup regs. for my weight). I think that would be a good balance.
- 18" Dunlop slicks would be the cheapest tires by far if you go with take-offs (tires previously used for qualifying I think). Ry and Davepk would know source.
- Maxrev has given good report on the Nitto's, but I haven't tried them and I don't know how they would hold up over 30 min race compared to RA1's

Whatever you try, let us knpow how they work!

FF2Skip

Richard, could you elaborate or direct me in regards to using rear AP1 wheels on the front? Thanks.

rlaifatt

I can't find Raymund's post but I recall he mentioned the arm touching the rim on full droop (when wheel is off the ground) but I don't recall it was an issue on the track. Maybe Raymund will chime in. On a much wider rim, however, the range of motion could be restricted to the point where it might be an issue on the track (e.g., when you unweight over a hump or rise in the track).

blackey

I'll check. I do have the GFL a-arms though, and they trimmed everything to work with the stock 16" wheels so YRMV. I had one side jacked up with no issues, but the swaybar was connected so it wasn't full droop. Was it front or rear?

In order to put the rears on the front you would need to have the center bore machined out. The rears are something like 62mm and the fronts are 70mm.

So if you weren

Raymund

Hi!

I've been running the 'cheatin' bastard' AP1 rears on all four. Here's thing - in order to duplicate this rub to the upper a arm you would need to adhere to the following guidelines.


1ial in at least 2deg of negative camber with 5.9deg of caster.

2:Get both front wheels off the ground or one wheel only if no swaybar is used to get full droop effect. (note: you will need factory dampers. Droops vary depending on shocks so you need to be able to duplicate factory droopness)

3:Turn to full lock the steering wheel and you should see the inner lip of the 7.5" wheel touch the upper a-arm.


fwiw, I've never actually experience the rub in real world driving or track conditons. results may vary. Have fun!

Raymund

Yes, it will be an issue if the wider rim is 16"in diameter. The bigger the diameter the less issue of rub and the wider you can go. Kind of like those SPC camber kits that won't work with the rear when used with 16" wheels.

rlaifatt

[QUOTE=blackey,May 21 2006, 01:07 PM] So if you weren

pantyraider

I tried the 255/275 combo but that was in Laguna under rainy conditions. I still got massive understeer but I think thats due to my shock compressions settings being off. I'm going to give it another try next track day with softer compression up front. Note that I did get very slight rubbing on all corners.

blackey

My front shocks don't have near the droop of the stock shocks. I suspect that's why I didn't see the issue. I will check it more throughly if I decide to try it.

So what about 275's all the way around?