[AP2-2NV]

what i mean is, i've read on some forums and some mags that when they added wheels of a different offset to their car it threw off the balance of the car. doesn't sound like a huge deal, just wondering if anyone has noticed this?

xviper

Changing the offset of the rims will change the "track" width of the vehicle. This will change the designed handling characteristics. A "huge deal" is a matter of perception and what you do with the car.

[AP2-2NV]

with the range of usual wheel upgrades for the s2k, would you guys say this change is for the better or worse? i would assume the actual offset plays a good part on that answer tho.

Jim@tirerack

A lower offset will widen the track of the car and improve the handling. To low of an offset though and the wheel will stick out of the wheel well.

Race Miata

Also, lower offset wheels increase moment arm to lever up suspension compression on cornering. Even if you have same change in offset, difference in front/rear camber curves will change leverage with different amount and therefore throw off handling balance. The effect of weight jacking from front castor is also more pronounced. For street use and mild offset change, you'll most likely not notice it. The forums and mags you read about are possibly very extreme cases. For example with my miata, stock tires are 185 on 5.5" wheel with +45 offset. My race tires were 235 on 9" wheel with +17 offset. The outermost tread sticks out about 2 full inches compare to stock. My suspension was set up for that.

SpitfireS

I have to say I was really happy to see this question asked. After searching for those key-words I didn't really find an answer so I figured it didn't make much of a difference and I didn't bother asking.
There is no such thing as a dumb question, its dumber not to ask.

The wider the track the better the cornering but the easyer the springs get compressed which gives a softer ride, would that compensate for each other?
Most aftermarket wheels I have seen do not come with an offset close the the MY00 OEM wheels, that makes me think the OEM wheels have that offset for a good reason.
Maybe I should just powdercoat my OEM wheels.

spa-zz

Not in our case. We have a double wishbone suspension so the virtual center of rotation is very far from the wheel. A small difference in offset isn't going to amount to much, if anything. Common misconception.

SpitfireS

You are right.

All the little forces get concentrated at point A via the wheel.
Lets take force of 100.
So the force compressing the spring = 100 . x2/x1
(only at 90 degrees, i know, just for argument sake)
Whatever offset you have doesnt change point A.
Therefore no change in force on the spring.

I might not powdercoat my wheels.


I should have known, driving Honda for 15 years now and always telling everybody Honda uses the same type suspension as Formula 1.

Race Miata

No. No. No.

Lower offset wheels don't increase leverage on compressing the suspension when going over a bump. We're talking about compressing the suspension when hard-cornering.

During hard-cornering, you get more load on the outermost tread on the outside tire (unless you have way too much -ve camber which isn't practical). In that case, it doesn't matter where your point A is. All it matters is "camber curve". For those who don't know, camber curve is a plot of -ve camber change on suspension compression. Imagine the wheel/tire rotates towards -ve camber when suspension compresses. The steeper the camber curve, the more "rotation" you get for a give amount of suspension compression. Imagine you have a force to help rotate the wheel/tire in the -ve camber direction, it'll only help compress the suspension further. With the same amount of force, it's easier to rotate the wheel/tire where outermost tread is further away from the centre of rotation because of leverage. This is how lower offset wheel increases leverage to compress the springs on hard-cornering. See the problem is that the suspension is softened only on hard-cornering but not when going over bump. This is exactly opposite of what you want in a street car.

Race Miata

Not what I'm talking about. See my reply to SpitfireS