I would like to try the combination that Amuse uses on their car (255/40/17 REO1s and 17x9J +40 CE28Ns). I am also considering adopting their spring setup (12k and 14k respectively).

I have done a search on this topic and a couple of threads came up, but nothing conclusive. It does appear though that if a tuner/racing team uses a staggered setup (205(f) and 225

 

also waiting for the answer

 

I'm going to go out on a limb and say hell no....not with 255....I run a 40mm up front on 7.5 and I very rarely rub with 225. WIth a 255 I'd rub like crazy and stick out really far. You need to run wider fender if you're going to run 255's on a 40 offset...

 

I think the rear offset is 63 - they are on my ce28n's - and I would guess the fronts are the same or close to it. Check out pages 50-54 of the 12/2003 Honda Tuning magazine and you'll see the rolled front fenders on the Amuse car.

 

The basically cut the fender in order to have that offset in the front. I think they have switched over to the 17x9 +63 front and back now. There is no way you should run that set-up for a street car, unless you want to destroy your front fenders.

 

I have a similar setup... 17 x 9 ce28n all 4 corners with 245/45/17 Bridgestone S03 on the front and 255/45/17 on the rear... with Tein RS damper lower 1" ..

I was suprised.... but there was NO rubbing at all... no rubbing issue.... however.. the car feels funny... it's good at tight corners... but feel oversteer all the time at bigger corners...

 

I would imagine you would want the rear more softly sprung when running equal sized tires all around. But who knows, if the wing they are using has any appreciable effects on downforce, then they would have tweaked the suspension to adjust for that.

I'm wondering what the Japanese tuners are doing because it seems all of them use same sized tires all around on the S. They might just have a super stiff front bar, and no rear bar. I have 225 up front and 245 in the back and there is an annoying amount of oversteer.

Either find out exactly what they're doing in terms of springs/shocks, swaybar rates , aero mods , or don't try it. I would stick with a staggered setup.

 

I assume you're running +63mm offsets on the ce28N not the +40mm. I'm not surprised that a +63mm could run a 245 up front. However I would be curious about the clearances between your tire and suspension. With a 9inch +63mm offset it seems like it might be close...

 

Yes... +63 on all 4 ... I donno exactly how close they are ... but i would assume they are very close... however... no rubbing or contact with anything.. even when i turn the wheel to the max ..

the way the car is acting on corners is scaring me though... it feels like is floating.. or i'm driving a boat... doesn't feel safe at all....

does anyone know if adjusting camber...or if there is any other way to correct this?

 

I believe they use +63 all around. With that offset rims are barely covered by the fender. There is probably a rolled/modified fender. I guess there is no suspension clearance issues.

Bigger tires up front should provide more front tire grip, so more braking potential (if the brake bias is adjusted properly) and more turn in/rotation potential (but would lead to way more oversteer than stock, unless adjusted by suspension). Essentially more potential grip if balanced out properly.

Suspension is a complicated thing. There are so many more things that can be tweaked that Amuse could have done which are unknown. There are static factors that affect the overall oversteer characteristics (tire stagger, spring rate, antirollbar spring rate, tire spring rate, tire pressures, tire compounds, tire sidewall stiffness). There are dynamic factors based on suspension travel (alignment (camber, toe), shock valving (compression, fast rebound, slow rebound). There are speed related factors (mechanical grip vs. aero downforce, ratio of aero downforce front to back). And I'm sure there are other more subtle stuff too.

In the end to really get what you want, you need to know the application and tune appropriately for it. Do a google search and you'll find masses of tuning guides. There will be no "ultimate handling setting" that works all the time. If you find one it, it'll be a compromise and not the ultimate performance for a certain task. Then again, how many of us can honestly say we use up more than 90% of a car's potential?