Poll: Vote for your preferred wheel size

[jdl1pt]

Hello all,

I'm trying to decide what size wheels I should go with for a track/autox/weekend set up and would like the forum's input. Initially I thought I'd run a 19" set up to get a lower profile tire, but the idea of a lighter wheel, cheaper tire, and larger tire selection is tempting. I'm going to try and post a poll for everyone to vote, but would also appreciate it if you could leave comments about why or why not you would go with a particular size. In the future I'll tabulate the pros and cons for each wheel size and post them at the front of this thread. (I realize that width and offset also plays significantly in the selection of the final set up, but for this post I'm more concerned about diameter.)

[jdl1pt]

reserved

[BTM]

Didn't read before I voted...for autox/track 17s

[StigJ]

Originally Posted by BTM

Didn't read before I voted...for autox/track 17s

+1

[tekmoe]

18's for sure

[v3.0si]

what 17's will fit over the front brakes on an ///m? surely it must be SUPER close to hitting the caliper...?

[Beedub]

a nice lightweight 19" for me...... looks and performance :-) My BBK has Huge front rotors....

[Finnegan]

18s for the following reasons:

• Good compromise in stiffer sidewall vs. 19s and 17s
• Better selection of tires (and ability to shop for competitive prices for extreme summer performance between brands, e.g. Hankook, Nitto, and Dunlop, etc.--see Beta's tire thread).
• I'm not sure about this one, but wouldn't a wheel that's tight to the rotor (17) inhibit the cooling capability of the rotor vanes to move air? That might be an issue for the track where managing heat is a big issue (not as much of a concern for AutoX).

[jdl1pt]

Ron, thanks for your feed back. Interesting point about heat disipation with the 17.

[BTM]

Originally Posted by v3.0si

what 17's will fit over the front brakes on an ///m? surely it must be SUPER close to hitting the caliper...?

Both OZ Ultraleggeras and Team Dynamic Pro-Race (both are 17x8 ET40) fit my car no issues.

Edit: pic with the OZs

[BTM]

Originally Posted by Finnegan

[*]I'm not sure about this one, but wouldn't a wheel that's tight to the rotor (17) inhibit the cooling capability of the rotor vanes to move air? That might be an issue for the track where managing heat is a big issue (not as much of a concern for AutoX).[/LIST]

I've always been under the impression that spoke design had much more to do with airflow than diameter...though I understand the logic you're using. AFAIK fluid dynamics makes no logical sense (to me at least) so in reality who knows

[v3.0si]

if you can pick up some 17's under 16 lbs ea you'd be set (as far as rotational intertia goes).

the only thing to consider then would be how much deflection in the sidewall of the tires is tolerable. you could even reduce the overall diameter of the tire to (theoretically) have better acceleration. it'll mess with your cluster a bit, but since it's your track car...

where's HACK at? he knows all about this stuff!

[jdl1pt]

Originally Posted by v3.0si

where's HACK at? he knows all about this stuff!

Where is Hack, I would appreciate his input.

[Finnegan]

I don't know. Haven't seen a post since the 4th--you can always send him a PM.

[cmark8]

If there's no BBK involved, 17" is the way to go. The wheels are lighter, the tires are lighter and MUCH cheaper. IMHO it's the best choice for track.

[Jbs]

I would get 19s if i ever drove it on the street. 18s if i didnt (lots of options).

I would love a set of 18x12 ccw classics though, i'd rock those anywhere.

[The HACK]

For performance purposes, the equation is simple.

Put the grippiest tires with the lightest wheel and tire combination and widest possible setup on the car that will clear the brakes.

However in real life it's NEVER that simple.

To put it another way. If you can not change the grip of the tire (meaning you're using a specific range of compounds) significantly, you will want to put the lightest rims on for best performance. If you can get a set of 20" rims that weigh less than a set of 15" rims? Get the 20" rims because it's lighter.

Unfortunately, if you can make a 20" rim lighter than a 15" rim, you can take that same material and technology and make that same 20" rim design in a 15" rim and it'll again be significantly lighter than the 20" rim. HOWEVER. That 15" rim will not clear the brake rotors and calipers. No way. Typical rule of thumb is, add 4" to the rotor diameter to get the smallest wheels that will fit, and on the MZ4, that means the smallest rim that will fit is an 18" (13.5" + 4" = 17.5") rim. There are certain 17" spoke/barrel design that will barely clear the front brakes.

