the original rims I wanted I can't get since it seems they need an order of 40 rims to start a batch or something... so I saw these new works emotions cr 2p now they make them in 18... I was looking to do the 18x10 but not sure what offset would fit.. I dont mind rolling fenders.... not a bad looking rim, but I'd be going all matt

 

For offset you have to figure out what tire width you want to run and how much camber you will run.

If you want to run ballooned tire with max width like 285 or 295 you will want right around +50 offset with no camber and +45 offset with camber. (rolled fenders front and rear)

If you want to run a squared sidewall 265 you will want right around +42 offset with no camber and around +38 offset with camber. (roll lip under on front fenders only)

If you want to run slightly stretched 255 and flush the wheels out to the fenders a bit more you will want to run right around +35 offset with no camber and +30 offset with camber. (rolled fenders on front and rear)

If you want it hella flush only negative offsets will do and you are on your own making it "fit".

If you aren't sure yet what the final set up will be you can get the +50 and run spacers if you want to flush it out.

 

well thing is, i ordered r888 a couple weeks after i ordered my 18x9.5 which i have sitting in my den front 235-40 rear 268-35.. now since i have a chance to go half a size up, im going to have to sell these to get a tire that fits i was trying to do a squareish setup....

camber in front i may run about -2. how much camber are you saying would be needed?
as for the rear i am not to sure, this isnt going to be a hella flush super lowered car, staying around the 25 inch ride hight range.. will auto x (first ever event was with crappy 7inch tires, missed others because of waiting for new rims that never came), really would like to put the car on the track after a couple more auto x


again thank you blue and anyone else who will respond

 

Yup, by no camber I meant street cars running 0 camber and for camber I meant race car with at least -1.5F and -1R.

It sounds like you want a primarily track set up with some camber, so I would go for a +45 offset if available so you can fit any width tire you want on the wheels (up to 295s) and its really close to stock offset so not much scrub radius.

If you keep the 265/35-18 R888 and sell the 235/40-18 you could have a nice square set up on 18x10s up to 18x10.5s with +38 to +52 offset.

 

I have a full set of re-11 265/35/18 if you need a set. New, never mounted.

 

Love the re11a's even tho I have limited miles on them.

 

I run re-11 in my car in 285/30/18 on 18x11.5 wheels. The tires are awesome. Best I have had. I don't have wheels to run the 265 anymore, so someone is going to get a deal.

 

Have you seen the math on width to offset for zero scrub radius? Been curious how wide one can go up front and keep zero scrub.

 

No, but you say "keep zero scrub".

If we assume the stock vehicle had zero scrub (or a favorable scrub radius) from the factory you can just use wheel offset as our reference since offset centers the tire.

------------
Example-
If the stock 225/50-16 tire was 25" diameter with 50 offset and my 295/30-18 is 25.1" tall with 45 offset there is going to be less than 5mm change in scrub radius.

-------------

I say less than 5mm (the difference in offset) because the 2.54mm taller tire puts the steering angle of inclination intersection with the contact patch further outboard than on the stock height tire.

But, one would also have to measure where the front axle is in relation to the upper and lower ball joints to see what affect my added camber over stock alignment has on SAI. Not sure on this one- might stay the same since the steering axis is determined by the same outer upper/lower ball joints that determine the camber change.

Also, one would have to know the short arm long arm axis of camber gain (which I believe Mazda also tried to place at the front axle) for the change to SAI with my somewhat lower than stock vehicle.

--------------

Perhaps it would be easiest to measure instead of calculate.

I guess I could glue a BB or pebble in the middle of my tire, rotate it straight down to the garage floor and turn the steering wheel and see what kind of arc is shown on the garage floor.

And find a stock FD and do the same to compare the two.

Actually, to measure I guess I need to line the glued on pebble to my castor angle or castor will scribe an arc?

 

This guy know what he's talking about. I went with 18x11 295 square and it drives nice and doesn't pull side to side even on ventus td's

 

Why would ventus td's make it pull to the side?

 

More grip = more effect from scrub radius and camber thrust.

Ventus TD are about as grippy as you can get...