Autocross - Tire Damage
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Driver Carries No Cash
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From: Tampa, Florida
Autocross - Tire Damage
This weekend my wife and I drove in a PCA autocross. This was my second autocross with my Potenza S-02's on the car. Three months ago, I bumped up to a 225x?x17 width tire up front. I soon discovered that i'd get a bit of rub inside the fender well under extreme loads. (Like "dive-bombing" into traffic on a downhill off-camber intersection <img border="0" title="" alt="[Wink]" src="wink.gif" /> ) The autocross course we drove had a couple of brutal left handers that really compressed the right front corner of the car and we could hear the car rub.
Sunday afternoon, I cleaned the car up and yanked all four wheels off for an inspection. We rubbed a nice sized hole through some of the undercoating. (That stuff is really thick in places!) We also rubbed a nice little hole into a section of plastic fender lining (big deal). We managed to rub enough undercoating off to expose a nice sharp corner that started to dig into the tire. Thankfully, damage to the tire was pretty light. ....good thing we didn't have any more runs, I probably would have really done some damage once that piece was exposed.
I dropped the car off at the garage this morning for a bunch of services. (Good topic for another thread) On my list of service items, I've asked the shop to take a look at the suspension and make me a recommendation.
The easy answer is to use a smaller tire. Bah! Big Rubber Good, Small Rubber Bad!
(Especially when purchasing prophylactic's! <img border="0" alt="[icon501]" title="" src="graemlins/icon501.gif" /> )
We might be able to use a wheel spacer and roll the fender lip to give a little more clearance inside the fender well.
I've wondered if they can lower the spring perch and let the car ride a little higher giving a little more room. I'm afraid that will throw out the corner balancing and alignment though.
Anyone else care to share a similar experience with 225's up front?
Sunday afternoon, I cleaned the car up and yanked all four wheels off for an inspection. We rubbed a nice sized hole through some of the undercoating. (That stuff is really thick in places!) We also rubbed a nice little hole into a section of plastic fender lining (big deal). We managed to rub enough undercoating off to expose a nice sharp corner that started to dig into the tire. Thankfully, damage to the tire was pretty light. ....good thing we didn't have any more runs, I probably would have really done some damage once that piece was exposed.
I dropped the car off at the garage this morning for a bunch of services. (Good topic for another thread) On my list of service items, I've asked the shop to take a look at the suspension and make me a recommendation.
The easy answer is to use a smaller tire. Bah! Big Rubber Good, Small Rubber Bad!
(Especially when purchasing prophylactic's! <img border="0" alt="[icon501]" title="" src="graemlins/icon501.gif" /> )
We might be able to use a wheel spacer and roll the fender lip to give a little more clearance inside the fender well.
I've wondered if they can lower the spring perch and let the car ride a little higher giving a little more room. I'm afraid that will throw out the corner balancing and alignment though.
Anyone else care to share a similar experience with 225's up front?
Burning Brakes
Joined: Jun 2001
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From: Texas
I've noticed a little rubbing on the inside using 225's up front as well. 1/4 inch spacers would be the easiest solution. I've used them once but was uncomfortable with the amount of thread holding the lugnut. I'm going to install longer studs and go to steel, open ended lugnuts.
You mentioned rolling the fender lip. I've never noticed any rubbing being caused by the outer edge of the tire. Is this what you're getting?
Also, are you running 16's or 17's? I've been using 16's and just bought a set of 17 inch rims. I noticed that the 225 tires in 17's are actually wider than the 225's in 16's. If you're running 17's now, it sounds like I may be getting even more tire rub going from 16 to 17.
You mentioned rolling the fender lip. I've never noticed any rubbing being caused by the outer edge of the tire. Is this what you're getting?
Also, are you running 16's or 17's? I've been using 16's and just bought a set of 17 inch rims. I noticed that the 225 tires in 17's are actually wider than the 225's in 16's. If you're running 17's now, it sounds like I may be getting even more tire rub going from 16 to 17.
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The tires aren't hitting the outside fender lip. I'm rubbing the inside of the fender well up near the shock mount. I'm afraid that if I put in spacers I'll push the tires to the very edge of the fenders and I'll just transfer my problem from the inside of the fender well to the outside. I thought of rolling the fender as a precautionary move. I'm not sure it's entirely necessary. I'd rather roll it now than head to the body shop with a bent fender after my next autocross.
Drew - to your point about spacers. Adrian has often recommended in this group that you use longer studs in combination with wheel spacers. So it sounds like your on the right track.
Yes, I am using a set of 17" 993 cup wheels on my car. (I love those wheels!) If you've made the move to 17's you too might run into the same thing, but then again everyone's car is different. I'm sure that a lot depends on how you've got your suspension setup.
Autocross is really rough on your car. Running your car hard on a real race track is far less traumatic on your equipment than autocross. You get a lot higher lateral G-loading on a race track, but on an autocross you're fully compresing that suspension corner after corner and you really scrub your tires.
...at least if you drive like I do! <img border="0" alt="[burnout]" title="" src="graemlins/burnout.gif" />
Drew - to your point about spacers. Adrian has often recommended in this group that you use longer studs in combination with wheel spacers. So it sounds like your on the right track.
Yes, I am using a set of 17" 993 cup wheels on my car. (I love those wheels!) If you've made the move to 17's you too might run into the same thing, but then again everyone's car is different. I'm sure that a lot depends on how you've got your suspension setup.
Autocross is really rough on your car. Running your car hard on a real race track is far less traumatic on your equipment than autocross. You get a lot higher lateral G-loading on a race track, but on an autocross you're fully compresing that suspension corner after corner and you really scrub your tires.
