15 inch wheels for 90 CRX

[REPPHD]

thanks guys.

I run 225 50 R 14 at 22.8 OD, 9 inch width KUMHO which are a bit wider than Hoosier

225 50 R15 would be 23.7 OD sames width.

At RA I run the 4.73 gears. Now I know I could go back to 4.11 which would change the rev pattern and that is an option for next year.

I ran 2.50 on Saturday, did not try and go fast on Sunday as it was my last race this season anyway and I was not running enough to challenge anyone in points. I think i could have run about 2:49 or a bit better with what I have. I run 650's in the back springs and my motor is good, but has no piggyback just a 6 year old chip at this point. In going through the carousel and Kink I would like to up my speed there and I have been pretty conservative there so I know I have time to make. My thinking with more OD, I would have less revs so be in a better power band to go into Canada and also pick up some advantages. Right now I do about 7000 into 1, 7000 into 5, but best into 12 was about 6700 on Saturday and maybe 6300 on Sunday.

So I think what you are telling me is it possible; we fixed the rub on the Kumho 14's early on; The 15 inch wheels I think are good at about 11 lbs are 35mm offset (miata). Bigger tires weigh more, but wheels keep total unspring weight gain to a minimum.

If I want to run with Midwest Council in the top three I have to be 2:48 and we did see 2:47 and even faster this year with a couple of national miata guys.

Further thoughts?

[Chip42]

225 50 R15 would be 23.7 OD sames width.

225 45 R15 hoosier is 22.9" diam.

At RA I run the 4.73 gears. Now I know I could go back to 4.11 which would change the rev pattern and that is an option for next year.

taller tire is like going to a smaller gear. doing both would be murder unless you stepped down the gearbox and even then it rarely works out well as the spacing tends to increase in the bottom of the box. what you are talking about is a ~10-15mph change in 4th gear speeds at 7k RPM, and less acceleration on the way there.

So I think what you are telling me is it possible; we fixed the rub on the Kumho 14's early on; The 15 inch wheels I think are good at about 11 lbs are 35mm offset (miata). Bigger tires weigh more, but wheels keep total unspring weight gain to a minimum.

just be careful, Miata wheels are 54mm center bore, honda is 56. also, most of the Miata wheels I've seen are +45mm offset. spacers can take care of both problems though.

[Xian]

As others have said... yeah, 225/45 15 will fit. It's super duper tight in the rear (especially) but it'll work. Unless you've got a stockpile of 15x7's I wouldn't bother with it myself. Run the 225/50 14. Their slightly taller sidewall isn't bad thing in a SWB car like the CRX...

There's no way that I'd move an ITA CRX onto 225/50's. The taller tire height will raise the car, create clearance problems, hurt gearing, etc. No way, no day.

[adamjabaay]

I've been toying with the idea of running spec miata 205's 15'' tires on my crx

don't know if it'll happen. Lazy

[Davegt74]

(Keep in mind I am running solo II since I am trying to sell the Honda)

I switched to 225/45ZR15 Hankook s with RPF1's and I went and bought a fender roller

turns out my car's fenders where already rolled for the larger wheel and tire combo, I do have some slight rubbing in the rear and the front right I am finding grease on the front outer cv boot (I have wiped it off twice and can’t find any holes)

Here are the reasons I would not go with 15's (what I told myself in the past)

1) Doing so raises the ride height of the car (it’s normally anathema to raise the CG height of a car)


2) The tires and wheels are more expensive


3) Changes the final ratio

BUT I knocked off 2 seconds when I did it so that killed my arguments against doing it.

For this Sunday I am going up on the front spring rate 50 pounds to 500lbs

Davegt74

[Xian]

Assuming you're referring to the typical ITA wheel sizes...

1- 225/45 15's are essentially the same height as the more common 225/50 14. No ride height change results... and even if it did, you've got coilovers to adjust ride height.

2- Wheels and tires are cheaper on the used market due to increased commonality with other cars.

3- FD stays the same b/c of #1.

If you're comparing to the 225/50 the OP asked about, all of the common 15" sizes will lower the car and improve the effective FD. If you're comparing to something like a 225/50 13 then yeah... 15's would change things pretty drastically.

[madrabbit15]

We run 15 x7s with 205/50/15 hoosiers and kumhos. Works great, no problems what so ever. I personally don't see how any of the guys running 225s can do it. We have tried numerous ways and we either rub the rear trailing arm or the track is wider than the fender. Personally I think the 205s are faster than the 225s anyway. Takes too much hp for those wider tires on the faster straights.