Yet another 'will it rub' thread, sigh

[suicidal2af]

Looking at 18x8, +42 offset. Car is currently stock ride height, coilovers in its future, no more than 1.5" lowering. Any clearance issues?

I know 45 is ideal for 17's, and I was wholly planning on 17x8 wheels, but Enkei RP02-J's have garnered my attention, and weight vs size on them is very attractive.

 

[jtmcinder]

Nope. There will be no clearance problems with an 18x8 +42 wheel ... the wheel will not run on anything.

Of course, most people worry about the tire rubbing, but since you gave us no hints about tire size, we can't address that.

- J "man, I can't wait for the no-search=ban rule to kick in" toby

 

[suicidal2af]

235/40/18, I figured that would be assumed. You know you don't have to be a sarcastic ass, right? I mean, it might seem funny, but it grows old *real* fast. Knowledge isn't a license to assume you're better than other people.

 

[jtmcinder]

Tell me about stuff growing old fast! Another thread about putting on wheels that will make the car slower and handle less well. And in a performance forum, no less. Yee-ha!

235/40/18 on a +45 will probably rub in the rear.

- Jtoby

 

[gsx rated98]

with a 235 tire you do run the chance of rubbing. im droped a little bit more then you will be, im at 1.8 and i run 225s and i have no rub issues. I have basicly the same set up for wheels, though i think im at a 43 offset, and i have 18.5 wheels. But a 235 wheel will push the limits.

 

[suicidal2af]

Tell me about stuff growing old fast! Another thread about putting on wheels that will make the car slower and handle less well. And in a performance forum, no less. Yee-ha!

235/40/18 on a +45 will probably rub in the rear.

- Jtoby

So, let me get this straight. Wheels that weigh 8 pounds less than stock, with tires that weigh 5 pounds less than stock, and have 1.5" wider tread, will make the car slower and handle less well?

News to me.

 

[98RedGs]

:laugh:

Either change your attitude or change the website address you type in to get here.
This is for useful information and suggestions, neither of which apply to your post.

 

[jtmcinder]

So, let me get this straight. Wheels that weigh 8 pounds less than stock, with tires that weigh 5 pounds less than stock, and have 1.5" wider tread, will make the car slower and handle less well?

While I agree that wheels that weigh less than stock are attractive, there is still a problem with 18s: the weight is farther from the center, since the heaviest part of the wheel is far from the center. The total weight of the wheel has an effect on handling (by contributing to the unprung weight), but the moment of the wheel (which depends on where the weight is) has both an effect on handling (by changing the gyroscopic effect) and acceleration & braking. Plus, for the amount of money you spend to get lightweight 18s, you can get much stronger and lighter 16s or 17s.

This is why I have posted many times that only "excuses" to run 18s are these: you have decided to run 285/30/18 tires or you have really huge brakes. Otherwise, from a performance standpoint -- especially when it is performance per $ -- it is better to run 16s or 17s.

- Jtoby

 

[gsx rated98]

definatly agree with JToby, 16s or 17s are much better for performance.

 

[suicidal2af]

While I agree that wheels that weigh less than stock are attractive, there is still a problem with 18s: the weight is farther from the center, since the heaviest part of the wheel is far from the center. The total weight of the wheel has an effect on handling (by contributing to the unprung weight), but the moment of the wheel (which depends on where the weight is) has both an effect on handling (by changing the gyroscopic effect) and acceleration & braking. Plus, for the amount of money you spend to get lightweight 18s, you can get much stronger and lighter 16s or 17s.

This is why I have posted many times that only "excuses" to run 18s are these: you have decided to run 285/30/18 tires or you have really huge brakes. Otherwise, from a performance standpoint -- especially when it is performance per $ -- it is better to run 16s or 17s.

- Jtoby

I'll concede that you're moving the weight outward, but you're also reducing the weight of the tires at the same time, which is lowering the weight at the outer edges of the radius. At the same time, running a thinner sidewall will reduce sidewall flex etc etc, you know the deal.

