My plan
 

So I'm currently building a 400 whp miata and as of wheel/tire selection I'm not too satisfied. I know the current widest tire I can run is a 225 on a 15x9 (I could do 245 on 16's but the tire selectino is not there) So my plan was to get some 17x9 or 17x9.5 enkei rpf1's with a 245, 255 or maybe 275 tire all around, get a 5 lug spacer/adapter, some fenders and have my traction or at least a little more than a 225 can offer. I nkow this will throw off my speedo, id there any easy way I can compensate for this? Does this sound retarted? lol Either way it will be different and I will have good traction. share your thoughts....:idea:

Stop looking at the actual width and start learning about different tire compounds, that's where you will find your answer.

Last time I checked re-11's, star specs abd rs-3s are the stickiest street tires available. I have 255s on 17x9s on my type-s with 220 whp and I can break traction in 3rd. Believe me I know about the compounds and 225 just won't cut it with 400 whp.

FWD :ne: RWD

So are you guys trying to say that 225s are plenty adequate for low to no spinning on a 400 rwd car? If that's the case why don't vettes get that from the factory?

because they make the power alot faster.

and if you sold a car with r specs, the drivers would be pissed when they brought their car in for its first service where they needed to spend another 1500$ in tire.

They also weigh 1.5x what our cars do. you can run the A6 in 275 35 15 its dot, a soft compound and can be purchased in rain tread.

Yea....id like to get more than a 1000 miles out of a set of tires. So no one seriously thinks "my plan" is a decent idea?

no, buy a bigger car.

It's not width that makes you get traction, it's height. FYI

Exactly...and I will have a taller tire.:idea:

You could also consider how the torque comes on in your car, and try to optimize that so that it is more easily controllable in the first place. A flattish torque curve with a declining slope with RPMs provides passive traction control FWIW. You could also think about tunable TC. Cars with very drivable natures frequently outperform somewhat higher dynoing cars with lesser drivability / throttle response.

Also might want to search around and see what others with 400+ whp are using.

Then why where you talking about width in your first post? I run a 205 tire on a 7" wide wheel with limited traction issues over 400 whp.

Fenders, spacers, and 17" wheels are not worth the extra $$$ for limited width advantage.
With the weight disadvantage, you might as well make it a 350hp engine anyways.

Either:
A. Settle for low mileage on R-comps or,
B. Learn to control your right foot with street tires

If you can get into suspension part changes and altered pickup points, then you can adjust things like antisquat such that the rear briefly but usefully pushes down more on throttle down. Ala live axled muscle cars. When the Miata was designed the suspension did not need to accommodate high torque. It's a design issue too, not just rubber.

Good info....I might just do because it no one else has.:fawk:

because I'd like to stay as close to a 23" tire as possible.

I'd stay away from a 23" rim, 22" rims are where it's at.

http://i442.photobucket.com/albums/q...neill/rims.jpg

lol I meant 23" tire

Another factor in the Corvette vs Miata equation is wheelbase. Longer = better when talking traction when applying high horsepower.

Moving to 17's + wider (and therefore taller) rubber is going to lead toward intruding on the fenders. They can be rolled, but really shouldn't be cut due to the welded seam there.

I don't know of any race comp tires in 245-16, however Toyo T1Rs can be had in 245/35-16. They turn 913 revs per mile vice the 914 miles a 195/50-15 (stock) tire from a late-NA.

Which leads to asking, what year car are you building? Seeing how you reference a 5-lug spacer/adapter and all...

96. and as far as the fenders I would cut, reweld and add flares.

Ok I will admit I ran 17's on an NA years ago it just looked lame, and the wheels were heavy, it made the car handle like crap. Or like it belonged in CR.net

17x9 rpf1s weigh 15.9 lbs...lighter than most 15s

Do you understand sidewall height=traction, on 17's you're going to be rolling on 35 sidewalls which=zero traction at 400 whp.

225/50/15 will work perfectly, or a 205/50/15 R compound.

You need tire height.

Jtothawhat already answered your question on the last page :facepalm:

He ran his 400+whp car on 15x7 wheels with a 205 tire, limited issues.

One of my best friends daily drives a 420whp E30 on a 205 tire. Same tire that he used to run 7.2 @ 100 and then later ran a 6.9......same tire.

I plan to be at or close to 400whp in the summer. After much reading and reviews, I will stay with my 15x7 wheels and just use a PROPER tire.

I don't understand why you want to go through all the trouble to make those wheels work. They are not needed, plain and simple. Screwing with your fenders is just going to make it look ghetto. You're going to look really stupid when you are spinning everywhere with a dumb look on your face because you can't figure out why.

Lol. My old enkeis were 12.8

6uls are 11.3 lbs in a 15x7, still only 15.7 in 15x9.

My new konigs are 13.4.

All SM wheels (15x7) are 13lbs. TD, K1, etc.

I can only find the 17x7 rpf1s, which are $225, more expensive than anything I've listed by double, except for the 8 and 9" 6uls, which are still $36 cheaper, per wheel.

