CSP 2006 MX-5 wheel/tire combos???

[TinmanMS6]

I'm co-driving SPrzyborski's '06 MX-5 next year in CSP, and we're determined to have it MUCH better prepped this year than last (he ran on 215/50-16 RT-615s), but we're having trouble finding a wheel/tire combo that is going to favor this car.

Ron Bauer, who took 2nd at nats in an MX-5, runs on 285/30-18 Kumhos and 18x9.5" wheels. The problem I see with this setup is that it limits us to very heavy and/or expensive wheels and makes the tire taller than what we're starting with, messing up the gearing.

Hoosier makes a 275/35-15 that would probably be great, but the brakes require a 16" wheel to clear.

Can anyone suggest a better tire, or are we pretty much stuck with the 18s?

 

[moxnix]

5 speed or 6 speed?

Ron recommended 16x8 50mm RX-7 wheels with 225/50/16 V710's as a good local budget setup.
http://forum.miata.net/vb/showpost.php?p=2407713&postcount=30

 

[TinmanMS6]

It's a 5-speed.

I think Steve was looking at a similar setup, but I was hoping to find something with a bit more grip than that. It's mostly a local setup for now, but we were hoping to take the car to nationals either this year or next, just for the experience/atmosphere. Neither one of us are near national level drivers, but why not?

I don't know how much tire KCBHIW runs off the top of my head, but we're going to need enough tire to beat him to win CSP locally, so...

 

[aMaff]

IIRC they're 225/13 V710s. His car's also a few hundred pounds lighter than y'alls (based on the Club Racer or whatever it's called model). If you have the higher trim levels, then probably more.


You could probably fit the 265/45/16 V710s on the FD rims.

 

[TinmanMS6]

IIRC they're 225/13 V710s. His car's also a few hundred pounds lighter than y'alls (based on the Club Racer or whatever it's called model). If you have the higher trim levels, then probably more.


You could probably fit the 265/45/16 V710s on the FD rims.

His is a Touring, so it's probably more. I'm not sure how open Steve is to stripping out the A/C, stereo, etc., but he is probably going to be getting a DD sometime in the near-ish future, so this will mostly be a dedicated AX car. Still, I don't think he's too willing to gut the thing.

I think that'd be a very tall tire for this car. According to Miata.net's calculator, that'd add 1.3" to the diameter of the tire.

Why can't somebody make a nice 285/35-16?

 

[aMaff]

Miata.net's tire calculator doesn't take into considerations the 'fudge' room that high performance and R-Comp tire manufacturers tend to build in to their tire sizing. Check the actual specs on tire rack for the overall diameter of the R to the stock. You may be surprised. Then again, I may be surprised. You never know until you work with facts, not guesstimates. I have a feeling it may come out to be about the same as stock.

 

[TinmanMS6]

True, and Miata.net still puts that setup about a half inch shorter than Ron's setup with 18's, and it'd probably save us 3-4 lbs per corner.

Edit: Actual numbers-
V710s:
285/30-18 24.8"
265/45-16 25.2"
225/50-16 24.8"

Hoosiers:
275/45-16 25.3"
275/40-17 25.2"
275/35-18 25.2"
285/30-18 24.6"

...and the stock Yokos come in at 24.1"

 

[Rogue]

i have set of 16x7s for sale. They'll fit the 225s easy.

 

[apexlater]

Kevin is running the 215-50-13 V710. Kumho doesn't make a 225-x-13 tire in the V710.

What else are you doing to the car prep-wise? Suspension? Power adders? If you are'nt anywhere near prepped, then just get whatever tires you can afford, then find wheels that can fit those tires for cheap (and clear the brakes). Then learn what the car does and figure out what you want to improve.

 

[Jas00x]

It looks like if you get a set of 16x9's or 16x10's you could run the cheaper Kumho 225's for now, but then step up to the 265 Kumhos or 275 Hoosiers down the road. I know these aren't the most common miata wheel sizes, but you might find some decent, affordable wheels if you look at Jeep/Truck wheels. I know a few guys have found some really cheap 15x10's that would fit a Mazdaspeed Protege, but were designed for Jeeps.

 

[Jas00x]

Here's the link for some good all-round racing wheels. One of our local BSP Mazdaspeed Miata guys got a set of these. Good price, decent weight, custom sizes. Can't ask for too much more.
http://www.realwheel.net/index.php
More expensive than a Diamond steel racing wheel, but the Real racing wheels are aluminum so they are much lighter.
A quick look online looks like a 16x10 will run you about $250/ea. But I would give them a call to let them know what you want, and what info they need to get everything right.

