ITB CRX/Civic wheel questions

[RFloyd]

Well, now that these cars are classed in ITB where they belong, I guess everyone who was running these cars on 14x7's will have to have new wheels. I have no first-hand knowledge on the 1g CRX that I can recall since it has been about 8 years since there was one in my garage, and it never made it to become an IT car. My questions:

What offest would be best on a 14x6 wheel for these generation cars?

The car is equipped with a 4.93 FD and was run in ITA on 14x7's, so I don't want to go back to a 4.4 stock FD and 13's.

Can you fit a 225 wide tire on a 14x6 wheel?

Any help would be appreciated.

OBTW, I'll have some 14x7 wheels for sale soon.....



------------------
Richard Floyd
'86 Acura Integra LS #90
SCCA ITA / NASA ECHC H5

[R2 Racing]

Floyd,
Our ITC '85 Civic has to run 13x6's and we typically run 225/50's on them. It's not the easiest tire mounting job in the world but your typical Hoosier guys at the track should have no problem with them. We've even mounted up 225/45's on there. Our car has a 4.93FD in it too and when you put on those 225/45's, the car really spins up.

------------------
Kevin
Ruck Racing
'92 ITA Acura Integra RS
'92 ITC Honda Civic CX
'85 ITC Honda Civic S
'95 ITS Honda Prelude Si

[RFloyd]

Originally posted by R2 Racing:
Our car has a 4.93FD in it too and when you put on those 225/45's, the car really spins up.




Wow, I'll bet it does. You don't run out of legs on long straights?


------------------
Richard Floyd
'86 Acura Integra LS #90
SCCA ITA / NASA ECHC H5

[Greg Gauper]

FYI - A 225/45-13 will give you a 5th gear top end of about 117 mph with a stock ECU rev limit of 6700rpm.

A 225/50-13 gives you another 5 mph top end before you run out of revs.

A 205/60-13 is taller still.

Unless you are at a track with a looong straight, you will probably be okay with your gearing.

For a track like Road America, you would probably be okay. You might have to breath the throttle if you are in a draft going into 12, but the shorter gearing would be a plus for climbing the hills.

In my G-Prod Civic at Road America (more power than an ITB car but worse aero) I'm currently pulling 6000 in 5th gear with a 4.4 final drive on 20" slicks, which works out to about 113MPH.

[This message has been edited by Greg Gauper (edited July 22, 2005).]

[RFloyd]

Originally posted by Greg Gauper:
FYI - A 225/45-13 will give you a 5th gear top end of about 117 mph with a stock ECU rev limit of 6700rpm.

A 225/50-13 gives you another 5 mph top end before you run out of revs.

A 205/60-13 is taller still.

Unless you are at a track with a looong straight, you will probably be okay with your gearing.


That's with a 4.93 FD?


------------------
Richard Floyd
'86 Acura Integra LS #90
SCCA ITA / NASA ECHC H5

[Greg Gauper]

Yes, those numbers were with a 4.93 final drive.

The formula is in the back of the GCR.

MPH = (RPM * Tire Diameter)/(Gear Ratio * Final Drive Ratio * 336) where tire diameter is in inches.

I actually have the formula in a Spreadsheet so I can see the effect of different FD's or different tire sizes with a quick keystroke.

From Hoosier's website, I used 20.7" for the diameter of the 225/45-13 and used 21.8" for the diameter of the 225/50-13.

[This message has been edited by Greg Gauper (edited July 22, 2005).]

[RFloyd]

Originally posted by Greg Gauper:
Yes, those numbers were with a 4.93 final drive.


:Thumbsup:

A beer for you when I see you.


------------------
Richard Floyd
'86 Acura Integra LS #90
SCCA ITA / NASA ECHC H5

[RFloyd]

Originally posted by Greg Gauper:
Unless you are at a track with a looong straight, you will probably be okay with your gearing.

For a track like Road America, you would probably be okay. You might have to breath the throttle if you are in a draft going into 12, but the shorter gearing would be a plus for climbing the hills.

Longest straights I might normally see would be Road Atlanta, but then again the front straight at Roebling is long, and Lowes Motor Speedway is a possibility. Me thinks Lowes might need the 4.40 FD.

------------------
Richard Floyd
'86 Acura Integra LS #90
SCCA ITA / NASA ECHC H5

[RFloyd]

Originally posted by R2 Racing:
Floyd,
Our ITC '85 Civic has to run 13x6's and we typically run 225/50's on them.

What offset wheel do you use in order to get the 225 Hoosier inside the fender?

