Would this work?

I'm having a bit of trouble finding 17X9.5 and 17X10 with the correct offset for racing purposes.

Any other suggestions?

I'm upgrading to Stoptech 13" front brakes so I can't go 16" and I prefer the lighter 17's over 18's.

This is for racing purposes only.

Could I just go with 17X10's up front and have them stick out a bit?

How about 305's up front as well? That would cure the understeer!!!

 

how would wider front tires cure understeer? you want to turn in easier. get smaller front tires for turning and perhaps change out some of the sway bars..

i dont even know if you can fit 10s in the front, can you??


imho get a size that supports R compound..

 

I don't know if 17x10 will fit in the front. If you are experiencing understeer, running the same size tires front and rear will help or cure the understeer problem. It may make the steering feel heavier depending on how wide you end up going, but it will balance the lateral grip between the front and rear better.

Like Chebesto said, make sure you can easily get the r compound tires in the size you need before making a final decision. If you can fit a 17x10 rim, the tread width you want is probably a 275, which I know are readily available. The 275 on a 10" rim will turn in more crisply and should give the same lateral grip as the 305 would on a 10" rim IMHO.

This is all somewhat dependant on what type of racing you are talking about. Are you talking autocross or actual roadcourse duty?

 

Just autocross. If I were to go with 275 F/R I suppose I could just go with 9" front.

Even with a 9" front and 10" rear, I'm having trouble finding lightweight wheels with the correct offset unless I go with a custom made wheel for $2K.

I guess I'll just have to bite the bullet and spend some green!

 

I'd run the same rim front and rear along with the same tire. If you run a wider rear rim even with the same tire, it might still tend to understeer a bit. Your decision depends on how bad you feel it understeers to begin with, and whether you will be doing any suspension mods.

You could go with Enkei RPF1 in 17x9 with 35mm offset front and rear. Those are very good wheels for the money, I think about $1k for a set. For a relatively cheap, lightweight race wheel, that would be my top choice.

Have you found a wheel in 17x10 that is lightweight with offset that seems like it might work? I doubt you'll find one that will fit in the front, assuming it is possible at all. Chances are you'll have to go with a custom made wheel to get the offset right.

 

Look for a post by raceboy that discusses this same topic.

I think he was using the Enkei wheels mentioned above, and was asking opinions on the size.

My recommendation was to go with a 17x9" F and R, with 265/40 in front and 265/45 in the rear. It might have been one of those sizes all around, can't remember for sure.

I'm currently running 245/40 in front and 245/45 in the back on the stock performance rims, and the larger tires in front seem to have helped with the understeer slightly. I'd still recommend a kit like the S-Tune suspension to really cure the problem though.

-D'oh!

 

Here's the link to raceboy's post. Is was just a couple threads down:

https://my350z.com/forum/showthread....threadid=33500

-D'oh!

 

I have done a bit of searching today. I found

Black Racing N1's 17X9 20 offset
$1090
http://www.wheelspecs.com/specs/wheelmodels/891

Weds TC-05
$1390
http://www.wheelspecs.com/specs/wheelmodels/1069

I don't know anything about either rim but the offsets do look a bit better don't they?

I was also told they were very light but I can't imagine them being lighter than the Enkei's.

I think I'll go with the Kumho Ecsta V700 275/40/17's all around.

What if I get the S tune suspension? Will all this work be thrown out the window or will same size wheels/tires be OK???

 

Your 17x9 +20, compared to my enkei 17x9 +35, according to an offset calculator:
Your new wheel will have the following chracteristics:
The clearance from stut housing to the inside of the wheel will be 15mm MORE
The outside edge of the wheel will EXTEND an extra 15mm


compared to RodH's 19x8 +19 front wheel iforged:
Your new wheel will have the following chracteristics:
The clearance from stut housing to the inside of the wheel will be 14mm LESS
The outside edge of the wheel will EXTEND an extra 12mm

and to my 19x10 +30
Your new wheel will have the following chracteristics:
The clearance from stut housing to the inside of the wheel will be 23mm MORE
The outside edge of the wheel will RETRACT in towards the body by 3mm


If you follow all of that, Compared to Rod's front iforged, they might stick out just a little bit too much to clear the fender in front.

 

If you're doing Stoptech 13's wouldn't you be required to have rims that are at least 18" in size?

 

First, it looks like 9.0" wide wheels in front and 10.5" wheels in the rear are the limit. But, it depends on what class you are running in. Obviously, you aren't running stock classes. Since you probably don't have a stripped car, I would assume you are setting up to run ASP or SM2. In either class you will deal in the same suspension rules. Do you have Track Brembos or non-track brakes? If you have the non-track brakes and don't plan on going in larger, you could actually get 16" wheels. In fact if you could run a set of 16" wheels from a company like Circle Racing, your entire setup will be cheaper. Keep in mind because the short amount of time of runs in autocrossing, bigger brakes are not the better rule. You need brakes that can heat to operating temperature from cold quickly. The extra rotational mass actually hurts you during a run. This is the reason all the Miatas in CSP at nationals run the early brakes. They run 13x9.0-10.0 wheels inside stock bodywork this way. Plus there are additional advantages. You can run a shorter tire on a 16" wheel and lower the center of gravity more. You can run a wider wheel/tire combo since the OD is smaller and the rotational outline is tighter. As an alternative, both classes allow you to modify your fenders for additional tire clearance.

