Tires for stock-class auto-x...?
#81
08-01-2008, 02:43 PM
Now that I’ve got my Fit, I’m looking at what it’s going to take to play in H Stock SCCA autoX. I’ve run a few times in SM with my old 87 Daytona (engine, wheels, and brake upgrades), and my 69 Valiant is set up to play in SM as well. Although I’m fairly familiar with Solo II in general, the Stock classes were never a possibility for me until now.
My plans at this point are to upgrade tires to something sticky on the stock 55mm (ugh) offset wheels, and eventually upgrade the shocks/struts at some time down the road. My question is this: what’s the consensus on tire sizing for HS autoX use? I know that typically the goal is to squeeze as much tire on to a wheel as you can fit under the car, unless there’s a clear indicator that the extra tire width just doesn’t work. Is that still the case with the Fit? The two basic scenarios I’m looking at are same-size tires front and rear, or wider tires up front and narrower tires in back. Sizes I’m considering are generally 205/50, 215/50, or 225/50.
If someone has already tried a 225/50 on the stock wheels and found no real benefit, I’ll skip that project. I’m almost certain that they won’t fit in back without spacers, and I’m not sure if ¼” will be enough to keep them from rubbing the shocks. I think they’d be OK in front, and that might help minimize understeer if using a 205 in back.
Any sage advice or experiences welcome…
My plans at this point are to upgrade tires to something sticky on the stock 55mm (ugh) offset wheels, and eventually upgrade the shocks/struts at some time down the road. My question is this: what’s the consensus on tire sizing for HS autoX use? I know that typically the goal is to squeeze as much tire on to a wheel as you can fit under the car, unless there’s a clear indicator that the extra tire width just doesn’t work. Is that still the case with the Fit? The two basic scenarios I’m looking at are same-size tires front and rear, or wider tires up front and narrower tires in back. Sizes I’m considering are generally 205/50, 215/50, or 225/50.
If someone has already tried a 225/50 on the stock wheels and found no real benefit, I’ll skip that project. I’m almost certain that they won’t fit in back without spacers, and I’m not sure if ¼” will be enough to keep them from rubbing the shocks. I think they’d be OK in front, and that might help minimize understeer if using a 205 in back.
Any sage advice or experiences welcome…
And disconnect the front antisway bar; you'll need to keep the inside front tire on the ground. The Fit goes best with better cornering and that means better rotation and traction. In H everything outaccelerates a Fit regardless so you need every cornering advantage you can get.
Last edited by mahout; 08-01-2008 at 02:46 PM.
#82
08-02-2008, 05:03 PM
You can pretty much run any tire that will fit on the stock-size wheels and be OK. Full slicks, OK. R-comps, OK. Studded snow tires, OK. As long as they don't require reworking your stock wheel openings, you're good.
HF
HF
#83
08-02-2008, 05:54 PM
Just remember they must be DOT approved and NOT on the SCCA's Solo excluded tire list.
#84
08-02-2008, 11:43 PM
Excellent point, mrFroge. Although I don't think there are any excluded tires on the stock class list in the 2008 rules, I think there have been in the past few years due to brand new tires not being out long enough or something like that. Looks like outright SLICKS may not be legal, according to 13.3(H) "Each tire must have non-zero measureable tread tepth (i.e., points where it is possible to obtain positive measurement values) as described in 3.3.3.B." There's certainly a lot more to choosing a set of R-comps than I know about, having never used anything but some sticky Bridgestones and some Kumho MX's. I'm sure mrFroge, MINI-Fit, Skimmer, or Mahout can chime in with the goods, though.
HF
HF
#85
08-03-2008, 08:09 AM
[quote=HEMI-Fit;384323]Excellent point, mrFroge. Although I don't think there are any excluded tires on the stock class list in the 2008 rules, I think there have been in the past few years due to brand new tires not being out long enough or something like that. Looks like outright SLICKS may not be legal, according to 13.3(H) "Each tire must have non-zero measureable tread tepth (i.e., points where it is possible to obtain positive measurement values) as described in 3.3.3.B." There's certainly a lot more to choosing a set of R-comps than I know about, having never used anything but some sticky Bridgestones and some Kumho MX's. I'm sure mrFroge, MINI-Fit, Skimmer, or Mahout can chime in with the goods, though.
Our 'professional' A/Xer's say that rule eliminates slicks. And that there are local rules that stock class vehicles must use tires with treadwear ratings in excess of 100, or even more. We have heard there's a club in VA or SC that requires at least 200. Sounds good to us. Stock classes aren't intended for such specialization.
Our 'professional' A/Xer's say that rule eliminates slicks. And that there are local rules that stock class vehicles must use tires with treadwear ratings in excess of 100, or even more. We have heard there's a club in VA or SC that requires at least 200. Sounds good to us. Stock classes aren't intended for such specialization.
#86
08-28-2008, 08:20 PM
anybody run this setup on stock wheels?
Front: 1/4" spacers with 225/45R15
Rear: no spacers with 205/50R15
presumably these would be hoosiers since that's the only r-comps that come in both sizes.
do the fronts rub? how's the balance with this staggered setup?
Front: 1/4" spacers with 225/45R15
Rear: no spacers with 205/50R15
presumably these would be hoosiers since that's the only r-comps that come in both sizes.
do the fronts rub? how's the balance with this staggered setup?
