A serious wheel question that goes beyond weight and appearance...
 

The most used single description I have heard of for the FR-S and the BRZ is that they are "balanced" in terms of how they drive and handle.

It is common to put wider tires on the rear of a car. This adds a little in the looks depart as well as helps put power down better. With that said, would you want your front and rear wheels to be the same width? How would it effect grip between the front and rear?

http://www.tsw.com/alloy_wheels_interlagos.php
17" dia. widths:
- 7.5"16.85lbs, 8", 9"
18" dia. widths:
- 7.5", 8", 8.5", 9", 9.5", 10.5"
19" dia. widths:
- 8", 8.5", 9", 9.5", 10.5"

I personally prefer 19" wheels since they fill that massive wheel well better.

Kev

If you are going 19" why do you really care that much about handling and balance?

IDK I think 17" and 18" are good. 19's might be too big, but then again, I've never seen the car with them on. Only blinging 20's.

I went with 17x7.5 225 all around because I was concerned I would upset the driving balance and performance of the car with anything larger. That's more important to me then looking good. When more tuner and track data becomes available over the next year, I may change my mind. For others, "its better to look good then feel good" so staggered 18's and dropped would probably be my choice for maximum aesthetics.

Again, what's with all the negativity. Because you don't like it doesn't mean no one else should. Is bashing someone else's opinion all people do on this flippin forum? I guess it is a lot easier to disagree on irrelevant information than it is to actually think about the main focus. It's funny actually because you are now irrelevant to me.


The 19" wheels I was referring to weigh the same or a tap over stock, but are wider. I realize that only the 8" wide wheels have the proper bolt pattern, but the question remains. Stay on topic or go somewhere else.

It is great to hear everyone's unbiased opinions.

Well... he did give you his opinion, which is: 19 will upset the performance. No need to go all berserk on a guy.

If the same wheel can achieve a lower weight in a smaller size, the only reason you'd go bigger is for looks and nothing else (for this car anyways). I'm debating as to whether get the 17 OZ alleggerita or the 18, there's a massive difference in weight there but 18 looks better. Hence the age old question.

Keep in mind that it will also depend on the size and weight of the tires you put on it.

19's
http://www.rayswheels.co.jp/wp/wp-co.../05/86rand.jpg
(from this thread)
http://www.ft86club.com/forums/showthread.php?t=9394

You asked for opinions and he gave you his. It's no more "right" than anyone elses. Wheels are a very subjective choice as is suspension tuning as it should match the driver's preferences and style.

These cars don't really have power to put down, a FWD Camry has more power to put down in a less effective driveline with 215 width tires. I'm not saying wider can't be better just that you don't need it to put the power down really.

Anyways, I don't like staggered setup and the word from RavSpec was that even the JDM guys aren't going staggered. Fast S2K guys often go from the OEM staggered setup to non-staggered.

If you are doing it for looks fine, but if you are doing it for handling, I wouldn't suggest it.

I also wouldn't suggest 19s, for looks, ride quality and performance reasons.

There is a difference between a well stated perspective with sound reasoning behind it (like yours - Dave-ROR) and a comment that doesn't try to help (like #87's). I never said his was wrong. I only stated that it had nothing to do with what I asked, so for him to bring up something irrelevant to talk down on isn't exactly good either. I do admit to going a bit further than that, but that is the biggest thing I see on this forum whenever wheels are general topic.

You clearly stated the sound reasoning I mentioned. Thank you for that. The fact that you mentioned the S2K non-staggered move is a pretty big message.

The stock wheels are 17x7. How much of a difference would 18x8 or 18x8.5 make?

Kev

I run 17x8s with 235/40/17s which made a huge difference.

Whether or not 18x8s with 235/35/18s would be better or not would depend on multiple factors. I'd guess the difference in performance would be marginal either way with an increase in harshness with the 18s.

Your thread subject line is flawed and you're contradicting it in your posts.

That being said, wheels are the jewelry of a car and each person will pick something different. Toss on those 19's and have fun! I can guarantee you there will be very few dedicated track cars running 19" wheels and they will definitely be non-staggered.

19's will force you to have virtually no sidewall to keep the overall diameter even close to stock.

The ride will suffer.

I did say that I prefer the look of the 19" wheels, but that's not what I asked about. I asked nothing about ride comfort or what you think looks best. If it settles the question that isn't being asked, I will most likely go with 18" wheels to keep the performance characteristics. I just said that I prefer the look of 19"s. The question at hand regards wheel width.

"...would you want your front and rear wheels to be the same width? How would it effect grip between the front and rear?"

Wider rear wheels and tires will produce more understeer.

Unless you are tracking the car it's not really a concern.

Going to a wider rear tire on these things will result in more understeer.

The reason for a staggered setup has more to do with balance and temperature management than grip. If you are on a track and are trying to put a lot of power down on corner exit then a wider rear tire might work better because it has more rubber and can handle more heat and load. To go into it further would get pretty complicated. For the most part I like a square setup, even on a car with more power like a Z or a turbo S2k.

And it could be worse. I know a guy who put wider rear tires on the back of his accord.

Wider rear wheels are used to help the engine put down power out of turns. Considering that our cars only make 151tq, there really isn't a need for larger rear tires. Going with a square setup will help keep the grip even front-to-rear. Going to a staggered setup will encourage understeer.

