I have a 2010 Mini Cooper and I heard that the winning nationals H-stock driver had tires as wide as 225 on the car. Is that even possible? how wide a wheel would I need if it is possible?

 

I would also like to know since I want the widest possible tires without cutting or it sticking so far out from the fender flares. Getting spacers would be an OK option to get a little wider as well

 

Can't speak to the H-stock setup but the D-stock minis run 235 Hoosiers. They will rub on the rear trailing arm but not too bad. You just have to deal with it.

 

The wheel width is constrained by the rules for the class of course... and spacers are not kosher.

I'm running 16x7 with 205/45 Hoosiers which works very nicely indeed.

Cheers,

Charlie

 

The MINI's that are using a 225/45/15 are running them on the OEM 15x5.5" wheel. Here's the catch...

The tires are Hoo$ier A6's (R-Comp) and they are stiff enough regarding their sidewall construction that they can be pinched on a much narrower wheel. People have been utting the 275/35/15 on the OEM TypeR's 6" wheel for years now... You can't pinch street tires like that.

However, the SCCA is on the verge of historic Stock class restructure that will basically kill the use of the A6 by everyone but those with Z06's, GT3's, etc. So, get yourself a set of Rivals or ZII's in a 205/50/15 or 205/50/16 and have fun.

 

I would listen to this guy. He knows what's up

Although it isn't going to matter next year anyways since Hoosiers will be illegal in the new "Street" class. I would buy a set of BFG Rivals and run the road tire stock class for your region till next year.

And saying that this street tire class thing will kill the use of Hoosiers in SCCA Auto-x ignores the very large Street Prepared and Street Modified classes. Even many of the Prepared/Modified cars run Hoosiers because they prefer the "feel" over bias-ply slicks.

 

I hope you meant 16x6.5" Charlie... A 7" wheel in HS is a no-no and would put you in STF.

 

Ummm... Everyone in Street Prepared and Street Modified can still run their A6's, R1S, V710, Z214, or whatever.

 

Sorry this made it sound like you were implying that the only people using the A6 after the new street class re-org will be those still running the "Super Stock R-comp" class or whatever that thing is going to be called. Whatever. Not important for the discussion here.

 

Before you make an investment on tires and perhaps wheels,

check with your local SCCA on what is legal in Stock classes for this year and for next year.

A base Cooper running in H stock class is OK for this year in some regions but nationally H stock is being merged with G-stock. The requirements for wheel sizes are also being changed for stock classes. A base cooper can run 15x6.5" or 16x7" wheels, not just the OEM sizes. Stock class cars will be limited to street tires with treadwear rating of at least 160 for this year and 200 for next year.

BF Goodrich Rival tires are 200 treadwear rated so they would be a good choice for the future.

Having the widest tire on your base cooper is not always the best option, you may gain some weight and if you are running minimal front negative camber you may not be able to make full use of the tire in any case.

205/50-15 and 225/45-15 are usually a good place to start your search.
Smaller tire diameter allows for lowered gearing which is helpful for more rapid acceleration. A wide tire like 225/50-15 is too tall.

 

My 2 cents and this is not necessarily within the rules but has more to do with what the car can handle within its design. I have a set of Toyo 225-45x17 tires for the track on Enkies with a 38 mm offset and the outside edge of the tire rubs on the inside of the rear wheel well liner. On the front there is less than a half in clearance between the wheel and the strut. A 45mm offset wheel (which I believe is allowed by the rules) will bring the wheel in by about 3/8" which means it will be close to rubbing on the strut. The strut issue will be the same for other diameter wheels. My point is that things are tight in there and be cautious when buying wheels and tires for these cars. The Rival comes in a nice looking 225 that is tempting. Just make sure it fits.

 

bumping this..

i've been planning to run a 225/45-16 on a 16x7 wheel, but the more I think about it, the more it seems like 225 is just too wide for a 7" width wheel... thoughts? i may just run the 205/50-16 like i did for the stock 16x6.5 wheels when i had them.

