I would REALLY appreciate any help with a problem of mine.
I'm trying to find some tires that will fit on my stock 13" x 5.5" (I think) mazda rx7 wheels, they are the 4 spoke ones from the first gens.

According to tirerack.com, these were the original sized tires:

185/70-13



I need something that will serve me well in autocross and light drag racing and hold up well to around 400hp and near as much torque. The tires I was lookin at were the Hoosier RS304, Kumho victoracer v700 and ecsta v700.
The sizes on these are as follows:

Hoosier 185/60zr-13, 205/60zr-13, 225/50zr-13
Kumho ecsta v700 215/50vr-13, 235/45vr-13
Victoracer v700 205/60vr-13

Can anybody decipher all the number for me and tell me if any of these will work, or if you have any help?

Thanks a lot.

 

the stock wheel is 185/70R13 on the width you can only go up to 205 so I suggest that you go with the hoosier 205 being that it has a higher speed rating, or go with the victoracer if you want cheaper race tires.

 

I had to wait until someone else posted on this thread.


The only way you are going to get any traction with your blue sky 400hp & tq, on stock rims, is to put dual wheels in the rear.

Anyone spending the money for those #'s, do not run stock wheels.

However, 400 hp and stock tires does make for one hell of a burnout, through 3rd gear at least.

 

if you are using the car for the street, i recommend against dot race tires. for the street, stick with the stock 185 size or 'upgrade' to the 205/60/13 sumitomo tire that tirerack sells. I just purchase a pair of those from tirerack recently.

 

Would the 205's flex at all? Would it be better to use the 195's? Just wondering because of the autocross.

 

I`ll have a go at deciphering the numbers for you!

First, 205, means that the tire is 205 wide.
The second number 60, means that the height of the tire, aka the tire wall, is 60 percent of the width.
The zr code, means that the tire is approved for the speed that equals the zr code, wich do belive is 240 km/h.
13, means that the tire is made for a 13 inch rim, but you knew that, didnt you?

Forget about 225`s and especially 235`s. They are waaay to wide to fit the rim correctly, remember you only have a 5,5 inch wide rim. Mounting a tire thats to wide on the rim, would only make it sag in the middle, cause you excessive tire wear, and it would rub the tire arches.

For the kind of application you are talking about, i would go 13*7 or 15*8 in the rear, with sticky 225 dot marked slicks. They should do just fine!

 

Thanks a lot for the help.

This car has really been a budget build and I can't find any new wheels to fit the damn 4x110 lug pattern to get it out to autocross by next month. For now I'm goin to settle with stock wheels.

It is race only, probably going to be trailer driven.

Thanks again!

 

oh, so you are using it for auto-x. in that case, hooiser 205/60/13s or the victoracers (which will last longer).

If you can find a 205/50/13 that would give you some better gearing for acceleration.

also 205/60/13s have less sidewall then the stock tires so there would be less flex.

 

Largest I've ever been able to fit onto any of my stock 1st gens (none of which were SEs) was 205-60-13. The 205-70-13s are too large in diameter and will rub during sharp turns and when going over rough terrain.

 

So the 205 is the width, the 13 is the diameter of the rim, and the 70 is the tire highth?

Is this how it is broken down? And if so would going with 55 or 60 be similar to changing the ring and pinion as far as increase in acceleration but less top end?

 

got a v8 or something??


my 13b turbo put down 250 to the wheels...i ran the 205 victoracer.
even shifting softly they would spin somewhat.
awsome tire though. I ran mine as all the time tires.
street and track. they wear very well and have better grip than any other DOT tire you will buy and be able to drive down the highway still.


just as a side note..im going to run 225's on my car this summer
and hopefully when i get my new wheels(special order) I will run 225 in front
and 245 in the rear. Victoracers of course!! now thats traction.

 

70 is the tire sidewall height being 70% of the 205 width

 

For an all around tire with good value take a look at the Sumitomo HTR 200 in 205/60-13.
Check Tire Rack's price
Dennis L. Cote

 

I wonder if peejay still recommends 185 70R 13 over 205 60R 13 on stock rims?

 

what seriously hahahahaahhaaaa

 

Yes! My GLC has some 205 60R 13s on it and I could feel them laying under in a corner that my REPU could handle just fine. They look kinda cool, but I'd much rather get some 185 70R 13s.

 

Yes I do. The 5.5" rim does not adequately support the 205/60 sized tire and you end up with MORE sidewall floppiness. Only now, you have a short wide tire instead of a taller narrower tire, so your steering precision goes to **** as well.