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Discussion Starter · #1 ·
Hey...

I was thinking, If saving weight on wheels is a great thing in lower gears, then POTENTIALLY, could running 8 inch width wheels in the front and 7 inch width wheels on the back be "better" for performance then just 8" front and back?

Let me try to explain my thinking;

What got me thinking was, if a Porshe with a rear engine RWD runs bigger wheels on the back then the front, then maybe the same should be done for the drive wheels on a front engine FWD.

Why not just run 8 inch width all the way around? The engine is accelerating ALL four wheels, and therefore it is not ONLY the energy required to rotationally accelerate the fronts we need to worry about. Therefore, wouldn't a lighter rear wheel have the same effect as lowering the weight of the front wheel?

If the fronts do most of the braking, the turning, they have the weight on them, and they are the power, and the rears have much less of a role, would some performance be had by keeping the rear wheels at a stock 7 inch width to minimize rotational mass, and only raise the width of the fronts?

Just a thought... :shrug:
 

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Not as much as you might think. That is done due to weight transfer and cambering mainly, it doesn't really affect FWD cars that much.
 

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Your idea is more common than you think in seriously tuned FWD cars, especially those running drag races.

Honestly it all depends on what sort of driving you're going to do. If you're driving on the track then I say get the most grip you can afford & fit on your car. Less grip in the back can cause some oversteer in corners. Then again, with the FWD layout, a little oversteer isn't necessarily a bad thing.
 

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^But you can gain that with alignment setups rather than wheel and tire combos. Your best to stay with an equal width, equal offset wheel and tire all around on a FWD car. Use camber, castor and toe to give any driving feedback you might want, such as turn in response and oversteer.
 

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Discussion Starter · #5 ·
That's what I thought. The most benefit would be mainly for drags, who desperately need the traction in the front.

I am into autocrossing. So, would I want to get as much rubber on the road as possible, all the way around the car?
 

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Currently the DSP car uses 275/35/15 fronts and 225/45/15 rears in hoosier A6 compound. Your idea isnt unworthy, porsche analogy notwithstanding. At a certain point more rear tire on a fwd car is just more weight.

For me to run 275s on the rear would have a tire so large and a rear end so light that it would be difficult to get them up to effective temperature. To strike a better balance with the car I went with narrower tires/wheels in the rear. The smaller tires because of less contact patch get up to temperature faster so I have good grip on both ends.

You would have to be running some pretty wide tires to need to go to a stagger like this and in truth, even at the 225/235 mark you can get ideal handling through suspension tuning while still maintaining the ability to rotate tires and for a street driven car thats a BIG thing(the ability to rotate tires).

Gavin
 

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I disagree, I have had lots of cars (street FWD) where they have been set up such that I cant rotate the tyres cos theyre different...no big deal.

it helps tho to have multiple sets of rims to do this, here in a country thats RHD, I burn about 3 LH fronts to every 2 RH fronts, so you need enough rims and tyres to deal with that wear pattern.

The rears I pick purely for the best characteristic on the back, some times there a 10% higher profile, depending on whether the car is independent rear or torsion bar....you can tune the rear handling with the tyres. one car I had with a "dead axle rear" I used to run 10% higher profile with 20 psi less, to neutralise the handling.....worked a treat. it takes some on road tuning to work out what is best.
 

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RWD cars run a staggered setup to keep their tailhappy car in check!!! stupid idea on a FWD unless you are drag racing with slicks on the front, besides rotating tires iisnt an option for you if you run staggered! i see where you are coming from tho its just not practical!
 

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....why not take a trailer wheel off a old airplane and make it a trike. :) j/k


i want 8" all the way around with big tires. :D what the widest i can go with some bfg's on 7" wide rims? (sorry to whore but the guys who know what they are talkin about are postin on this thread soooooo )
 

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Discussion Starter · #11 ·
Yeah, I4, you are running FD's which are 16x8 correct? What is the best offset on an 8" to make it fit nice?
 

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^30-35 offset is best for a flush look if you can get a lot of camber to help you out. Otherwise, run a 38 to 42 offset with a mild drop (shock/spring).

With a 30 offset, it is very possible to stuff a 9" wide wheel in. I've had them on once and didn't rub, so I know for a fact it can be done.
 

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The 5Zigens I bought are stagger, the seller only sell them in stagger set so I was forced to get a pair of 17x7 and a pair 17x8, still debating what tire combo to get and which pair go on the front. They are all 35 offset, I put the 8" on the back once just to see how it fit, the rims is perfectly even with the 1/4 panel, maybe stick out a few mm :D
 

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Pontiac sold the Grand prix with staggered width tires to good effect.

Remember that using static camber strictly to reduce rear traction has several side effects/ draw backs.

In this arena I say listen to Gavin.
 
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