ITA CRX: Tires

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11-01-2009, 08:11 PM
280ZX3

ITA CRX: Tires

My race team is going to be running two '91 ITA CRXs next year and we've decided to make the jump from 14x6s to 15x7s. We're currently running 205/55/14 Kumho V710s on the 14s. We're kind of on a budget and looking to get the most bang for the buck.

We would run 225/45/15 V710s, but Kumho doesn't make that size. Hoosier, Toyo, and Nitto do.

The problems as I see them:

Kumho- Can only run Kumhos in 205/50/15s. 20 mm of tread seems like a lot to give up.
Hoosier- $217 a piece. $50 more per tire than other tires in its class. They also don't last as long, but are probably the fastest.
Nitto NT-01 - Are they as fast as V710s? Looks like they probably should be shaved.
Toyo R888 - Same problem as Nittos.

Can anyone give us any suggestions? If anyone has made the jump from 205s to 225s on an ITA Honda, I'd be interested to see how much of a difference it actually made in lap times.

By the way, we're not opposed to the 14x7 option either, but I'm having a really hard time finding any 14x7 Honda rims.
11-02-2009, 08:38 AM
joeg

Seem if you are on a "budget" why change to a more expensive size?

If you are not strictly budgeted and you really want to see what the car can do--GO HOOSIER!!
11-02-2009, 11:07 AM
mc-integra111

Quote:

Originally Posted by 280ZX3

We would run 225/45/15 V710s, but Kumho doesn't make that size. Hoosier, Toyo, and Nitto do.

So either run the 225/50R14 V710's or pick a different final gear and run the 225/50R15's. I actually run both of these sizes to purposely change my effective final gear.

Quote:

Originally Posted by 280ZX3

If anyone has made the jump from 205s to 225s on an ITA Honda, I'd be interested to see how much of a difference it actually made in lap times.

Not that much. I'd say I only gained a couple tenths or so (205 on 6" wide to a 225 on 7" wide). I do not have data to back that up as other change were made to a larger overall improvement, so that is just my best guess. Plus, I am not convinced I have the most correct setup yet, so take this for what it's worth.

Quote:

Originally Posted by 280ZX3

By the way, we're not opposed to the 14x7 option either, but I'm having a really hard time finding any 14x7 Honda rims.

Try Team Dynamics. I use the ProRace 1.2.
11-02-2009, 03:05 PM
280ZX3

Quote:

Originally Posted by mc-integra111

Not that much. I'd say I only gained a couple tenths or so (205 on 6" wide to a 225 on 7" wide). I do not have data to back that up as other change were made to a larger overall improvement, so that is just my best guess. Plus, I am not convinced I have the most correct setup yet, so take this for what it's worth.

I'm surprised. I thought it would have been a substantial increase. Perhaps the money would be better spent developing other areas of the car.
11-02-2009, 05:28 PM
Steam Corners

Quote:

Originally Posted by 280ZX3

By the way, we're not opposed to the 14x7 option either, but I'm having a really hard time finding any 14x7 Honda rims.

I think I saw a 14x7 Enkei RPF-1 in the most recent Tire Rack ad in Grassroots. . I'm having issues finding pricing on their site right now, however. . .
11-02-2009, 06:30 PM
mc-integra111

Quote:

Originally Posted by 280ZX3

I'm surprised.

I was too. I know a guy (preps 2 CRX's) who swears they aren't worth anything (well, not enough grip to overcome extra rotating mass and rolling resistance) and still runs 205's.

My suggestion would be to keep running 205's on 6" until you get to a point where you want to go out and try to win each weekend. At that point, the small amount of extra grip is worth whatever it costs.
11-02-2009, 07:03 PM
280ZX3

Quote:

Originally Posted by mc-integra111

I was too. I know a guy (preps 2 CRX's) who swears they aren't worth anything (well, not enough grip to overcome extra rotating mass and rolling resistance) and still runs 205's.

My suggestion would be to keep running 205's on 6" until you get to a point where you want to go out and try to win each weekend. At that point, the small amount of extra grip is worth whatever it costs.

Interesting. Thanks for the info.

By the way, we'll probably see you next year at a MCSCC event. We run the black/yellow #39 ITA CRX (Bryan Leslie W2W's it) and now we've added the white/blue #36 ITA CRX that used to belong to Donny Kovar. It will be fun having two of our W2W drivers in the same class.
11-03-2009, 10:50 AM
mc-integra111

I was wondering. I was talking with Doc about wheels for the CRX at the last Autobahn race when you guys were looking at Kovar's car.

Look forward to seeing you guys out next year.
11-04-2009, 11:33 AM
Xian

Hoosiers really don't have the horrible wear many folks insist that they do. That all went away when they released the R3SO5's. The current crop of 06's run really well up to around 12-ish heat cycles at which point they begin to fall (comparitively) but stay consistent until around cycle 20-22 at which point they get harder and don't "work" as well and sometimes have difficulty coming up to temp.

I've always run 225's on my ITA CRX and now my ITA Civic. More rubber is never a bad thing and at the very least it gives you more mass to handle the heat loads FWD can dish out. I've got no idea what sort of time difference you're talking about with 205 vs 225 but, based on other faster/more experienced drivers (Fowler, Moser, Nealey, etc, etc), I think you're fooling yourself if you don't think they wider tires are faster.

I run the 14x7 Team Dynamics wheels. They work fine and hold up well. There are other lighter and more expensive options options there too (Volk comes to mind).

BTW, 225/50 14's just barely fit on a CRX... especially tight on the rear. Completely aside from the gear ratio issues, a 225/50 15 is going to be too tall for the CRX. This will either cause bottoming out in the wheel well at the correct ride height or you'll have to increase the ride height to keep from bottoming out. IMO, this would be a way worse compromise than just running the wheel/tires that you've got right now.
11-04-2009, 01:58 PM
Ed Funk

I agree completely with Christian, in regards to wear of Hoosiers, and the size issue on the CRX. At correct ride height 225/50x14 is the max that will fit. the bigger tire will go longer in the race before it starts falling off from FWD heat issues.

Just don't ask Christian about his poop chute!
11-04-2009, 11:18 PM
Xian

Well... ya' see it's got a 6" diameter and... :eek::D
11-05-2009, 07:06 AM
ozal92

Quote:

Originally Posted by Ed Funk

I agree completely with Christian, in regards to wear of Hoosiers, and the size issue on the CRX. At correct ride height 225/50x14 is the max that will fit. the bigger tire will go longer in the race before it starts falling off from FWD heat issues.

Just don't ask Christian about his poop chute!

What about a 225/45/15? I'm seeing more and more H4 crx's/integra's running that size as well? Should be the same as a 225/50/14, no?
11-09-2009, 09:38 PM
Xian

The H4 cars use that b/c they're on Spec Toyo's. You can fit a 225/45 Hoosier R6 on a CRX but it is sooooo amazingly tight you'll damn near kill yourself trying to get enough clearance on the LCA without hitting the fender all while keeping a decent ride height and finally, keeping the tire under the fenders so it's legal.

Apples meet Oranges.