My4Dr8Ur2Dr

Hey There. I am new to evo's and AWD in general , (i'm hoping to purchase an EVO within the next few months), and was just wondering since i'd seen a few members running wider wheels in the front that the rear...I was just wondering, what are the advantages and/or disadvantages of doing so.
-Thanks

belizelittle39439

iTrader: (4)

Pro:
You will have a wider track -- and therefore will better be able to control the vehicle's inherent understeer.

Con:
You won't be able to rotate tires

Dave2

iTrader: (11)

will it mess up the differential ?

feldguy

iTrader: (4)

As long as the tires are the same size, not *really* I say not really due to the inevitability that it will do some sort of damage over the long haul we call daily driving.

If you do different OFFSETS to allow a wider track, thats not as effective, however it does help reduce understeer. Usually a good rear sway bar and a nice set of coilovers will accomplish much more effective results than messing with the wheels.

I am working on a setup, currently, that will not be a DD, only part time street duty, not much if anything....

I am hoping to run 18x10.5 in the front and 18x9.5 in the rear with a 15 so offset in the front and something flush in the rear, accomplishing the "cyberevo" look to it, with the effective reduction in understeer.

PM me for questions, but seriously...ask some of the Mueller guys for help with suspension and handling, none better.

RaNGVR-4

iTrader: (4)

Same size tire and it wont mess up the diff, it might have a slight difference in rotational distance, but miniscule.

Now, on to explaining why this actually helps with understeer (the rest of you guys arent giving a correct answer):

Running a wider wheel in front flattens the tread area out, putting more rubber in contact with the road. It also puts the sidewalls of the tire at a different angle in the front than the rear, kinda like this:

Front: ____
/ \
Rear: ____ ____
| | or \ /

What this does, is it makes it so the front tires wont move much when initiating a turn giving you a very quick and direct feel. In the rear, the tire will be able to lean over or squirm, giving you more of an oversteer feel, while also giving the rear tires more progressive breakaway.

belizelittle39439

iTrader: (4)

Hmmm...see I thought that wider wheels or spaced wheels simply widen the track. The angle of the how the wheel contacts the ground is still dependent on alignment setup and how the tire sits on the rim will be dependent on the size of the tire vs the size of the rim.

"Flattening" out of the tire only happens when you have a wider rim on a smaller tire...like using a 235/45/17 on a 17 x 10 rim or something because you're stretching the limits of the tire's size. When you use wider tires on an appropriate sized rim--you're simply using wider wheels which gives you a larger contact patch.

Noob4life

Widening the front track effectively decreases your wheel rate. Lower wheel rate = less roll stiffness on that end of the car, which increases grip.

rjdevo9_mr

i've noticed this with my setup

RaNGVR-4

iTrader: (4)

you guys are straight retarded. Using a wider front wheel with the same size tire (The thread title mind you, you guys are off topic) will increase front grip due to exactly what I said.

Increasing front track (NOT the same as running a wider wheel) increases the scrub ratio, which has inherent flaws and can actually decrease overall driving feel and grip if increased too much. if increased a small amount, it will help front grip slightly if your springs up front are too stiff. otherwise, lowering your wheel rate is detrimental to handling..

belizelittle39439

iTrader: (4)

That's cute...he's mad now because no one agrees with him.

Long story short--all you told the guy to do was run wider rims to increase the contact patch, and tried to explain it in too many words. Bigger contact patch simply provides better traction (and bite at turn in).

I could also tell the guy to increase his negative camber, or to widen the front track, or to decrease the roll couple, or to get stiffer springs, or to get a stonger rear sway...hell...I could even mention changing tire pressures! All these things help in determining how the car "handles".

If you're going to try and act smart and insult other people--make sure you know more than you do now.

xtreme5369

iTrader: (12)

Ha

psiJunky

iTrader: (1)

What about wider rear wheels (18x9 front 18x10 rear) can you uses different size tires to offset the with and have the same circumference so it doesn't ruin the drivetrain?

Noob4life

Increasing the scrub radius (it's not a ratio) increasing steering effort whether its in the positive or negative direction. Saying that "increasing it a small amount" is too general, negative and positive scrub affect macpherson and double wishbone cars differently, with different advantages and disadvantages. Too much scrub is going to hurt any setup, but that's true of too much of anything.

Also too general. There is a school of thought that believes in running the lowest spring rate possible to maximize tire compliance with the road surface. Ultimately, spring rate translates to wheel rate. Explain how lowering wheel rate will hurt handling across the board.

RaNGVR-4

iTrader: (4)

One guy says im too specific, one says im too general, lol. forum tuners FTL. Im not mad, its just humerous how people think they know things, or how they misinterpret a thread altogether.

You are exactly correct Noob, I wrote the wrong word (OH NOES!!!1!) and didnt verbalize what too low of a wheel rate is. you are definately right in that you want to run the lowest possible spring rates you can without it hurting and handling characteristics. this is the same principal as running the lowest tire pressure possible without loosing feel and grip. getting all this right (and matching it to the amount of grip you have) makes the car far easier to drive.


mr2006, stop regurgitating exactly what i said, you didnt actually say anything different than me, you just put it in terms that uber 1337 forum tuners might understand.

dicking with the scrub radius, front track, ect is not part of this thread, and probably is a bit over the head of the OP, so stick on topic as to why wider front wheels will increase front grip. you want to bring tire pressure into it? why not bring caster, camber, the "dave point", linear vs progressive dampening, which rebound vs compression dampening rates are best, ect? Oh, because thats not what the OP asked. wierd how that works. If youd like to debate about that, I am all for it, send invites to Paul gerrard, Nils, Robi, DMS mark, ect and start a thread in advanced. well have some fun.

psiJunky

iTrader: (1)

Maybe it's my lack of tech knowledge, but was there an answer in there.... Is it ok to run 18x10 on the front and 18x9 on the rear without causing damage and if so are you supposed to run the same size tire or different sizes tring to match the overall rolling circumference.