Your logic makes no sense.

Speaking of proper tires...

Would a 225/50/15 drag radial hook better on a 15x8 or a 15x9?

I don't think in drag racing/straight line applications it really matters on wheel width, I could be wrong. I ran 225/50/15 Drag Radials on 7" wide wheels with zero issues what so ever.

I was thinking that taller sidewalls are so you can get more distortion in the carcass, which would imply that the narrower (to a point) would be better as it's less stiff.

This is pretty ridiculous.... how a 17x9 can be .2 lbs heavier than a 15x9. Makes me wonder why the 6uls arent lighter considered they're made with very similar processes. Also this setup will be superior because it will have the taller tire for traction with a wider tire for grip. The size I most likely will start with will be a 235/45-17. not a 35 sidewall.

Try doing some research of your own. 15x9 6UL's weigh 12.8lbs.

http://949racing.com/15x9-6ul-nickel.aspx

And 235/45/17? Have fun with your donk. You just don't learn.

thats just what was stated here

Maybe traction control would be a better option? Hopefully it would cost less then all the Fab work you are proposing. also depends on how you intend to use the car for Drag? Road Course or auto-x? DD-Street? Cause the wheel offset with adapters may accelerate wheel bearing failure.
But when its all said and done it's your car and you should do whatever makes you happy.

just my $.02

It is a great idea breh. Put on 17x9's and show us dumbasses up at the track. I ran 215/35 or 40 17's for a week because they were given to me...... They were balls assed garbage.

Here is an idea... Go buy a set of 15x9 6ul's with some 235 50 15's in an R comp!
It has more width than a 225!
It has more sidewall than most R comps for the 15's, sitting pretty at 45!
It is still a lightweight package as well!
Then go buy a set of fully adjustable coilovers.. and have an intelligent person dial those in!

Combine that with a good tune and a competent driver.. and you shouldn't have too many issues...aside from it costing you almost 4k...and this is the cheap way out!

Just think of all the money you would save! LMAO You could actually put it toward a
400whp build...you will need it!...or just buy another set of tires...

Coming from someone who's driven R-Comps on the street (me) I can only advise that you don't do this.

They're sticky, but ONLY after you warm them up. For driving around, you'll get more grip from an RS3.

I don't have an issue...the R888's are fine for street... and the nto1's are similar...
The R888's offer the size I specified.
and the BFG sports I have on my 16" Work wheels are a lot less responsive even at 40* ambient temps..
then again I'm not pushing 300hp let alone 400!

Yeah, I drove on the streets with NT01's. I know how they are. I'd rather have had the RS2's on my other car at the time.

If you're not pushing 300hp, then you'll be fine with any decent 225 width tire.

I will be LMAO.. motor build in progress!...
I guess it is all a preferance the rs3 has a tread wear of 140...the R888 is 100.. I dont have any issues with traction! but for the work the op wants to do I feel either tire choice will do.. the R888 is wider and taller..the Rs3 is CHEAP...money wise (never driven on them before).. Either way I say spend the money on the turbo kit, or build instead so he can make the 400Whp mark possible!

Tread wear isn't the issue. I'm talking about the chemical compound of the tread, and what the operating temp is for it. A cold UHP street tire is faster than a cold race tire.

If you're dealing with 400whp you likely want a 225/50/15 drag radial.

I currently have 225/50/15 RS2s on all corners now and they rub a little everywhere. But they work. 225/45/15 would probably be better. When I am under power they rub like mad in the back. Also don't expect to get full lock when on a hard turn because they will bind in the front wheel well or somewhere in there. Not bind and make the car do flips in the air but you just won't be able to make full lock.

CARCASSSSSSSSSSSSSSSS WHAT A FUCKING SICK BAND!!! LISTEN TO THE WICKED GUITAR IN THIS SONGGGG!!!!! Plus the chick singer is pretty hot.



Details on your build?

How about you pay me a fat consulting fee when I put down 11 billion horsepower on thursday, buy some tires, and tell you what works? Or you could just do what has worked for others IN THIS THREAD who have already run over 450+ hp. Hint they did not run 5 lug bullshit.

[QUOTE=Faeflora;698567

Details on your build?

How about you pay me a fat consulting fee when I put down 11 billion horsepower on thursday, buy some tires, and tell you what works? Or you could just do what has worked for others IN THIS THREAD who have already run over 450+ hp. Hint they did not run 5 lug bullshit.[/QUOTE]

Here's the build/car:
http://forum.miata.net/vb/showthread...hlight=journal

I need details on your lsx coil mounting setup. Is that aplate you fabbed?

This one?

Attachment 241312

I didn't fab it. Joe who is a fabricator at Altered Atmospheres (GT-R shop) did it. If you want one send me a PM with your cell and he can hook you up.


That's quite a build. What are you doing to it? Is it tuned? How much powa?

It's not finished...should be done late spring early summer. Motor hasn't even been cranked. Like I said, shooting for a reliable 400 whp if thats possible but we'll see. Everything is approx. rated for 550-600 with the right turbo.