Tires for stock-class auto-x...?

[HEMI-Fit]

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…

[gotfitted]

Originally Posted by fitless

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…

i wouldn't suggest 225's. I run canyon's and my 215's are already rubbing and having issues. Then again i'm running 45 offset and the canyon's are a little bumpier than autox. But trust me, 215's plenty of tire for the Fit.

[HEMI-Fit]

Is it rubbing in front, back, or both?

I guess that's good to know, if a little sad. Sure would be nice to stuff a ton of tire under the Fit, but there's not much real estate to work with by it's nature. 45mm offset is too much to work in Stock, but obviously OK for some other classes - 1/4" is the max I can deviate from stock offset, and that's only 6.35mm. Call it 6.0 because they don't let you round up at all... 49mm is the max I can go.

[jayswat91]

i want to start running HS class in solo also...what kinda tires should i get...i plan on runing r-cpd tires...but i'm new in that area and i want soemthing that will last me a whole season...and something that can go on the stock fit rims...i want a size and a brand tire...thank you!!

[HEMI-Fit]

Brand? You can see several brands if you go to tirerack.com and select the "competition" option on their tire finder app. Avon, Hoosier, Toyo, Kumho, Falken... lots to choose from.

Size is the question, and what I was hoping to get some feedback on in this thread. Most 225/50-15 tires will list a 6" wheel as the minimum wheel size for that tire, but it's not a great fit. A 195/50 would probably be the best fit for a 6" wheel, but that's a lot less rubber on the ground than a 205 or 215. The 225 may be pinched so much that the contact patch doesn't end up being any wider than a smaller tire that fits the wheel better. I think with the lack of any other information, a 205/50 would probably be the best bet and easiest fit in the wheel wells and on the wheel using OEM wheels. It will lower the car slightly (0.2") and have slightly better gearing than the stock 195/55's, and they're relatively cheap because they're very popular. Search ePay for some great deals on lightly used race tires.

Regarding wear, heat = wear, but heat = grip, too. A smaller tire will heat up faster than a larger one, and could be a real advantage on a cold day. On a hot day, a tire that's too small will overheat and not grip as well. It's all a balance.

[Lyshk0]

205/50ZR15 Kumho v710 is probably the best bang for the buck for r tires. try to find some light wheels to run em on too (15x6 is a hard size to find) heres a decent resource aswell...

WHEELWEIGHTS.NET

[mrFroge]

Does anyone know the weight of the two STOCK Fit wheels (15x6 and 14x6)?

[Mr B]

I thought you had to abide with certain rules as far as UTQG tread rating goes...

[HEMI-Fit]

mrFroge, Aren't the 14" wheels 5.5" wide?

Mr B, I think the UTQG req's are in the ST* classes, like STU, STX, etc. I need to hit the rule book again to be sure, as I wasn't planning on playing there, but I *THINK* they're limited to like a 140 treadwear or something like that. The pure Stock classes, like HS, GS, DS, AS, etc can all use "R" compounds, as long as they're DOT-legal.

[Mr B]

Yeah, I haven't really read about any of the rules, but I have a lot of customers always asking me about what I would suggest for tires for 140 UTQG or up.

[Lyshk0]

Originally Posted by fitless

mrFroge, Aren't the 14" wheels 5.5" wide?

Mr B, I think the UTQG req's are in the ST* classes, like STU, STX, etc. I need to hit the rule book again to be sure, as I wasn't planning on playing there, but I *THINK* they're limited to like a 140 treadwear or something like that. The pure Stock classes, like HS, GS, DS, AS, etc can all use "R" compounds, as long as they're DOT-legal.

Originally Posted by Mr B

Yeah, I haven't really read about any of the rules, but I have a lot of customers always asking me about what I would suggest for tires for 140 UTQG or up.

fitless is right. stock class, the tires only have to be dot legal.

mr.Froge, the 15x6 i believe are 22lb. i remember reading that.

[HEMI-Fit]

I REALLYREALLY hope the OEM wheels aren't that heavy. There's been a couple threads on the topic (one just a few lines below this thread) where I thought I saw they were closer to 17 or so. Still a dang heavy wheel for it's size. The 17x8 OEM Mustang Cobra wheels I have on my Valiant are only 22-23# each...

[carlosalicea]

Originally Posted by Lyshk0

205/50ZR15 Kumho v710 is probably the best bang for the buck for r tires. try to find some light wheels to run em on too (15x6 is a hard size to find) heres a decent resource aswell...

WHEELWEIGHTS.NET

That's not what I used this year ( I used Toyo's RA1 ) But I have to agree that the V710 are the way to go. if I go back to the track I would definitively use Kumhos.

Also I had 205-50-15 RA! and they rub in the back in moderate to heavy susp compresion, my wheels are 40 offset, and have progress springs.

I have the Konig heliums and I can't think of anything better for the money.

anyway, just sharing my little experience just to help.

[Lyshk0]

heliums would be the way to go if they were 15x6 instead of 6.5

[carlosalicea]

Originally Posted by Lyshk0

heliums would be the way to go if they were 15x6 instead of 6.5

understand

[Skimmer]

I don't think the Konig Heliums come in an offset that would be legal for Stock class.

I agree with others who say the Kumho V710 is probably a good R-comp choice. They got good results in a recent test by Grassroots Motorsports. But for something cheaper, the Avon Tech R-A is also getting good comments. Probably has longer tread life, too. Now selling for $119 each in 205-50/15 from tirerack:

Avon Tech R-A

I plan to hold out for the Kumho's unless financial disaster strikes (i.e. April 15, 2008 ). The idea of using 215's front and 205s rear is appealing. I'll be using the stock Sport wheels since I haven't been able to find anything else that satisfies the rules. I plan to weigh one as soon as I get them dismounted, but most reports put the weight around 17 pounds each, which isn't terrible, but not great either.

Fitless, I'd love to see a pic of your Valiant if you get a chance. I dig old-school autocrossers! What region are you racing in, BTW?

[HEMI-Fit]

Hey, Skimmer,
I was wondering if you had found any better deals on wheels since the last time that topic came up. Ditto on the R-A's, but I just can't spring for stickies without a set of wheels to put them on, and I can't really justify pulling my Dunlops when they've only got 1200 miles on them... wife unit is tolerant, but not THAT tolerant... FWIW, some Rota's have 48mm offset, but I'm not sure you can get that offset in a 15x6. I'll have to call them and see what they can do. I like their Minilite/Panasport knockoffs for a retro kind of look. I may just go with those in a 15x7 and keep the stock wheels for autoX.

Speaking of autoX, you can see a photo of my Valiant in the "Show me your old car" threead, page 8. She's a joy to drive, but I just installed EFI on the old girl and haven't gotten it tuned yet. The new Kumho MX's on her haven't traveled more than a couple feet in the last month. Ugh. FWIW, I'm in SCCA Texas region, in the northeast (DFW) area. Lots of competitors, but light in HS - thankfully. I'm online with a bunch of other Mopar racers from coast to coast though, so if you see an old Mope at one of your local events, I may know the guy (or girl).

[Lyshk0]

i think i prolly am gonna go with the stock 15" sport wheel for autox as well, and mount some r-comps on em. i haven't had any luck finding anything usable either in a lighter weight. i will probably just get something cheap for the street.