CRX Hoosier fit

[Domino]

I switched to 225 S05's at the last race. I ran 225 710s prior to that with no prob. They are on Team Dynamic 14x7s. I had to put 2 5mm spacers on each rear corner to prevent the S05's from rubbing the trailing arm. This has pushed them a little too far beyond the fender. I suppose the next step is to put 205s in the rear. Has anyone else had similar experiences? How much softer does the rear need to be to compensate?

[Xian]

The 225's will fit on the rear and when "tested" per the GCR pass the talcum powder test. To keep them from rubbing, the inner fender lip will need to be thoroughly rolled... one of the the side effects this may cause is to push the fender out a bit.

I've been running the same 225 tire/wheel combo you have and although it pushes right to the edge of the rules, it passes :D

Christian, who had one of the scrutineers eyeing his rear tires last month at CMP... him: "those are almost too far out"; me: "almost is what I was trying for..."

[RSTPerformance]

one of the the side effects this may cause is to push the fender out a bit.

I've been running the same 225 tire/wheel combo you have and although it pushes right to the edge of the rules, it passes :D

Christian, who had one of the scrutineers eyeing his rear tires last month at CMP... him: "those are almost too far out"; me: "almost is what I was trying for..."
[/b]


I think as a competitor I would argue it does not pass... In my mind you can not "push" your fender out at all to get your tires to fit. If that was the case then I would be running different tires on the rear of my Audi.

If I am worng certainly tell my why/how and I could possibly be convinced to change my opinion.

Raymond "just my opinion" Blethen

[Phat-S]

I switched to 225 S05's at the last race. I ran 225 710s prior to that with no prob. They are on Team Dynamic 14x7s. I had to put 2 5mm spacers on each rear corner to prevent the S05's from rubbing the trailing arm. This has pushed them a little too far beyond the fender. I suppose the next step is to put 205s in the rear. Has anyone else had similar experiences? How much softer does the rear need to be to compensate?
[/b]


I too can't possibly fit a 225 on a 7" rim on the rear of the car. I have the same 14x7 TDs and my 225s on those rims require 2x3mm -- 1/8" -- spacers on the rear to fit - w/ the 205s, they only need one 3mm spacer. I have run both the 225-50 on the 14x6 and 205-55 on the 14x7s. I think its a wash between the two as they are about the same width. As for how much you need to soften up the rear for the 205, I don't think you have to at all ... but then again, I have yet to run Road Atlanta w/ the 225/205 setup and I was told by a Road Atlantian that my car feels a bit more twitchy than he would like there. If you are worried, can you just disconnect the rear sway bar?

[Domino]

I too can't possibly fit a 225 on a 7" rim on the rear of the car. I have the same 14x7 TDs and my 225s on those rims require 2x3mm -- 1/8" -- spacers on the rear to fit - w/ the 205s, they only need one 3mm spacer. I have run both the 225-50 on the 14x6 and 205-55 on the 14x7s. I think its a wash between the two as they are about the same width. As for how much you need to soften up the rear for the 205, I don't think you have to at all ... but then again, I have yet to run Road Atlanta w/ the 225/205 setup and I was told by a Road Atlantian that my car feels a bit more twitchy than he would like there. If you are worried, can you just disconnect the rear sway bar?
[/b]

I could see how it would be twitchy at RA with 225/205. On 225s at all 4 corners it's really neutral except for turn 11 where theres a touch oversteer. What spring rates are you running?

[Phat-S]

If you are seeing oversteer in T11 at RA, I am pretty lost.

I think the general SEDiv consensus on springrates is 400/600 or 500/700 (or something to that stagger). We ran 450-600 in 2002 and 550-700 in 2003 - both w/ a stock rear sway bar, I liked both a lot (this on revalved and shortened Koni Yellows).

[Xian]

I think as a competitor I would argue it does not pass... In my mind you can not "push" your fender out at all to get your tires to fit. If that was the case then I would be running different tires on the rear of my Audi.

If I am worng certainly tell my why/how and I could possibly be convinced to change my opinion.

Raymond "just my opinion" Blethen
[/b]
Go back and re-read my post. I didn't say that I pushed my fenders out to get the tires to fit. I was merely letting him know that if he gets too wild with rolling the inner fender lip (completely legel to roll the lip) then his fenders may get pushed out some. If they are altered beyond factory dimensions, its then his responsibility to correct the problem.

Christian, who's just sayin' what he's sayin' and nothing more.

[RSTPerformance]

If they are altered beyond factory dimensions, its then his responsibility to correct the problem.
[/b]


I think that line is an important one missing from the original post :unsure:

Thanks for adding it!!! :birra:


Raymond Blethen

[Xian]

I think that line is an important one missing from the original post :unsure:

Thanks for adding it!!! :birra:
Raymond Blethen
[/b]
I guess I understood legality to have been an understood part of building/running an IT car which caused you to see bad intentions where there were none. :D

Christian, who's got too much time and $$ tied up in IT racing to break the rules

[Catch22]

There are plenty of CRXs out there with 225/50/14 Hoosiers on the rear. We are having no problems at all on Christian's car.
The trick is that the fender lip has to be rolled pretty much flat to the inside of the rear fender well, and you need some stout rear springs (at least 600).

I can see the benefits of the staggered setup with 205s, but I wouldn't want to lose the ability to rotate back to front and visa versa.

225/45/15s also work, but the only CRX I've seen manage that trick had the rear lips done by a really good body shop with a special tool and it had big spring rates back there as well (900 I think).

[Domino]

Sorry, I meant to say turn 12. Don't blame you for being lost.

As for the "lip", are you referring to the thin metal edge that surrounds the inner fender or the 3/4 inch wide flat piece that is visible from the outside?

[Xian]

Sorry, I meant to say turn 12. Don't blame you for being lost.

As for the "lip", are you referring to the thin metal edge that surrounds the inner fender or the 3/4 inch wide flat piece that is visible from the outside?
[/b]
The "lip" is the small metal edge on the inside of the fender... in stock form there is a piece of rubber that goes over this metal edge. In race trim, you'd remove the fender liner and rubber and bend this inner edge flat against the rest of the fender. This will give you more clearance between the outside of the tire and the inside of the fender.

Christian

[Domino]

I just wanted to make sure everyone was on the same page for the definition of "lip"...mine is rolled flat. My initial issue was not that I could not get it to fit but that I could only get it to fit by putting two spacers on each wheel in order to clear the trailing arm. This caused it push it a little too far beyond the vertical plane of the fender. Since all ITA CRXs have the same dimensions, pretty much everyone using the 225 Hoosier would have the same issue. My real question is that how are people getting away with it.

[Xian]

I just wanted to make sure everyone was on the same page for the definition of "lip"...mine is rolled flat. My initial issue was not that I could not get it to fit but that I could only get it to fit by putting two spacers on each wheel in order to clear the trailing arm. This caused it push it a little too far beyond the vertical plane of the fender. Since all ITA CRXs have the same dimensions, pretty much everyone using the 225 Hoosier would have the same issue. My real question is that how are people getting away with it.
[/b]
My rear tires stick out a little bit past the vertical plane of the fender but when tested by rolling thru talcum powder, the contact patch doesn't extend past the bodywork.

I just noticed that you're in Jacksonville too... if you want to come by and take a look at my setup sometime let me know. I'll probably be in the garage some over the weekend getting everything ready for the upcoming RA race anyway.

Christian