I'm looking down the road a little and suppose I had the the skill of a F1 driver and was looking to make my miata into the fastest Time Attack/Road Race Miata ever. Assuming the car would be built with extensive Aero/downforce/ducting and flared wheel arches to support basically an unlimited tire width(custom rim). At what point would the width of the tire start to slow the car? I assume there are a few variables (power, weight/downforce, more (not really thinking too indepth right now))

I cant even really find a 15" tire with anything larger than 275. I know they make them but aren't common. Like I said this is all completly hypothetical at this point and please don't throw out some BS as I am just curious if anyone has done anything like this.

Would it be worth going to a 16 or 17" rim to have more tire options? and Bigger brakes?

I realize this is all probably overkill and testing will be the only true answer but if there is any true, relevant answers/opinions they would be greatly appreciated.

 

Avon makes a 275/570/R15 Radial Slick, Section width 11.40", Tread width 10.70"

If you manage to get those under your car I would be impressed.

 

I'm guessing that anything you find wider than a 275 in a 16 or 17 inch wheel is going to be considerably taller than what will fit under something that could reasonably be identified as a miata.

 

Are we talking massive HP, corrected suspension geometry, etc...?

In the real world, you would be hard pressed to need more than a 275 on a Miata. The amount of $$ it would take to build a Miata that could really use something bigger would be better spent on a better car.

Last weekend in 90* heat on 275 R6's I couldn't even get them past 150*, and they achieve optimum grip at 190*! This is in a 220whp car with aero (admittedly not the most abusive setup, but it gives you an idea)

 

Check what Hoosier has in inch sizes if you really want bigger 15's

 

If you are planning on making time-attack levels of power (400+whp) there is no tire on the market today that is too wide.

 

I am.....

"Are we talking massive HP, corrected suspension geometry, etc...?"

Yes(500 maybe more eventually), possibily but trying to stay with original geometry with a lower offset rim

"I'm guessing that anything you find wider than a 275 in a 16 or 17 inch wheel is going to be considerably taller than what will fit under something that could reasonably be identified as a miata. "

I wouldn't care as long as it would fit. Would give me more top end.

"Avon makes a 275/570/R15 Radial Slick, Section width 11.40", Tread width 10.70"

Dont think there would be any issues, i would build to fit. I'm really looking for tires with widths ranging from 275-305

 

Hoosier 23.5X11R 16 and 23.5X12R 16 R75 compound radial slicks. Goodyear makes similar sizes as well designed for GT2 class cars of some sort. I have seen them used quite effectively on NC Miatas. They are only ½” bigger overall diameter than really fits on an stock inner rendered NA/NB Miata. It is my intention to build a simi tube framed Miata around this size tire within the next few years. Though at this point I think I plan on sticking with 11” rather than 12” wide and use 16X11” wheels.

Bob

 

275/35/15 DOT Hooser versus 23.5X11R16 Radial Slick Hoosier.

 

I suspect the 23.5x12R16 Hoosier is the widest "stock" diameter tire available.

 

I'm not sure if rules had an impact on their decision, but Sierra Sierra which is a practically unlimited budget team, runs between 250 & 295.

 

At those tire temps I would try A6's. They operate best between 140-150 degrees.

 

Dayum....I do believe that would pull 2G

Any rim options you're familiar with?

 

I was thinking the same thing. Unfortunately I DO have a limited budget and I'm guessing A6's would wear out VERY fast. I think my best bet is just to downsize to 225 R6's until I add another 100whp.

 

Also, at what point/tire size does it start to become difficult without power steering?

 

Boost you are building the wrong motor if you want time attack 5-600+hp.


to do well at time attack you also have to have




good driving skillz

 

You're reaching a little too far into the hypothetical world.

At the point at which you have enough power and chassis to handle 275 r-comps and 400+hp properly on a Miata, you better have a planned fitness regime to keep yourself healthy and strong enough to handle a car without power steering.

 

I wonder how many of these bullshit threads its going to take before he ACTUALLY gets his car up and running and putting down power, much less actually competing with 500+ whp.

Seriously...

This horn tooting is getting so pathetic its just sad.
I have A QUAIFE
I have a 500WHP SETUP
I have FIFTEEN BY TEN RIMZZ
I am PRO F1 DRIVER
I AM BUILDING SERIOUSLY FAST CAR
etc


Just finish it then talk dude
You "overnighted parts from japan", we get that, and power to you for spending the dough, but come on.

 

I was just on 275 R6s all weekend w/o power steering and barely noticed

 

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