> So I
> gave what was left of my 245/45/17 Kumhos to James.
thank you both mr generositys!! they are in my shed awaiting use.
-james
----- Original Message -----
From: Thana, Peter {High~Palo Alto} <PETER.THANA@ROCHE.COM>
To: 'Mike Eynon' <stingray@onth.com>; <ba-autox@autox.team.net>
Sent: Thursday, April 26, 2001 2:44 PM
Subject: RE: M3 tire question
> Hi Mike,
>
> Perhaps I can shed a little light on your dilemna. I run a '99 Z3 2.8
Coupe
> which came stock with 16x7 rims all around, but which had factory option
> 17x7.5F/17x8.5Rs, identical to the staggered E36 M3 setup. When I first
> went to Kumhos, I bought a set of staggered E36 M3 wheels and mounted
> 225/45/17F and 245/45/17R Kumhos on them. If you look at the data sheet
on
> TireRack, the claimed outside diameter for the 245/45s is only 0.1" larger
> than the 225/45. So I bought them thinking it wouldn't be a big deal,
since
> they were supposedly sized closer to a 245/40. Well, in reality they are
a
> good 0.6" larger in diameter than the 225/45s, so don't go off their
> published specs!
>
> Anyway, I wasn't very happy with this setup as the rears were too big,
which
> had four major disadvantages:
>
> 1) taller gearing
> 2) extremely heavy, even on the forged E36 LTW rim (50lbs total on a 22lb
> rim = ~28-29lbs of tire, ouch!)
> 3) even harder to fit inside my car for transport (yes, 4 tires do barely
> fit in the Coupe)
> 4) wider rear tires useless on a car that understeers like mad to begin
with
>
> So there were two options, go 225/45 front and 255/40 rear, or 225 all
> around. I wasn't too crazy about the first option, because it made
problems
> 2, 3, and 4 even worse. So I was all set to go with 225/45/17s all
around,
> which, as crazy as it seems, would probably work really well.
>
> Anyway, I didn't end up doing that in the end because of a very generous
> fellow competitor who shall remain nameless. Turns out said person, who I
> shall refer to as "Mr. Generosity" runs his Kumhos on the street and
doesn't
> want to risk running them too far past the wear bars. These nice shaved
> tires happened to be 245/45/16s, which fit my old 16x7 rims. So thanks to
> "Mr. Generosity", I am back to running nice fat tires same size around and
> they are small enough to fit in my car with tons of space to spare! So I
> gave what was left of my 245/45/17 Kumhos to James.
>
> Anyway, I'm getting a bit off topic here, but my point is that I don't
think
> it's such a bad idea to try 225s all around. I can't be sure that they
will
> fit the wide 8.5" rear rim, as the Kumho published specs are slightly
hokey.
> For example, my 245/45/16 V700 casing is about as wide as my 245/45/17
> Bridgestone RE730 street tire, but the tread is wider on the Kumho. The
> 225s are about 0.5 inches narrower as advertised. Our BMWs are probably
> very neutral at track speeds, but for autocross they have a bit of low
speed
> understeer. If you can't get a wider front tire on there I don't see what
> good a wider rear will do. Also, if you plan on running some of the SFR
> events at Golden Gate Fields, the 225s might even work better because that
> surface doesn't warm the tires up much.
>
> The disadvantage is that the M3 has more power and torque than my 2.8, and
> so it might be harder to get power down on corner exit. But if your 245s
> aren't even getting warm, then that might not be the limiting factor.
Hard
> to say, but you might want to try it. Good luck!
>
> Peter
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