 

[aMaff]

side note: the eibach pro kits have to go. I think even w/ the azenis, those are still the limiting factor on that car currently. Where's perzyborsky anyway?

 

[TinmanMS6]

It looks like if you get a set of 16x9's or 16x10's you could run the cheaper Kumho 225's for now, but then step up to the 265 Kumhos or 275 Hoosiers down the road. I know these aren't the most common miata wheel sizes, but you might find some decent, affordable wheels if you look at Jeep/Truck wheels. I know a few guys have found some really cheap 15x10's that would fit a Mazdaspeed Protege, but were designed for Jeeps.

GoodWinRacing has 16x9 RPF-1's for $240/ea. that I had my eye on.

 

[TinmanMS6]

Kevin is running the 215-50-13 V710. Kumho doesn't make a 225-x-13 tire in the V710.

What else are you doing to the car prep-wise? Suspension? Power adders? If you are'nt anywhere near prepped, then just get whatever tires you can afford, then find wheels that can fit those tires for cheap (and clear the brakes). Then learn what the car does and figure out what you want to improve.

He's got Konis and Eibach springs on it now, but we're either going to try to find some good coilovers or just pick up some GC's.

I don't think "afford" is necessarily a consideration. We're buying CSP, if at all possible. I think the plan is to have a good car, and hope the driving catches up.

He's already got intake, header, and exhaust. Not sure what else he's got as far as power. I don't know of any options for the ECU at this point, but I'd like to find something. He was talking about getting a lightweight flywheel as well.

Here's the link for some good all-round racing wheels. One of our local BSP Mazdaspeed Miata guys got a set of these. Good price, decent weight, custom sizes. Can't ask for too much more.
http://www.realwheel.net/index.php
More expensive than a Diamond steel racing wheel, but the Real racing wheels are aluminum so they are much lighter.
A quick look online looks like a 16x10 will run you about $250/ea. But I would give them a call to let them know what you want, and what info they need to get everything right.

Wheels aren't really the problem. I'm just having trouble finding a good tire for the car. Once we pick a tire, we'll find wheels to mount them on.

side note: the eibach pro kits have to go. I think even w/ the azenis, those are still the limiting factor on that car currently. Where's perzyborsky anyway?

Again, new suspension is in the works. Also, he's talking about picking up the Mazdaspeed LSD. He has to put on the Eibach FSB still, and throw away the Eibach RSB, and the stock one as well.

 

[aMaff]

I'm sure y'all are using the Ron Bauer car as more or less of a template. What kind of spring rates are they running? Because the Koni sports can only handle so much without being in dire need of a revalve. Does the MX5 suffer from shock travel issues like the NA miatas (ad to some extent also the NBs, but not as bad)? A revalve and shortening if necessary may be something to think about if he can handle the car being on jackstands for a while.

 

[steverife]

How about a 245/45/16? In addition to the Hoosiers, Kumho is supposed to release a V710 in that size for next season. That's what I plan to run on the front of my 3.

 

[TinmanMS6]

I'm sure y'all are using the Ron Bauer car as more or less of a template. What kind of spring rates are they running? Because the Koni sports can only handle so much without being in dire need of a revalve. Does the MX5 suffer from shock travel issues like the NA miatas (ad to some extent also the NBs, but not as bad)? A revalve and shortening if necessary may be something to think about if he can handle the car being on jackstands for a while.

The Bauer car is currently sporting JIC Magic coilovers, but on the website he says they're looking into better springs for next year.

 

[Jas00x]

I'd stick to the Koni/GC setup personally, and recommend the revalving and shortening as necessary.
As for wheels, you should really try to go 9.5" or bigger. 9" will be fine for the 265 or 275 (I run my rear 275's on 8.5" rims), but you can figure that as you go up in rim size, you are gaining almost that much that in contact patch when you go from a tight fit to a nice fit. Also, it makes it easier on your tire guy.
I'm not sure if you know Dan Pedroza, but he has built a bunch of Miatas (including a CSP MX-5), so he may have some setup notes to share. I think he can be found on SCCA forums, if not, I can get you his email.

 

[aMaff]

Speaking of koni/GC, I'm actually moving away from that setup slightly. I went through Tri-Point motorsports and got a set of Koni Racing threaded sleeves that allow you to run lighter weight 2.25" springs along with some hypercoil 2x2.25" springs. With the GCs, you have to run 2.5" springs. It was something like $50 for the sleeves, and you can also get an adapter to run 2.5" springs if you need them. They should be here tomorrow, so I'll post pics when I can. If you're interested, talk to Jeff@Tri-Point (a vendor on this forum). In the end, this comes out to be about $150 cheaper than the GC setup for my car.