Weel offset.

[Jimboblofski]

Ello lads,

I have been reading this fourum for a bit now and am obut to embark on the rear suspinsion for our 2004 car.

Has any body looked into wheel offset? I am trying to look into it but I just wondered what were the veiws of other people.

The way I see it, is that i has a big effect on the ratio of travel between the iner most part of the contact patch to the outer most part. ( I think that made sense) If this is correct then I would assume that it would be best to have the difference between the two as small as posible. Therfore this would mean a 0mm offset.

Also has any body produced any carbon rims and centres. What were the results?

any opinions on this subject would be apriciated

[Jimboblofski]

Ello lads,

I have been reading this fourum for a bit now and am obut to embark on the rear suspinsion for our 2004 car.

Has any body looked into wheel offset? I am trying to look into it but I just wondered what were the veiws of other people.

The way I see it, is that i has a big effect on the ratio of travel between the iner most part of the contact patch to the outer most part. ( I think that made sense) If this is correct then I would assume that it would be best to have the difference between the two as small as posible. Therfore this would mean a 0mm offset.

Also has any body produced any carbon rims and centres. What were the results?

any opinions on this subject would be apriciated

[Frank]

We look for the biggest offset 13" wheels you can get

So you can get small scrub raius (20-30mm), zero kingpin incilation, and package the beastly sized aftermarket (wilwood dynalite) calipers we use.

[Scott Wordley]

Plus you want to minimise your track width as much as possible to get through slaloms. Therefore squeeze all you can out of the wheel offsets.

Regards,

Scott Wordley & Roan Lyddy Meaney
Monash FSAE Wingmen
http://www-personal.monash.edu.au/~fsae

[Frank]

didn't see that you said rear..... i thought it said front

well anyhows, i'd say most teams would use identical front and rear rims

Frank

[Will98Cobra]

what advantage is gained with the zero king pin and small scrub radius. Just wondering

Thanks

William Austin
ODU Motorsports
Chassis/Suspension/Controls

[ben]

Positive kingpin inclination (KPI) gives you positive camber change as you steer. There is no reason in the world you would want this.

The only reason people run KPI is to try and reduce the steering offset, doing this reduces steeringkickback. Hence if you can acheive zero KPI with a small offset you have a win-win situation.

Ben

[Bob Wright]

the ratio of outside contact patch travel to inside contact patch trave is down to the instantaneous centre of the upper and lower wishbone and nothing else, forget offset at the rear of the car it doesnt matter, just get your camber change right, you rc and wheelrates doing similar stuff to the front suspension and your toe control right. The best way of getting the front and rear doing the same thing is starting top and bottom outboard picups about the same spacing from the hubline (for front and rear) and then keeping your effective top/bottom wishbone length ratio the same, front and rear. If you do that your half way there and if your chassis is any good your sway bars and dampers will do the rest. Come to think of it, identical front and rear geometries for fsae cars is a good start. they run so close to 50% front elastic roll reistance anyway that the tuning range you need would be well within sway bar range.

Bob Wright
Monash University
Australia

[wacko]

was just wondering wat kinda figures people run for the rears? is KPI, castor, offset all at zero?

[Bob Wright]

kpi and castor dont matter at all at the rear. Just focus on toe, camber, and roll centre control

Bob Wright
Monash University
Australia

[Krlos]

That's assuming that their is no compliance in your suspension which is never the case...

[exFSAE]

Is this a joke?