#87
08-28-2008, 09:41 PM
I am in about the same position. I just scored a pair of used Hoosiers in 205 50 15 and plan to run them in the front on Saturn rims and run my Falken rt-615 205 50 15 in the rear on stock rims with the Monroe air shocks in the rear as well. I'm concerned about the rear clearance with the Monroes back there. When I get them mounted next week I will let the group know what I find out. I will measure the width difference between the Hoosiers and the Falkens(if any)to make sure my info is useful to you.
#89
08-28-2008, 10:06 PM
Should make the car rotate quite nicely. Falken vs sp31 has worked out quite well so I figure this is worth trying. Mahout will be happy as I plan to also disconnect the front swaybar as well.
#91
08-28-2008, 10:21 PM
As usual its always a matter of Money vs Time. I have the money now for the two I found and hopefully the time to get them here before next weekend. I have a few more weeks to fine two more and sell a few more things on ebay to pay for them. I let you know how it works out. As long as its not a total disaster I should be happy.
#93
08-28-2008, 10:29 PM
It would depend on what I can find used in the next few weeks and if anyone can confirm they will fit. I know the 205 50 will fit based on my Falkens so if in doubt I will stick to that size. I will be using the Saturn rims which are the max offset so no spacers. Going to sleep now.
#96
08-28-2008, 11:06 PM
dj,
I don't think you'll have any problems with the 225/45 on the front. I ran a set of 225/50's all around on my Saturn wheels while finding out just how wide I could go under real-world driving conditions. They'll rub the shock dust boots in back, but I never noticed any rubbing in front. A slightly shorter aspect ratio would only help things, IMHO. I'm actually thinking about using those as well in a staggered setup, once I'm able to get some seat time and can justify the expense. I've got a pair of Victoracers for the front that I'll use next time I'm able to get out on track.
HF
I don't think you'll have any problems with the 225/45 on the front. I ran a set of 225/50's all around on my Saturn wheels while finding out just how wide I could go under real-world driving conditions. They'll rub the shock dust boots in back, but I never noticed any rubbing in front. A slightly shorter aspect ratio would only help things, IMHO. I'm actually thinking about using those as well in a staggered setup, once I'm able to get some seat time and can justify the expense. I've got a pair of Victoracers for the front that I'll use next time I'm able to get out on track.
HF
#97
08-28-2008, 11:13 PM
dj,
I don't think you'll have any problems with the 225/45 on the front. I ran a set of 225/50's all around on my Saturn wheels while finding out just how wide I could go under real-world driving conditions. They'll rub the shock dust boots in back, but I never noticed any rubbing in front. A slightly shorter aspect ratio would only help things, IMHO. I'm actually thinking about using those as well in a staggered setup, once I'm able to get some seat time and can justify the expense. I've got a pair of Victoracers for the front that I'll use next time I'm able to get out on track.
HF
I don't think you'll have any problems with the 225/45 on the front. I ran a set of 225/50's all around on my Saturn wheels while finding out just how wide I could go under real-world driving conditions. They'll rub the shock dust boots in back, but I never noticed any rubbing in front. A slightly shorter aspect ratio would only help things, IMHO. I'm actually thinking about using those as well in a staggered setup, once I'm able to get some seat time and can justify the expense. I've got a pair of Victoracers for the front that I'll use next time I'm able to get out on track.
HF
#98
08-29-2008, 12:29 AM
Wider is better... sounds familiar, didn't Pontiac use that for the Grand-am widetrack back in the 90's 
ok, back on topic! Here is a blurb I read somewhere which is why I asked the question.
Is there maybe certain types of spacer that are better than others?
ok, back on topic! Here is a blurb I read somewhere which is why I asked the question.
My first NSX ('91) had spacers installed on the rear wheels to allow wheels with the wrong offset to be installed. After I had owned the car for a few months I heard a rattle comming from my right rear wheel. When I opened up the lug cover I found a lug nut with a piece of the stud rolling around in there (broken off!!) the rest of the lug nuts, I discovered required only 3 turns to be torqued!!! The spacers I had were just a 10mm washer like piece of metal with holes drilled to
match the lug pattern. This arrangement eliminated the "hub centric" design of the wheel and put the lug studs in a shear loading condition (they are only designed for tension). If you do use spacers make sure they are designed to attach to the hub and transfer the "hub centric" out to the wheel and not just act like a washer. Also make sure that you will have enough grip length on your lug nuts (at least filled with stud).
match the lug pattern. This arrangement eliminated the "hub centric" design of the wheel and put the lug studs in a shear loading condition (they are only designed for tension). If you do use spacers make sure they are designed to attach to the hub and transfer the "hub centric" out to the wheel and not just act like a washer. Also make sure that you will have enough grip length on your lug nuts (at least filled with stud).
#99
08-29-2008, 08:51 AM
You make a good point with the hub centric issue. I've had the same reservations about the Saturn wheels which have a different center hole than the Fit and rely on the wheel studs to center the rim. Perhaps higher strength studs such as ARP studs are in order if you remove the hub centric feature.
#100
01-08-2012, 04:13 AM
Sorry to bump an old thread but I didn't want to start a new one.
So basically my plan is to run 205/50R15 on the stock wheels for the upcoming season of Auto-X. It seems like it should be fine but I want to make sure no one had any real rubbing issues as we have a couple VERY tight tracks.
Thanks for the help and my dumb over questioning in this matter. First year racing the Fit previously I raced my other two cars.
So basically my plan is to run 205/50R15 on the stock wheels for the upcoming season of Auto-X. It seems like it should be fine but I want to make sure no one had any real rubbing issues as we have a couple VERY tight tracks.
Thanks for the help and my dumb over questioning in this matter. First year racing the Fit previously I raced my other two cars.