Drag Wheel/Tire Combo
 

Recently acquired a NA Miata, previously owned an NB that was primarily circuit racing configuration.

This new to me Miata, will have roughly 600whp (NOT LS OR 1.8 SORRY) drivetrain will not break as easily as stock components.

The main question what tire/wheel combo (offsets and backspacing) can I stuff in the rears of a NA Miata to put the power down? I already converted the rear brakes from 15" sport brakes to smaller base brakes to clear 13" wheels. Looking to go either 8 or 9 wide rears if it clears the fenders. What are the serious people running?

Boosted triple rotor?
This could be cool...
You will need wider wheels than 9 with that power in a light car like the NA.
Tell us about your background?

What is "circuit racing" config relate to.
"Circuit racing" to me means World of Outlaws Super Modified type stuff.
Often on dirt...
Maybe I'm wrong here.

Not a lot of drag racers here.

Assuming DOT drag radials, which are generally taller than road course/ auto-x tires, 225's are about in. For road course, you want really wide wheels. For drag it isn't as important.
So without needing flares, probably a 225/50/15 on 15x8's with a +30 to about +40 offset in rear. Fronts, assuming you want staggered, would be the same wheel but with 205/50/15. 225/50/15 in front will bottom against stuff unless you do some modifying.
Personally, I think you should just bite the bullet and do flares. Then you can put some proper tires on it. Like 15x9.5's all around with 245/50's in back and 225/50's in front.

If not running drag radials, then you'll want to stick with OEM diameter tires. That's 225/45, 245/50, 275/35. Several sticky 245/40's on the market that will fit under and NA fender on 15x9's with a heavy pull I think.

I know of a couple pretty serious dudes running 26" tall tires. But that's a bit of cutting. Probably the way to go though, I agree with E on this one for flares.

This is what a MH 8-23-13 tire on a 7.5" lenso wheel looks like.
Drag tires typically use narrower rims that we would use for street/race tires.
https://cimg0.ibsrv.net/gimg/www.mia...f4f9b0b100.jpg
These are bigger than I need. I see others on this forum running more power, with narrower tires with good success.
Do a search Newaza, patsmx5, drag, 1/4 mile

The car will be powered with my old 13B setup, was making well over 600hp at the wheels the NA was a nice find has a complete jdm FD RX7 drivetrain setup stuffed into it, diff and all. Just in need of some tlc and a cage. My previous NB was setup for handling was the most fun car I've ever owned which caused me to get my FD. Did many hpde and track day events with it. So total 180 on this build.

I love that look you have any more info on the wheel specs? Offset etc

The car will running dedicated drag slicks, not DOT compound need as much traction as humanly possible

No affiliation link with wheel details.
Lenso wheels

So, yeah or nay on flares?
What about partially tubbing the car to make room for taller tires?
Easiest if you just pick a tire size (width and OD) and let us work with that. Algebra and all that.
Just flares can allow width but you'll still be limited on OD unless you hack a significant part of the inner fender away. Most road course/ auto-x builds do simple flares to add width but same OD as OEM.

https://cimg5.ibsrv.net/gimg/www.mia...57d938a37b.jpg

These are hoosier 255/50/16 dr2's mounted on mini cooper wheels of all things LOL... They are basically 10x26 tires. To fit something like this you have to roll the fender lip, beat the wheel wells like a mad dog and I also did a little cutting/welding on the front of the battery box location. This is an nb. I assume na is similar?

Below shows them doing work and tucking inside fender under load.

https://cimg2.ibsrv.net/gimg/www.mia...5cf7e503eb.jpg

An excellent data point and good reason not to take my advice on drag racing setups :P

I'll lurk and learn here..

Going to piggy back on this thread and ask about lower power setups. I am not planning on ever cracking 300 to the wheels (and likely will be sticking in the 250-270 range) with regular miata parts. Looking like my best bets would be either MT ET Drag in 22/8.0-15 or ET Street R in 205/50-15 but I don't know why I would choose one over the other (and which one is least likely to break things). I am switching to rear sport rotors so won't be able to run 13s.

This would just be for fun and test and tunes since the drag strip is 15 minutes from work, so it's easy to trundle over thete friday evenings. Building this car to be a jack of all trades, but 95% street cruiser/back wood roads toy.

X 25,

More of a hijack than piggyback:)
Since your setup is quite different; (little bitty tires and half the power) it's worthy of its own thread.

Ha, wasn't sure if it was quite new thread worthy or not.

Update
 

https://cimg8.ibsrv.net/gimg/www.mia...735b74414.jpeg
Old setup with lots of dirt and dust
https://cimg7.ibsrv.net/gimg/www.mia...fd7ed86e2f.jpg
How the car looked when it was completed roughly 6 years ago
https://cimg6.ibsrv.net/gimg/www.mia...7fbe1d6d6f.jpg
My old FD engine should be able to pump out well over 600whp. Just waiting for the turbo manifold to be made and need to install the roll cage
https://cimg5.ibsrv.net/gimg/www.mia...9c49b8e6d8.jpg

This may be more for you: @x_25

Perfect, thank you.

What kind of torque does a 600 whp Rotory make?

Here's a video of what doesn't fit. Going for similar whp.