Now this might be a stupid question or it might be a great discusion. Today I woke up in one of those thinking days and I asked my self "self why does everyone run 6ULs and not a widder deeper wheel?" like a 15x10 with fender flares. Isn't widder and lower better for track? Am I missing something?
Over the years I've been in this forum I've seen treands. Like everyone ran greddy kits with emanage, now ms with Garrett turbos. Then: starion IC now: eBay IC..etc etc.

 

well for one most of us are to lazy to pull the fenders out and for 2 most of us are satisfied with the size we have it realy is alot of tire for the weight, on our lil miatas.

 

Because we're all clones without a soul.

I bought them because as magma said, I didn't want to pull or flare and they were cheap and lightweight. I'm not too happy about the finish- it pitted and my brake dust ate it away but they are very functional. I probably could've taken better care of the wheels.

 

Show me an affordable, light weight, attractive 15x10" wheel. Then show me an affordable, daily driveable 245 tire to put on it.

Also there is a point at which too much grip will reduce your laptimes. I think emilio has posted time differences based on tire sizes in the m.net huge 6ul thread before.

 

There are lots of people that aren't willing to do what it takes to even fit 15x9 6ULs, so even less would be willing to hack to fit 15x10's. I know I debated the 15x9's and with an NB I wouldn't have had to do much, but in the end went with the 15x8 and 225's. Still happy with the decision.

 

I'm mostly talking about track tho. DD a 15x10 wheel would be pointless but for the track ***** that are in the 300 whp?

 

I have only run 205's on the track because I'm burning up old rubber...but there weren't gross-acceleration traction issues. It will probably be just right with the 9's.

 

You do know that deep dish performance..right? I can tell you really need to read up on the relationship between width and offset.
Have you ever looked at the price of 15x10 wheels? Have you ever looked at the price of a 275-43/15 Hoosier A6 which also happens to be the only 15" tires that are even in production that are wider than 225 and fit on a Miata?

I tell you what, I run 215-40/17 Kumho V710..yes..17" wheels on a Miata on the track/AutoX. Even with that "narrow" tire, I am getting more grip than the Torsen can handle...and that says a lot. At the local autoX (very competetive.. nearly 200cars/event) I am swapping 1st place finishes in SSM with a monster 'Vette..running 315-40/17 Hoosier A6s...what does that tell you?
Also super wide tires on lightweight cars have several down sides..longer tire warm up times and much more aerodynamic drag to name a couple.

I think a 235/245 width is all a Miata needs...even with 350rwhp. I am excluding the 275-35 from this because there isn't even any competition for it...and the lower speed stuff, like autoX the A6 is specifically designed for. My points are really directed toward track discussion. Yeah.. I would love to see a 235-35-16 tire..or even more compounds for 245-35/16.

 

I personally run 15x8 sportmax for street and track because they are CHEAP and reasonably wide.

They also are to me, the best compromise on tire size/price and wheel size/price.

I spent under 1k for an entire NEW wheel set and R-compound set in 225. I'd spend 1.5-2k EASY if I went for a wider tire in R compounds and a wider wheel.

That being said... If i could pull of wider and also keep it reasonably cheap... I'd do it in a second. GRIP rules.

 

Run the widest tire and wheel you need, but no wider. The additional rotating mass beyond what you absolutely need will definately hurt both your acceleration and braking. There is an old racer's rule that eliminating excess rotating mass at a wheel is roughly four times as important as mass in the chassis. This is because you are applying two forces to a wheel and tire. You are carrying its mass forward, just like the rest of the car, and then you are accelerating its rotating mass around a pivot. This additional effort also applies to braking.

The additional mass of larger wheels and tires also taxes the ability of the suspension dampers to keep the contact patch in contact with the road surface, and should be compensated for. (never end a sentence with a preposition) This change in unsprung weight will translate to suspension composure over rougher/less even track surfaces/transitions.

Wider tires don't generate a larger contact patch. That is a function of an interaction between corner weight and tire pressure. You can achieve a larger contact patch by reducing tire pressure, but only until tire deformation begins to diminish your returns.

Example: 500lbs corner weight and 50psi tire pressure equals 10 square inch contact patch. 500lbs. corner weight and 25psi equals 20 square inches of contact patch. 20 square inches is better than 10, but only if your tire doesn't deform enough under lateral loads to offset your gains and cost you traction.

A wider tire will give you a differently shaped contact patch at the same pressure, not a larger one. The trick is to find that optimization point and not exceed it into the land of diminishing returns. Use as much tire and wheel as you need and no more.
Does that make sense or am I explaining it poorly?

 

Alright maybe 10" wide wheels with 275 tires might be a little too much but how about 15x9 or 16x9 and 0-10 offset? Something that will make the car 8-10" wider. A car that is wide its better than a car that is more narrow. I personally run the xxr 16x8 0 offset for the street and if thing go the way they are going with work I will make it a track car by next summer. I'm def not going to keep my xxr as they are too heavy but I love how the car has a wider stance and it makes it handle way better.

 

My concern was more about offset then with I shoulda explain my self a little better

 

I could see some advantage with wider offset at a tight autox where transitional response was very important, but for an actual track I would hypothesize it would create much more drag (what with the tires outside of the fenders and all) and wouldn't have much of an advantage at all.

Plus, the wider the car, the "narrower" the track. Imagine yourself back at the autox scenario, would you rather try to get through the slalom with a 6' wide car or a 6'5" wide one?

 

Wrong. Narrower cars will corner better than wider cars every time, with all other things equal.

The reason we don't run 15x10s is because 1. nobody makes a good cheap set (sportmaxes are not good) and 2. because nobody makes a good cheap tire that fits a 15x10.

There is a reason why most of the serious fast track cars in the country (Matt Andrews, myself, VagaXT, Emilio, bellwilliam, bbundy, etc) all run 15x9 6ULs with 225/45-15 Nitto NT-01s. 225/45-15 is the widest stock diameter size (except for the 275 Hoosiers, but they are $900 a set), so we all run the Nittos, and we use a wheel that's optimal for the size - 15x9.

 

You guys could be really cool like me and have 195's on a 15x8 with 0 offset

 

Wrong? Then why do proffesional drivers have wider cars?

 

That really doesn't make any sense. There is also the fact that many of the "professional" cars have the ability to design their own suspension to work with the wheel and tire combination.

 

Reminds me, what happened to the guy with the "stretched tires, stretched anus" T Shirt sig? I love that shirt. Haven't seen him for a while.

 

That was Newbsauce. I haven't seen him either.

 

I see a lot of lowriders out here run 0 offset with there wire wheels. i also see them in the parts store buying the outer wheel bearings. lol The big change in offset changes the way the wheel bearings are loaded. The wheels on any car have a max and min offset that there designed for.