 

I like the idea of 16's. I may go this route, but what would be the best width/offset?? Anyone who knows, I'll bite the bullet and be the guinea pig here. If it works, I may have to sell my brand spankin new stoptechs!! I'm definitely going with coilovers so I can adjust height if needed.

 

in 9" width on front, I would shoot for a range of +30 to +35. Anything over +35 is getting close to the suspension, and over +30 is getting too near the wheelwell.

 

Victoracers and Hoosiers are the only tires I can really see going with in 16". The widest tires in 16" R-Compound looks like 265/45 or 275/45.

Cirlcle racing only makes 16X7, 16X8 and 16X10 so I'll probably go with the 16X10's pictured on the below link.

http://www.circlekarting.com/Merchan...uct_Code=85610

I emailed circle racing, I hope to hear back from them tomorrow with good news.

If the 16's don't work out, I'll be going 17X9 or 9.5.

thanks for the help, I'll keep you guys posted and show some pics when things come together.

 

I know this is off the subject, but I am running Yokahoma race tires 255/40/17 and 275/40/17 on 17x8.5" wheels. How are the S-03s compared to the Victorracers on the street? I need new tires soon and am considering 255 and 265 S03s instead of Toyo RA-1s. I have not run street tires in years and do not have much reference.

 

cbsuper, the Stoptech 13.1 inch kit will fit under most 17 inch wheels, including stock. It's the 14 inch kit that requires an 18 in wheel.

I will be running Yokohama AO32 Soft Compound when my car comes in. 245/45/17 on a 17x8.5 wheel front, 275/40/17 on a 17x9.5 wheel rear. These are R compound tires, so you simply can't get better traction without going to an illegal slick. Standing water can be an issue when tires wear down, but as long as you obey local speed limits in the rain, you ought to be fine. They can be tricky as they don't really squeal when they're getting ready to let go like a normal street tire. One minute they're holding on, the next they're stepping out, not really any audible warning (or very quiet, unlike most street tires wailing away at the limit). But I've gotten used to that characteristic by now. I ran a similar tire set-up on my last car for 18 months, only problems were 2 punctures requiring a plug over the 18 months. Tires didnt go flat, but the nail did have to be pulled, then the tire plugged. They dont last too long, (15K - 25K miles, depending on driving style) but I don't care. I can afford a Z, I can afford new tires once in a while. Why drive a sports car and then handicap it by putting 'normal' street tires on? It's kinda like when the car mags road test a new sports car, then report on the skid pad G's it pulled. Who cares if it only managed a .91 or whatever the case may be? Put some real tires on and then test it!. I tested my Type R with a G Meter installed and I recorded 1.09 G with the R compound tires. Lastly, whatever you do, don't even think about driving in snow. You won't go anywhere, way too much solid rubber in contact with the snow, they lack the 'sipes' that channel water and enable you to go through the snow. So for the 10 days or so out of each year there's snow on the ground, I swap back to stock wheels/tires. The rest of the 350 odd days of the year I have the utmost traction avaliable to me at all times.

 

I generally agree about race tires which is why have three vehicles - all on race compound tires. But, how are S-03s? Can they get even close? Tire tests would suggest that they can, but I would like to here from someone running both.

 

I can tell you from running street and race tires, there is no comparison. Unless you are specifically trying to run street tires in a Street Tire class, you are at a bad disadvantage. Right now, I am driving my autocrosser on the street with a set of Yokohama A032R's. These are probably they least grippy of all the R-compound tires, but both the grip and turn-in are a lot better than my street G-Force T/As. On the other hand, the A032's are also very darty on the highway and aren't much fun driving to the event on. Keep also in mind what happens if you flat-spot or cord the outside of one of your street tires autocrossing. You don't have another set to drive on while they are being replaced.

 

SO3's are not even close to R-compound. I have them on my Z right now for daily driving and I've ran a few autocrosses with them. My times improve at least 1 full second with R compound.

 

I ended going with the 82 series Circle Racing wheels for around $850 in a 16X9.5.


I'll have them in hand hopefully the end of next week for the July 13 race!!!

Hopefully I'l have coilovers, sway bars, traction rods and camber kit by then as well. I'm going BSP so I'll need to check the rules before ordering parts.

I have the stock performance brakes and I'll probably be selling the Stoptech kit if all works well.

The wheels are going to be custom made so what offset would be optimal for front/rear??? I assume the fronts should be 28 or so and the rears maybe 20???