right now i have two sets of rims
one set being 15*7 with 205/50/15 T1-S, and another set being 15*6.5 with 195/50/15 T1-S

i'm thinking of running the 15*7's up front with the 15*6.5's
i know this is a popular theme in Japanese racing series but what do you guys think?

i can think of the pro's being
-increasing front track
-promote more rotation

but i can't think of any con's

thoughts?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Steady &raquo;</TD></TR><TR><TD CLASS="quote">
but i can't think of any con's

</TD></TR></TABLE>

You can't rotate your tires front/back.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by buji &raquo;</TD></TR><TR><TD CLASS="quote">

You can't rotate your tires front/back.</TD></TR></TABLE>


why can't you??

just different sized tires.....


i ran 225/50/15 up front
205/50/15 rear

600 front 700 rear spring rates

didn't ahve a problem with it....

 

I have been running 9.5x20x13 front slicks and 8x20x13 rear slicks for the last four seasons on my SCCA GT4 CRX and I like the way it works. I am using the same width rim front and rear but I don't see why it wouldn't work for you.


Modified by keithg at 5:31 AM 3/7/2004

 

at one autocross I ran 225/40-18 Yokohama AVS ES100s in the front, and my stock 195/65-15 All-season michelins in the rear, just for the hell of it

Actually, I though I might try it out, especially since I destroyed my other two 18" wheels in an accident a few weeks earlier. I won't be trying that again (looked soooo stupid)

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by chad &raquo;</TD></TR><TR><TD CLASS="quote">

why can't you??
</TD></TR></TABLE>

Well, you could. But if you did you would obviously end up running the narrower tires up front at some point. Am I not understanding the question?

I used to run 225/50/15's front and 205/50/15's rear in the DS ITR, but I never ran into any rotating issues because I started out with two complete sets of 4 in each size.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Steady &raquo;</TD></TR><TR><TD CLASS="quote">i can think of the pro's being:
-increasing front track
-promote more rotation
- thoughts?</TD></TR></TABLE>

There are many people running the same size tire F/R, who are also very fast around the track.
Staggering tires sizes will most likely produce more rotation, but I think you want the back end to 'slip' (if you will) in a predictable manner, and also be "catchable" if necessary - you don't want to reduce your overall cornering speed just to keep the car 'in check' (think fast sweeper). It may take a lot of experimenting to keep you ultimate level of grip the same.

[my opinion]

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Steady &raquo;</TD></TR><TR><TD CLASS="quote">
but i can't think of any con's</TD></TR></TABLE>

I forgot to mention, with my setup there was a significant weight difference between the 205's and the 225's. Having extra weight on the drive wheels is certainly a con. In the ITR I think the added grip was worth the acceleration/deceleration changes from a heavier front wheel/tire combo, but it's still a consideration for a more underpowered car.