Could 17's be better? It's a definite possibility. I asked a question, though, based off of the wheels I like and want to get, so I would appreciate if you could keep your sarcastic comments to yourself, jtoby. After all, isn't flaming against the rules, like the search thing you brought up?

 

[jtmcinder]

I'm sorry, but I get really bitchy under two conditions: when cosmetic issues come up in a performance forum and when an issue that we've dealt with in detail comes up again. Both of these *seemed* to be the case here, so I lost it. When your 1yo has pink eye and your 5yo is acting like a 2yo and your spouse is out-of-town, this can happen.

Starting from scratch, my basic suggestion is that everyone start out with 245/45/16 on an 8"- or 8.5"-wide wheel with an offset very close to +38mm. (You will have to roll the rear fender lip on a lowered car, but it won't hit the rear knuckle.) We can then adjust the suggestion based on some specifics. For example: if you have big brakes, switch to 245/40/17. But I really see no reason to run a high-moment combination like 235/40/18 unless you have huge brakes. Yes, there's less tire, but for $X, you can get a 16" or 17" tire & wheel combination that weighs less, has a lower moment, and provides more lateral grip than what you can get for the same $X in 18".

- Jtoby

ps. I'm not "above" cosmetic issues; my street set-up is 245/40/17 partly because I like the look of 17" wheels. But I'm aware that this is costing me performance; my butt dyno tells me that the car accelerates and brakes better on my 245/45/16s, even factoring the difference in rubber compound.

 

[suicidal2af]

I'm sorry, but I get really bitchy under two conditions: when cosmetic issues come up in a performance forum and when an issue that we've dealt with in detail comes up again. Both of these *seemed* to be the case here, so I lost it. When your 1yo has pink eye and your 5yo is acting like a 2yo and your spouse is out-of-town, this can happen.

Starting from scratch, my basic suggestion is that everyone start out with 245/45/16 on an 8"- or 8.5"-wide wheel with an offset very close to +38mm. (You will have to roll the rear fender lip on a lowered car, but it won't hit the rear knuckle.) We can then adjust the suggestion based on some specifics. For example: if you have big brakes, switch to 245/40/17. But I really see no reason to run a high-moment combination like 235/40/18 unless you have huge brakes. Yes, there's less tire, but for $X, you can get a 16" or 17" tire & wheel combination that weighs less, has a lower moment, and provides more lateral grip than what you can get for the same $X in 18".

- Jtoby

ps. I'm not "above" cosmetic issues; my street set-up is 245/40/17 partly because I like the look of 17" wheels. But I'm aware that this is costing me performance; my butt dyno tells me that the car accelerates and brakes better on my 245/45/16s, even factoring the difference in rubber compound.

As far as rotors go, I'm going to be running a TCE kit up front with 13" rotors. I'm not so concerned with the price of the wheels, as long as I'm paying under $400 each. So balancing cost vs performance isn't *much* of an issue. I'm unsure of what I'm going to do with the rear as of yet, but they will probably be upgraded to a larger rotor also (mainly to keep the rotors cooler). Cosmetics are minor issue, nobody wants something that won't look good.

The car's main purpose is going to be Solo I time trials. Quaife LSD is in its future, pending commission checks from work.

 

[Jon Lane]

While I agree that wheels that weigh less than stock are attractive, there is still a problem with 18s: the weight is farther from the center, since the heaviest part of the wheel is far from the center. The total weight of the wheel has an effect on handling (by contributing to the unprung weight), but the moment of the wheel (which depends on where the weight is) has both an effect on handling (by changing the gyroscopic effect) and acceleration & braking. Plus, for the amount of money you spend to get lightweight 18s, you can get much stronger and lighter 16s or 17s.

This is why I have posted many times that only "excuses" to run 18s are these: you have decided to run 285/30/18 tires or you have really huge brakes. Otherwise, from a performance standpoint -- especially when it is performance per $ -- it is better to run 16s or 17s.

- Jtoby

Heck of a civilized and informative reply from a guy just treated like crap. I learn more in this forum about my 2G's little metal and rubber parts than anywhere else I can find. Thanks.

Thanks too to the mod for improving the signal/noise ratio.

You don't generally miss something good till its gone...