 

Kyoo,
that is what I am running but only on 17" wheels - see my post above. Just be careful of the offset. My next try will be with 43 mm offset. But I should also note that the Toyo R888s are really wide for their size.

 

225s have been working or me on 15x6.5" wheels. Though Andy Hollis thinks a narrower tire would do better on a wheel that size. Its on my list of things to test to see if a narrower tire is better, I'm not convinced.

The spec for the Rival's I'm using say they can be used on a rim widths of 7" and up. So even the manufacturer thinks they're a bit stretched. But Dunlop's spec for the 225/45-16 ZII is 7" rims and up. That's the other size I'm going to be testing.

If you did want to go to 205, I'd use 205/45-16. (Which is what I did use last year.)

 

Yeah I determined earlier in the year that it would fit, esp for a 16" wheel, but now I'm more wondering if the marginal return becomes negative at a 225 width tire

Yeah his test is kind of what I was referring to - basic rule of thumb states that that's about right. Just wondering if 225 actually ends up losing mechanical grip from being too wide, esp for a Justa (with more rolling resistance, sidewall flex etc)

 

For tire sizes-

205/45-16 fits 6.5-7.5" rims, perfect for 7", 23.4" tire diam.
215/40-16 fits 7-8.5" rims, perfect for 7.5", 22.7" tire diam.
215/45-16 fits 7-8" rims, perfect for 7", 23.6" tire diam.
225/45-16 fits 7-8.5" rims, perfect for 7.5", 23.9" tire diam.
225/50-16 fits 6-8" rims, perfect for 7", 24.9" tire diam.

Tire selection varies with each size. Anytime you can get a perfect fit width you will be using the tire as the designers had intended.

Often times we pick a tire we think will be best for the intended use whether for street or performance driving, then we look for a size that will fit our wheels.

If you are not competing at the highest levels for performance driving then I would expect that being slightly out of a perfect rim fit is not a big deal. There are many other factors that are also important such as tire pressure, alignment, suspension upgrades and adjustments, course surface and design, and driving style.

225/45-16 is a bit wide for a 16x7" wheel but it would be fine. Realize that when trying to make best use of "ALL" of the tire you may have to reduce air pressure to the point where you don't feel handling is as responsive as running with higher pressures. You allow the tire to rollover and make contact with more of the road/course so that you heat up the tire surface more evenly and get more traction.

205/45-16 and 215/45-16 are also good tire sizes for a 16x7" wheel.

 

gotcha. yea general consensus seems to be 205 is the way to go

 

Why not the 215-45? That is also "perfect" for the 7" wide rim. Just curious about your thoughts on this.

 

sadly tire selection is poor for that size

 

It's limited but not entirely bad (depends on what you want to use it for)-
http://www.tirerack.com/tires/TireSe...45&diameter=16
Shows Kumho Ecsta XS (Extreme Summer tire)
$110 each, 180 treadwear, can be used on the street but may wear fast.

In addition, available in 215/45-16:

Falken Azenis RT-615K A competition streetable tire, Treadwear 200.
This tire benefits from an initial heat cycling to make the rubber compound more durable.

 

i think i'd rather have a z2 in 205s - car is being prepped to be "competitive" - theoretically for nationals, but we'll see how things go.

 

LOL. Right you are Anthony - they are Mark Chiles old Panasports and they are indeed 16x6.5.

Kind regards,

Charlie

 

Then I think you'll have to buy two sets of wheels and sign up for a test n tune somewhere. Do you have data acquisition?

It's hard to say whether the tire more appropriately sized for the wheel will be faster. We currently run a 235 on a 7.5" wheel but next year will have some custom 8" wheels. Doesn't seem to be any problem running the 235 on a 7.5" so doesn't seem like a 225 on a 7" would be too bad. The mini is also a lighter car so the tires have less forces acting on them to deform them. If it were me I think i'd go for the 225s and drive around the "squishy" feeling. The car is already "squishy" in street class so driving around the tires isn't a big deal.

 

i'm getting the solo storm app, and the first test n tune in my area is at the end of march. buying two sets would be the hard part of this lol