s2kdriver80

I'm going to have the CR suspension (coilovers, front/rear antiroll bars, steering rack stiffener) put in next week. My car is an otherwise stock AP1 MY03 with Bridgestone Potenza S-02s on the stock 16 inch wheels. I'm not sure which OEM alignment (US AP1, CR, UK) I should be using for this new setup.

Primarily, I want to A) maximize the quick-reflexed tossability of this car and the ability for quick transitions which make it so fun to drive and B)minimize the understeer (maybe one shouldn't call it understeer in absolute terms, but coming from an AP1 suspension, this will feel relatively more understeery) I'm going to get from the CR suspension.

As you can see from the specs below, the US AP1 and the CR specs are very nearly identical except that the US AP1 has slightly more toe-in in the rear than the CR. How does rear toe affect the handling exactly? The UK specs as you can see, are noticeably more aggressive all around. More negative camber front and rear, more toe-in at the rear, and more positive caster up front. How does caster play a role in handling?


US AP1 alignment

Front
Left/Right Caster: +6.00 / +6.00
Left/Right Camber: -0.50 / -0.50
Left/Right/Total Toe: 0.00 / 0.00 / 0.00

Rear
Left/Right Camber: -1.50 / -1.50
Left/Right/Total Toe: +0.235 / +0.235 / +0.47


CR alignment

Front
Left/Right Caster: +6.00 / +6.00
Left/Right Camber: -0.50 / -0.50
Left/Right/Total Toe: 0.00 / 0.00 / 0.00

Rear
Left/Right Camber: -1.50 / -1.50
Left/Right/Total Toe: +0.215 / +0.215 / +0.43


UK alignment

Front
Left/Right Caster: +6.75 / +6.75
Left/Right Camber: -1.00 / -1.00
Left/Right/Total Toe: 0.00 / 0.00 / 0.00

Rear
Left/Right Camber: -2.00 / -2.00
Left/Right/Total Toe: +0.33 / +0.33 / +0.67

Ks320

Subscribing to the thread. Those specs are definitely useful ... thanks for sharing!

Sorry don't have answers to your questions

Rodney

what are you going to do with the car? if you are just DD, then you can go conservative on alignment, hence stock specs. if you are racing it, then you need something more aggressive. let us know what intended use is, and we can have better suggestions. oh, and i am local, so you may see my cr on neon green ap1's occasionally....

Mr. Francesco

I would run the UK spec.

Rodney

uk spec has too much rear toe in for CR spring rates.

s2kdriver80

Np, I found the US AP1 and the CR specs whlie searching s2ki and for the UK specs, I had to convert from degree-minutes to degree-decimals since the latter seems to be more common for US applications.

Anyway, aren't you running CR suspension on an AP1 or AP2? What alignment are you using?

s2kdriver80

The car will be DD but driven spiritedly. Like I've said in the OP, primarily, I want to A) maximize the quick-reflexed tossability of this car and the ability for quick transitions which make it so fun to drive and B)minimize the understeer (maybe one shouldn't call it understeer in absolute terms, but coming from an AP1 suspension, this will feel relatively more understeery) I'm going to get from the CR suspension.

Basically, I don't want to lose any of the fun I had when I had the OEM stock setup. I'm hoping this upgrade will keep everything as is, just increase the stiffness and the handling limits.

You mean you painted your S2000 neon green? Sorry didn't understand. See you around.

s2kdriver80

Sorry for the ignorance, but I'm not versed in suspension dynamics. How does toe relate with spring rates?

s2kdriver80

The differences between the aforementioned specs basically lies in caster, rear toe, and camber values.

1) How does more positive caster (as in the UK spec) affect handling and feel? And why would one prefer one over the other?

2) How does more rear toe-in (as in the UK spec) affect handling and feel? And why would one prefer one over the other?

3) It seems the UK spec has more negative camber front and rear. Speaking as a layman, more negative camber gives better tire contact patch with the road to the outer wheel when cornering, hence better traction and stability, right? Are there any other tradeoffs with the UK camber settings other than increased tire wear (less tossability/transitionability, etc)?

By knowing the answers to these questions, perhaps I could choose which alignment would fit my handling preference.

Thanks.

Rodney

talking to sidriver on aim....