I would think that going from a neutral non staggered car to a staggered would make the biggest difference in upsetting the balance. In a staggered I would think you would be setting up a neutral car to have more understear due to more tracking in the bak and less in the front? Am I wrong thinking this way?

Now if the car was built to be neutral in the staggered format but then to go an put an unstaggered wheel set up, I would think you would end up with oversteer.

Just imagine putting a pair of spare tires on the front or back of the car. I know that is drastic staggering, but do you see my point?

It is really cool readings everyone's explanation. I never would have really thought of oversteer and understeer being so related to width. Thanks guys.

Now if you chose much wider tires (on a square setup) than stock in both the front and rear, would this create more understeer? or is this directly related to the ratio between the front and rear?

If you put on 'much wider tyres' on a square set you might not get understeer but the balance of the car will be disturbed due to the additional rotating mass of the set up - acceleration will be dulled but braking will probably better enhanced. So you can stop faster from going slower.....:iono:

Remember this is a small sports car we're dealing with. The wheel/tyre combo you choose should be suited to what you want the car for - show car / track work / street etc etc.

My advice would be that if you want to enhance the performance of the car by ONLY swapping out the wheels and tyres is that you keep the changes to a minimum. Look at rotational weight and look at putting on 225 or 235 section tyres. Putting on 19" with 255's......the car will be better served on the show car circuit than as a daily driver or back road / track weapon.

Of course if your plan is to supercharge or turbocharge it to 300 HP, look at wider rubber (as well as brakes, suspension etc) but remember that 19's can be a little precious (delicate) if pushed fast due to the lack of rubber between the rim the pot hole you just ran over. :bonk:

The engineers who designed and built this car knew what they were doing. Improvements are best made incrementally.

:thumbsup:

Wider tires would mean more grip assuming they are good tires. Just remember now it will be harder to get the back wheels to break loose so maybe harder to get the car into a drift. But also realize you will be going faster when the tires break loose. You should learn about the car first with stock tires before you increase your grip and speed.

when someone asks such a simple question i dont think its fair not to mention that most of that huge difference is compound and not size

Tires
 

Exactly!!! Compounds and brands will make a big difference too.

I was assuming he'd pick the same compound/tire regardless of which size he went with, I would. :shrug:

I don't pick a size unless the tire I want is available in it :)

That is great thinking. Looking into what tire before the wheels.

The car was designed around same sized tires front and rear, changing tread contact patch (via different widths) would only upset the balance of the car with the stock suspension. You would have to change the suspension from stock to maximize benefit from such a setup, which would undoubtedly change the balance of the car. Stock suspension is setup very well from the factory...I see no need to mess with it at all until it's time to replace components due to wear.

Compound and taking a tire to it's maximum width wheel it fits is much more important to me for balancing the car than just getting wider tires. Wider tires are no good if the wheels you have aren't wide enough to minimize sidewall flex and keep the tread in shape. It's the main reason I stayed with the stock tire size but went with better tire compound and wider wheels for my track setup... besides the obvious weight component (wider tire sizes add 3-4 lbs at a location which will affect the handling/balance more than slightly overweight wheels). I am also not going for quickest time or driving 100% on the limit 100% of the time [this is my daily driver the bank owns after all!] where wider tires would provide more grip (but still at the expense of poise/balance). I am just wanting the car to be better balanced than stock while having a great time on track. Stock size sticky tires on maximum width wheels balance the car even better at the limit than stock because you can read the tires that little bit better with less 'slop' and you have noticeably more grip available. On the street though, Grippy stock sized tires on maximum width wheels for the size will make it seem more 'understeery' or less prone to kick the rear out but you still have excellent steering feel and response.

For me, maintaining the balance means the wheel/tire combination needs to be lighter than stock and the tires should gain minimal weight (not be more than ~2 lbs heavier than stock weight - because no matter how light the wheels, a heavier tire will mess more with the suspension feel than a lighter one.) The reason I went with Kumho XS's over Hankook RS-3's (besides being very familiar with the RS-3's, having always wanted to try the XS's, and the XS's being $14 cheaper) was they weigh less. Having put my FR-S on track last week, sticky stock sized 215/45-17 XS's on 15.6lb 17x8 Kosei K4R's are definitely better balanced than the car was stock... stickier tire compound, 8" wheel width chosen for the maximum tire stretch recommended, and ~4lbs less weight a corner all add up to something really impressive - impressive poise and control with very high level of grip!

So what you guys are trying to say is this car is in optimal handling mode stock?

is that really hard to believe?

It might be possible to run 19s and have the wheel + tire weight come out near OEM weight if you go for expensive forged rims and the right tires, in which case it should still work well with what the OEM dampers are designed for.

Might suffer from a little more harshness in terms of ride quality though.

For a staggered setup it would seem that wider rears would add understeer, but you could always look at running square-ish rubber on staggered rims although I don't know how that would look.

Jury's out until somebody does some actual testing IMO.

Everyone always mentions upsetting the balance of the car. In my opinion, the balance of any car starts with the owner/driver. From there, you set the balance of the car based on your personal needs. Isn't that what tuning and modification is all about? So in my opinion, upsetting the balance of a car would be when someone other than yourself makes a modification to your car. Or making a modification to your car and not experiencing a satisfactory result. So if you want to put 19 inch wheels on your car and you're satisfied with the result, you're not upsetting the balance of your car. You may be upsetting a fanboy by doing that but who cares. It's your car. And you may not be a race car driver. :iono: