Square vs staggered

[qoncept]

Originally Posted by xphiledan

Wider tires will make it feel less responsive. I really don't understand why everyone is obsessed with upsizing the wheels and mounting wide tires. Whole purpose of this car is to make it fun, lightweight, tossible. Mounting wide tires & especially staggered setup is going to lose that fun tail happy nature of the car. Car doesn't make that much power. Don't ruin it w the wrong setup.

The "purpose" of a car is such a nonsense argument. The "purpose" of this car was to sell as many as possible at as high a profit as possible. What the engineers had in mind is debatable. But what I bought my car to do - what its purpose is NOW - is up to me.

I really don't understand why people upgrade their wheels and tires and don't put as much rubber on the ground as possible. Turning faster is more fun. But to each their own. I'm certainly not going to tell someone their car isn't fulfilling it's "purpose."

[ame="http://www.youtube.com/watch?v=yJJA6WRpvlg"]The Jerk (8/10) Movie CLIP - Navin's Special Purpose (1979) HD - YouTube[/ame]

[7thgear]

Originally Posted by BlaineWasHere

My car is an AutoX car. Grip is king. Top speed and rolling resistance don't matter to me at all. What makes you slower is when you up-size the diameter, not width. Plus to my knowledge CSG has not run 255s ever. Actually according to the build I just checked they've not run ANYTHING wider than 225 so how would they even know if wider was faster?

Mike only lists a bunch of 225 tires:

http://www.ft86club.com/forums/showp...0&postcount=27

I really don't see how less grip makes a momentum car faster around any track, but whatever. How much experience do you personally have with different widths???? I know from MY PERSONAL experience my car was faster after the move up from 245 to 255.

what class are you in and what rim are you running

street tires, limited by wheel diameter, do not benefit from going wider.

A6s on the other hand...

[BlaineWasHere]

Originally Posted by 7thgear

what class are you in and what rim are you running

street tires, limited by wheel diameter, do not benefit from going wider.

A6s on the other hand...

I'm not running rims. I do however have 17x9s with ZIIs mounted currently.

[TrogDor the Burninator]

Having been to only one AutoX on my new setup of 18x9 +45 TE37SLs with 255/35 Direzza ZIIs, I can say the confidence in high speed cornering was huge to me ...

That said - I couldn't offer what is fastest. I'm sure the guys going for gold each lap have better information, and they seem to run 17x9 tires from what I have read ...

My wheels have almost identical weight compared to stock, however the rotational mass distance I haven't calculated. I will say this, my circumference is almost dead on to stock as my aspect ratio on my tire 255/35 matches up with the stock tires. The variance on rotational mass distance seems like it would be a very, very small percentage.

[7thgear]

Originally Posted by BlaineWasHere

I'm not running rims. I do however have 17x9s with ZIIs mounted currently.

so you're in STX?

[BlaineWasHere]

Originally Posted by 7thgear

so you're in STX?

Correct.

[ayau]

Originally Posted by BlaineWasHere

My car is an AutoX car. Grip is king. Top speed and rolling resistance don't matter to me at all. What makes you slower is when you up-size the diameter, not width. Plus to my knowledge CSG has not run 255s ever. Actually according to the build I just checked they've not run ANYTHING wider than 225 so how would they even know if wider was faster?

Mike only lists a bunch of 225 tires:

http://www.ft86club.com/forums/showp...0&postcount=27

I really don't see how less grip makes a momentum car faster around any track, but whatever. How much experience do you personally have with different widths???? I know from MY PERSONAL experience my car was faster after the move up from 245 to 255.

Wider tires aren't always better. YMMV.

http://www.cicenet.net/showthread.php?t=11708
Look at the optimal wheel size section.

I'm sure @CSG Mike has tested 245/255 tires. They just found out that 225 yielded the fastest lap time. It doesn't necessarily produce the most grip, but it produced the fastest lap time, and that's all that matters.

Off the top of my head, I recall Mike saying that a benefit of the wider tires was the ability to run more laps without the tires overheating. The 225 tire was more of a one lap wonder type of tire.

Obviously track and autox cars will have a different setup. You just have to find what's best for you.

[vtmike]

Originally Posted by BlaineWasHere

My car is an AutoX car. Grip is king. Top speed and rolling resistance don't matter to me at all. What makes you slower is when you up-size the diameter, not width. Plus to my knowledge CSG has not run 255s ever. Actually according to the build I just checked they've not run ANYTHING wider than 225 so how would they even know if wider was faster?

Mike only lists a bunch of 225 tires:

http://www.ft86club.com/forums/showp...0&postcount=27

I really don't see how less grip makes a momentum car faster around any track, but whatever. How much experience do you personally have with different widths???? I know from MY PERSONAL experience my car was faster after the move up from 245 to 255.

I think the 225 size was for road courses. I can see how wider would be better for autocross.

It's pretty easy to see why wider isn't necessarily better on a light car on a track with any decent straights. More weight and rolling resistance could slow you down more in the straights than it helps you in the corners.

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[BlaineWasHere]

If be interested to see what Mike has tested on the track!

I think once you're at the full bolt on level (210WHP over stock 175) would help you be faster on wider tires with more resistance. But this is something that's not really been scientifically tested I'd bet.

Obviously once you're at FI power levels wider is always better with power to spare.

[John.Hong]

Originally Posted by xphiledan

there isn't anything functional by going up to 18's. Even if the overall weight is the same when running 18's, your rotational inertia is still increased - you want the concentration of weight closer to the center bore. and you gain nothing by losing that little bit of sidewall.

vehicle dynamics are a bit more complicated than using your 1 finger vs 4 finger concept. the chassis engineers specifically dialed in spring rates, damper compression/rebound, sway bar stiffness to get the vehicle to behave in a specific way. the wheel weight/tire width is all part of this along with caster/toe/camber alignment specs.

The OP didn't state his intentions for the car. If he's looking to shave down lap times, then it's a completely different discussion. If he wants to spend money to "upgrade the car", I'd spend it on other things.

The entire essence of this car was to have a fun to drive <30k sports car that lets you hang the rear out. Fucking around with the staggered setup is going to lose this purpose.

Very true! Hence why I added sayiing there is some "form" involved

Wider width will create grip whilst compromising weight slightly if at all. Sure straight aways matter but I believe the corner is where you make up for the time. For me with 255/35 on 18x9.5, I didn't lose much responsiveness if at all. If anything I gain a lot more controlability through corners and helluva lot more grip. If i have no grip, i could care less how much resposniveness i still have.

[7thgear]

Originally Posted by John.Hong

Very true! Hence why I added sayiing there is some "form" involved

Wider width will create grip whilst compromising weight slightly if at all. Sure straight aways matter but I believe the corner is where you make up for the time. For me with 255/35 on 18x9.5, I didn't lose much responsiveness if at all. If anything I gain a lot more controlability through corners and helluva lot more grip. If i have no grip, i could care less how much resposniveness i still have.

such a wide tire requires a suspension tuned to keep the tire flat, with MacPherson struts at the front this isn't as easy to do, esp if you have a lot of caster dialed in (something RWD cars tend to have)

with a wide tire and a car that rolls, you'll end up using only a portion of your tire during the time for which you got the wide tire in the first place

it's all a system

the higher up the ladder you go the more specific your tuning has got to be.

[qoncept]

Originally Posted by 7thgear

such a wide tire requires a suspension tuned to keep the tire flat, with MacPherson struts at the front this isn't as easy to do, esp if you have a lot of caster dialed in (something RWD cars tend to have)

with a wide tire and a car that rolls, you'll end up using only a portion of your tire during the time for which you got the wide tire in the first place

it's all a system

the higher up the ladder you go the more specific your tuning has got to be.

No, no, no. For autox you're prepping your car to a class that limits what you can do. For me, in stock class, I'm stuck with the stock wheel but any tire. The wider the better, period. Whatever I can fit. Yes, my 245s on a 9 inch wheel would be faster than on my 7 inch wheels, but that is a moot point. What is relevant is they are faster than 225s on a 7 inch wheel.

[7thgear]

Originally Posted by qoncept

No, no, no. For autox you're prepping your car to a class that limits what you can do. For me, in stock class, I'm stuck with the stock wheel but any tire. The wider the better, period. Whatever I can fit. Yes, my 245s on a 9 inch wheel would be faster than on my 7 inch wheels, but that is a moot point. What is relevant is they are faster than 225s on a 7 inch wheel.

derp, derp, derp

STR and STX will allow you to use a wheel up to 9" and a tire up to 255 (or maybe even 265... i might be thinking of STU)

furthermore, if you're currently running in C-Stock, you should be running on A6s, and when it comes to the black crack it has been proven that wider is better, 255 A6 on a 7" ain't no problam.


See, this is the problem with auto-cross discussions. People are too focused on their own class to handle a general discussion on tire choice. OPEN YOUR MIND PEOPLEZ

[CSG Mike]

I've tested 235/245/255 tires as well at this point. Generally 225 is the fastest. However, on courses that have few or very short straights, wider tires are faster. E.g. SoWS is faster on a 255.

I wouldn't be surprised if 255 is generally fastest on an AutoX course.



*edit*

While CSG has not purchased wider tires for me to try, I've used my own 255's on the BRZ before, and I've driven countless other FRS/BRZ with varying setups, and keep notes on the setups and results.

I would never consider anything less than 255 on my s2k (and yes, I almost "pinch" them on my 8.5" rims).