So the wheel diameter part of the equation? The lightest 18" available. Unless there are some 17" that will clear the brakes that's even lighter than the lightest 18". However, again, once you start throwing other variables in then you'll need to re-evaluate. For example, if that 17" rim does not come in a specific width available for the widest possible compound, i.e. you can't fit 275's in the rear because that 17" rim only comes in 7.5" width? Or if the sticky tires you're getting for free only comes in the 17" size? Or if the class you're running in only permits OEM size rim/tire combo? Those are all factors that will determine what is the "optimum" size wheel and tires you need to use.

For example, I'm not too keen on spending a couple of grand on a set of light weight wheels, but I am keen on running Nitto NT-01 R-Comps at 245F/275R, since I get the rears for free as scrubs from a friend. Luckily at 245 front and 275 rear, they're just barely narrow enough to run on the factory wheel per the tire manufacturer's recommendations. So that's what I use, the factory rim, for track use. Now, if I start working again soon before my severance pay runs out, I might blow the rest of my severance on a set of light weight forged rims, 18"x8.5" front and 18"x9.5" rear to make the tires run on its nominal width rim, or I might just blow that on a set of light weight rims for the WRX so I can run the Hoosiers I got for dirt cheap on it.

[jdl1pt]

Originally Posted by The HACK

For performance purposes, the equation is simple.

Put the grippiest tires with the lightest wheel and tire combination and widest possible setup on the car that will clear the brakes.

However in real life it's NEVER that simple.

To put it another way. If you can not change the grip of the tire (meaning you're using a specific range of compounds) significantly, you will want to put the lightest rims on for best performance. If you can get a set of 20" rims that weigh less than a set of 15" rims? Get the 20" rims because it's lighter.

Unfortunately, if you can make a 20" rim lighter than a 15" rim, you can take that same material and technology and make that same 20" rim design in a 15" rim and it'll again be significantly lighter than the 20" rim. HOWEVER. That 15" rim will not clear the brake rotors and calipers. No way. Typical rule of thumb is, add 4" to the rotor diameter to get the smallest wheels that will fit, and on the MZ4, that means the smallest rim that will fit is an 18" (13.5" + 4" = 17.5") rim. There are certain 17" spoke/barrel design that will barely clear the front brakes.

So the wheel diameter part of the equation? The lightest 18" available. Unless there are some 17" that will clear the brakes that's even lighter than the lightest 18". However, again, once you start throwing other variables in then you'll need to re-evaluate. For example, if that 17" rim does not come in a specific width available for the widest possible compound, i.e. you can't fit 275's in the rear because that 17" rim only comes in 7.5" width? Or if the sticky tires you're getting for free only comes in the 17" size? Or if the class you're running in only permits OEM size rim/tire combo? Those are all factors that will determine what is the "optimum" size wheel and tires you need to use.

For example, I'm not too keen on spending a couple of grand on a set of light weight wheels, but I am keen on running Nitto NT-01 R-Comps at 245F/275R, since I get the rears for free as scrubs from a friend. Luckily at 245 front and 275 rear, they're just barely narrow enough to run on the factory wheel per the tire manufacturer's recommendations. So that's what I use, the factory rim, for track use. Now, if I start working again soon before my severance pay runs out, I might blow the rest of my severance on a set of light weight forged rims, 18"x8.5" front and 18"x9.5" rear to make the tires run on its nominal width rim, or I might just blow that on a set of light weight rims for the WRX so I can run the Hoosiers I got for dirt cheap on it.

So what you are saying is, "it depends." (One of my most favorite phrases.) I appreciate your valuable insight, you're contribution has definitely added different issues that need to be considered. And thanks all who gave their two cents in the form of a reply or PM. I've got a much better sense of the direction I want to go and will update the thread in the next few weeks with a synopsis of the info gleaned from this thread.

[dorifto88]

i say if i only had one set of wheels, 18s. if i could afford a "track" set of wheels, 19's for the street (i suppose) and 18's or 17's, depending on how much you want to spend, sizes and fitment, etc.

good luck John !