[MadFrog]

Originally posted by RFloyd@Jul 22 2005, 02:04 PM

Originally posted by R2 Racing:
Floyd,
Our ITC '85 Civic has to run 13x6's and we typically run 225/50's on them.

What offset wheel do you use in order to get the 225 Hoosier inside the fender?

41824


Richard, a 225 Hoosier fits on a 14x6 wheel. The tires I bought from you ages ago are currently mounted on a set of bmw 14x6 wheels. And they are about as hard as the wheels... :D

hth.

[Catch22]

Be smart about this Floyd. There are lots of benefits to the 13" size.
Lighter.
Cheaper.
Great gearing with the 4.4 FD.

The 4.9 is going to have you managing all sorts of different tire sizes for different tracks. Say... Roebling, Lowes and Daytona.
If you just install a stock 4.4 you are good to go everywhere with one tire size.

Oh, and you can get the car lower on the 225/45/13s without worrying about fender rubbing and suspension bottoming out.

I saw your new car at Road Atlanta about 3 years ago in ITA. I think it was on 205/60/13 Hoosiers.
You don't want that.
Sell the 4.9 and get your hands on a 4.4. You'll probably pocket a little money in the deal.

[RFloyd]

Originally posted by Catch22+Aug 12 2005, 01:33 AM-->
Be smart about this Floyd. [/b]

I'm trying, man, it just seems to be contrary to my nature... :rolleyes:


<!--QuoteBegin-Catch22@Aug 12 2005, 01:33 AM
There are lots of benefits to the 13" size.
Lighter.
Cheaper.
Great gearing with the 4.4 FD.

Oh, it&#39;s 13&#39;s for sure. At this point I wouldn&#39;t even consider 14&#39;s.



Originally posted by Catch22@Aug 12 2005, 01:33 AM
The 4.9 is going to have you managing all sorts of different tire sizes for different tracks. Say... Roebling, Lowes and Daytona.
If you just install a stock 4.4 you are good to go everywhere with one tire size.

Right now it looks like only 2 possible set-up choices:

225/45-13&#39;s with the 4.40 stock FD
225/50-13&#39;s with the 4.93 FD

I&#39;ve got two 4.40 FD&#39;s and a spare tranny, and the 4.93 in the box in the car.

Rigt now it just looks like a matter of figuring out which setup is better for which track. I can manage changing between races. It&#39;s not like I race every weekend, that&#39;s for sure.

The only thing that concerns me is that mathmatically the 4.40, in 4th gear and on 45 series tires, is only at 112 mph at 7000. I spoke with Blake and he mentioned in Ivan&#39;s car at Roebling they stayed in 4th all the way down the straight, and never went to 5th as the car seemed to slow down in 5th. Just too tall. So you&#39;ve hit a wall at 112. I bet RA and the long straights there is going to be the same story.

With the 4.93 and 50 series tires I think 5th might be usable, as you&#39;re at 6500rpm in 5th at 120.5mph and not even out of revs. I figure at that point (120 mph) the CRX will have hit the "aero wall." The unknown is how the 4.93 will work on the rest of the track. The question of whether the amount gained through gearing and torque multiplication is worth the time wasted shifting gears. I reallbity believe that which setup is the best is gonna be dictated by which track you&#39;re at. I&#39;d place my bets on 1 universal setup being a bit of a compromise that might leave a little much on the table. I know, I know, it&#39;s a question of finding the 10th tenth. But I do plan to be at the pointy end of the field sooner or later. Once I fine tune my mad skillz I&#39;ll need all the help from the car I can get. :rolleyes:



Originally posted by Catch22+Aug 12 2005, 01:33 AM-->
Oh, and you can get the car lower on the 225/45/13s without worrying about fender rubbing and suspension bottoming out. [/b]

I don&#39;t think that&#39;s going to be much of a cencern until I&#39;m able to score some shortened Konis. Right now I&#39;m stuck with Tokikos and the front end being a little too high in the air. We&#39;ll call that 10th tenth, part deux.



Originally posted by Catch22@Aug 12 2005, 01:33 AM
I saw your new car at Road Atlanta about 3 years ago in ITA. I think it was on 205/60/13 Hoosiers.
You don&#39;t want that.

Yer damned right about that.


<!--QuoteBegin-Catch22@Aug 12 2005, 01:33 AM
Sell the 4.9 and get your hands on a 4.4. You&#39;ll probably pocket a little money in the deal.

eh, I&#39;ll keep it, for now. I may sell it later, but I&#39;ve got a lot of learnin&#39; to do first, of tracks, car, and setups.