THSCC Forums

This may be a silly question, but... Regarding alignments, does it matter what tires/wheels are on the car? I have two sets of wheels and tires and was wondering if I should put the race set on when I go for an alignment.

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Phil... Now I miss the ITR and the M3!!!
1990 Honda Civic SI

probably.

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BenchWarmer Motorsports

another one of those damn LeMons heads

just another Chump

we are an Autocross Club Dammit............

I asked Mark (HH&W) that very question and he prefers that the track/autox tires be on the car when he does the alignment.

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Rodney

'08 Bullitt mustang, CAM 7
Autox VP '09-'10, President '11-'12, interim President 2nd half of ‘14
proud recipient of the Bowie Grey service award '12
Now just a guy driving a mustang....

My personal opinion is if it's a car with more-than-stock class prep (ie. springs, lowering, camber plates, etc), then you need your race tire/wheel package on the car. If it's a stock class car where you're in the "just max everything and set the toe to this" mode, it doesn't matter.


--Donnie

Really? I can't imagine why it would matter. It's just toe, camber, and caster. You're measuring it off of a big round piece of metal bolted to the hubs.

Seriously, if someone can imagine a hypothetical example of how a different set of (straight) wheels could adjust the measurements, I'm curious to hear it...

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Mike Whitney
whit32@gmail.com, 919-454-5445
V10, V8, V8t, I6, I6, V6, F4t, I4, I4, I4, I4, I2, 1, 1

The only difference that I can see is if you ask for toe measurements in inches instead of degrees and you have wheels of different diameters.

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Has no responsibility whatsoever.

Because often on more prepared cars the race wheels/tires and street ones can be vastly different. A car will sit slightly different on a tall skinny tire and a short fat one. Different lever points and such assuming you're putting in a goodly amount of camber, anyway.

Sure, if your street and race setups are pretty similar it probably doesn't matter (as would probably be the case for a lot of ST competitors, but often not for SP or SM types).


--Donnie

Good point Donnie - I hadn't thought about the lever action of a wildly different offset.

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Mike Whitney
whit32@gmail.com, 919-454-5445
V10, V8, V8t, I6, I6, V6, F4t, I4, I4, I4, I4, I2, 1, 1

I've seen cases where a funky tread pattern (mostly from uneven wear across the surface of the tire) can throw off alignment readings. I tend to agree with Donnie-- if the tires are close and don't show any signs of unusual wear, don't worry about it. If not, use the wheels/tires you will be running during competition for the alignment process.

Jim

Oh, I'd also add one thing...you're only looking for relative alignment numbers anyway. As in "I want the same as last time" or "I want a .5 more degrees of negative camber than last time" or whatever. So in that sense it's really more important to get alignments done with the *same* setup every time. Otherwise you could be varying the alignment a little and not really know it...


--Donnie

Interesting comments. I think what Mike was saying applies to most of us. We're not concerned with the MINUTE details. Either way, I'll probably put the autocross setup on just in case. Crazy thing is that I'm probably going to get different size tires later this year than what I'm currently running.

Thanks for the comments.

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Phil... Now I miss the ITR and the M3!!!
1990 Honda Civic SI