Minimum Tire Clearance to Strut

[Al Seim]

Is there any good rule of thumb for minimum clearance from tire sidewall to strut?

Installing 225/45-13 Hoosiers for the first time on my Scirocco and not sure how much spacer to run. Obviously I'll install and check static gap but not sure how much tire deformation to allow for. Area where it would contact is smooth so light contact probably wouldn't be a big deal, but I'd still like to get it right first try.

Current setup (Kumhos) has about 3/8" clearance and does not rub. How much closer is it safe to go?

Thanks!

Al Seim
www.actdigital.com

[grjones1]

Originally posted by Al Seim:
Is there any good rule of thumb for minimum clearance from tire sidewall to strut?
Al Seim
www.actdigital.com

Al,
Put the wheel on, run a hot lap around Summit, and if you haven't punctured the sidewall, you're OK.
I know, I'm a big help, but sometimes I can't resist.
If, it helps we're well within 3/8-inch on Hoosiers (w/o spacers), and we don't rub. Of course I don't corner as fast as you, but that's another matter.
G.

[Al Seim]

GRJ:

And a great method of torquing bolts is to twist them off, then back off 1/3 turn....

Mark Coffin says 3/16" absolute min for radials - so I guess I'll shoot for 1/4" min.

Regarding cornering - after a 3 season layoff, I'll be happy if you and Danny Anderson don't lap me! Even once I'm back up to speed it'll be hard to outcorner your light Fiesta. See you at SP Labor Day weekend.

Al

[lateapex911]

Originally posted by Al Seim:
GRJ:

it'll be hard to outcorner your light Fiesta. Al

Maybe you should think about getting an ITC NB...some think it's a future overdog!

Kidding, guys, kidding...

Yes..... you can run the tires very tight to the strut. Mines not a front driver, but I run an eight or less. The resultant rubbing rare and very minimal.



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Jake Gulick
CarriageHouse Motorsports
ITA 57 RX-7
New England Region
[email protected]

[grjones1]

Originally posted by lateapex911:
Maybe you should think about getting an ITC NB...some think it's a future overdog!

Kidding, guys, kidding...

Ah, Jake, it's always sooo great hearing from you.
GRJ

[dickita15]

Originally posted by grjones1:
Al,
Put the wheel on, run a hot lap around Summit, and if you haven't punctured the sidewall, you're OK.
G.

actually while mr jones was tryng to be funny, the responce is valid.(except the puncture part) when I put on the new hoosiers I only had a 1/8". ran a session got some smoke and a rub mark on the spring mount and added spacers but there was not a mark on the tire. the sidewalls are pretty tough. I now have 3/8 static but i imagine what you can get away with would vary car to car.
dick

[This message has been edited by dickita15 (edited August 16, 2004).]

[dyoungre]

...and to add my favorite 2 cents: It's not just the tire that deflects - if you are running steel wheels (and flimsier aluminum wheels as well) the wheel center itself bends - and clearance needs to be made. Also, if you are running a car with a bolt-on bearing carrier (a so called 'live spindle') your carrier also may deflect. Hence, as Dick said, use judgement, and try reducing after dynamic testing. I also am at 1/8th with revolution wheels, no issues with rubbing (on the inside)

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Dave Youngren
NER ITA RX7 #61

[kthomas]

I like 3/8 minimum....

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katman

[grjones1]

Originally posted by dickita15:
actually while mr jones was tryng to be funny,
[This message has been edited by dickita15 (edited August 16, 2004).]

I wasn't just trying to be funny, that's the way we checked ours too. But I didn't think Al would appreciate the method. "Puncture" is so much shorter than "rub a hole in the sidewall."
GRJ

[Festus E. Simkins]

Just make sure you spin the tire on the hub after you mount it. My "crew" forgot to do that at St. Louis. I jumped in the car for the race and on the start passed 3 or 4 cars and started the turn into Turn #1. BANG! The tire looked like someone had put it on a milling machine and cut a perfect circle on the inside of the tire. No harm done but if it would have happened IN turn #1 the car would have probably be a write off. I have a little over 1/8' clearance and not rubbing. Mazda RX-7 first generation.

Drive well.