...at least if you drive like I do! <img border="0" alt="[burnout]" title="" src="graemlins/burnout.gif" />
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I found some 1/8" spacers in a catalog several years ago, but can't remember which catalog. You shouldn't need longer studs using a 1/8" spacer. I also rolled the fender lips, but having a body shop cut them back to about 1/16" to 3/32" is probably better (I've had done it both ways).
King of Cool
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</font><blockquote><font size="1" face="Verdana,Tahoma,Arial,Helvetica,Geneva">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">Originally posted by C4 Guy:
<strong>...Autocross is really rough on your car. Running your car hard on a real race track is far less traumatic on your equipment than autocross. You get a lot higher lateral G-loading on a race track, but on an autocross you're fully compresing that suspension corner after corner and you really scrub your tires.
...at least if you drive like I do! <img border="0" alt="[burnout]" title="" src="graemlins/burnout.gif" /> </strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">Terry,
When you do your first track day, you might think that again...
BTW, it was nice to see you again & sorry to hear about your engine problems. FVD guys are doing the repair?
<strong>...Autocross is really rough on your car. Running your car hard on a real race track is far less traumatic on your equipment than autocross. You get a lot higher lateral G-loading on a race track, but on an autocross you're fully compresing that suspension corner after corner and you really scrub your tires.
...at least if you drive like I do! <img border="0" alt="[burnout]" title="" src="graemlins/burnout.gif" /> </strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">Terry,
When you do your first track day, you might think that again...
BTW, it was nice to see you again & sorry to hear about your engine problems. FVD guys are doing the repair?
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Thanks Pete - glad to see you "slumming" with us autocrossers!
For the benefit of our fellow Rennlisters, I'll give you guys a bit of background. The Goldcoast Region of the PCA, which covers South Florida, only manages to get a mediocre turnout for our autocrosses (Drivers Ed's are a big hit though!). It seems the same bunch of guys show up month after month with little new blood. Therefore, the scores are practically predictable based on who's in attendance. I was feeling all smug last week knowing that the guy that always takes first place in my class was going to be out of town. I thought I had a really good shot at that 1st place trophy.
....but then the Flying Finn shows up in his bad-@$$ 993. The Finn never shows up for autocross - they're too small for him, but with no D.E.'s on the calendar, he comes out for a little autocross fun. So this "stranger" comes to our little tight knit autocross group and proceeds to hand us our collective @$$es as he goes home with a class win and fastest time of the day! <img border="0" alt="[cheers]" title="" src="graemlins/beerchug.gif" />
P.S. Yes, I'm having the FVD/Gulf Performance guys take care of the car!
For the benefit of our fellow Rennlisters, I'll give you guys a bit of background. The Goldcoast Region of the PCA, which covers South Florida, only manages to get a mediocre turnout for our autocrosses (Drivers Ed's are a big hit though!). It seems the same bunch of guys show up month after month with little new blood. Therefore, the scores are practically predictable based on who's in attendance. I was feeling all smug last week knowing that the guy that always takes first place in my class was going to be out of town. I thought I had a really good shot at that 1st place trophy.
....but then the Flying Finn shows up in his bad-@$$ 993. The Finn never shows up for autocross - they're too small for him, but with no D.E.'s on the calendar, he comes out for a little autocross fun. So this "stranger" comes to our little tight knit autocross group and proceeds to hand us our collective @$$es as he goes home with a class win and fastest time of the day! <img border="0" alt="[cheers]" title="" src="graemlins/beerchug.gif" />
P.S. Yes, I'm having the FVD/Gulf Performance guys take care of the car!
King of Cool
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</font><blockquote><font size="1" face="Verdana,Tahoma,Arial,Helvetica,Geneva">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">Originally posted by C4 Guy:
<strong>....but then the Flying Finn shows up in his bad-@$$ 993. The Finn never shows up for autocross - they're too small for him, but with no D.E.'s on the calendar, he comes out for a little autocross fun. So this "stranger" comes to our little tight knit autocross group and proceeds to hand us our collective @$$es as he goes home with a class win and fastest time of the day! <img border="0" alt="[cheers]" title="" src="graemlins/beerchug.gif" />
P.S. Yes, I'm having the FVD/Gulf Performance guys take care of the car!</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">Terry, you know what they say (in motorsports): "If you want to win, take a Finn"
It was just 'beginners luck'.
I'm glad I could change you typical score boards for a change (which wasn't doo for you though...).
Good to hear FVD is taking care of your baby.
BTW, about that other thread (engine detailing), since your engine will be out, it's a great chance to get rid of that engine compartment sound deadening.
<strong>....but then the Flying Finn shows up in his bad-@$$ 993. The Finn never shows up for autocross - they're too small for him, but with no D.E.'s on the calendar, he comes out for a little autocross fun. So this "stranger" comes to our little tight knit autocross group and proceeds to hand us our collective @$$es as he goes home with a class win and fastest time of the day! <img border="0" alt="[cheers]" title="" src="graemlins/beerchug.gif" />
P.S. Yes, I'm having the FVD/Gulf Performance guys take care of the car!</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">Terry, you know what they say (in motorsports): "If you want to win, take a Finn"
It was just 'beginners luck'.
I'm glad I could change you typical score boards for a change (which wasn't doo for you though...).
Good to hear FVD is taking care of your baby.
BTW, about that other thread (engine detailing), since your engine will be out, it's a great chance to get rid of that engine compartment sound deadening.
