Help with complex suspension geometry (long post)

[televascular]

I drive my '06 Si fairly aggressively, so I am looking to improve my suspension. I do not participate in club racing or anything of the sort; nor do I drive at the limits of my car. This is purely for my own self-satisfaction. I have a grasp on theoretical suspension geometry, but no experience when applied to a real-world situation. Feel free to correct me if you find something at fault.

My goal is to improve overall handling, reduce understeer (but not too much), and spend my limited budget as efficiently as possible.

To meet this goal, I have narrowed down my options to the Progress rear swaybar and a front camber kit (plus an alignment). I believe that stiffening the rear bar while simultaneously dialing in a little negative camber up front will get me the results I want. All for under $300.

But upon doing more research prior to finalizing my purchases, I realized that suspension geometry is much more complex than I had thought, especially when lacking real-world data. Please clarify some things for me if you can...

The service manual says the rear wheels have -1° 30' of camber. Does this translate to -1.5°? I am not sure how the "minutes" designation is measured.

Ideally, I would like to adjust my camber settings to be -1.5° in front and -.75° in rear. In my mind, I feel this would be a good compromise between reducing understeer (compared to factory settings) and limiting excessive tire wear. I have read that toe affects wear more than camber so I should not worry, but that doesn't mean camber doesn't affect wear. Perhaps a knowledgeable member could convince me that -2° front/-1° rear is a better setup...

...but regardless, it's a moot point, since I am not willing to spend money on the [over-priced] rear camber kit. Which brings me to my next question: if my rear camber stays at -1° 30' and I adjust my front camber to equal the rear, what sort of effect will it have? I assume it will reduce understeer, but how will it compare to my staggered ideal setup (-1.5° F/-.75° R)?

My questions will gradually become more and more ridiculous.

The negative rear camber allows the tire contact patch to stay an optimal size while cornering, resulting in increased grip and understeer; that much I understand. But the Progress bar is designed to reduce the difference in movement between the left and right suspensions, limiting the amount of camber change while cornering. Does this mean that, with stock negative camber, the Progress bar will prevent the outside rear tire from achieving a flat contact patch during aggressive cornering? Should a stiffer rear swaybar be accompanied by careful re-adjustment of rear camber? Or am I worrying too much?

And finally: I am trying to achieve close-to-neutral steering without actually having neutral steering. I would still like to have some understeer as a safety net, so I can just let off the throttle if I need to regain control. Will the combined rear swaybar + negative front camber result in too much compensation, creating a twitchy, neutral car? I fear I do not have the skill to correct myself in such a scenario.

If you've made it all the way through to this last paragraph, I commend you. You have a lot of patience and, hopefully, willingness to help. Please feel free to [constructively] criticize what I've written; I may change my mind if sufficient evidence can be provided. Also, please do not suggest CAIs or other such modifications. I am not interested in increasing power.

Thanks!

[djsolution]

Wow, that's a lot of questions. For starters, -1 30' does equal -1.5 degrees of camber. Just like in lat/long designation a full degree = 60 minutes. As far as the front to rear camber effect, I know a -2 deg front and -1deg rear is a good setup for autocross due to the rotation you get but I would imagine you sacrifice some tire wear and stability at speed. The rear sway bar is money for any civic period. I had one on my EP3 and it was as noticable a change as putting my mugen sport sus. on. As far as how to adjust camber to accomodate the effects of the sway bar, I have no clue. I had -1.2 degrees camber in the back and it seemed to feel just fine. If you're not looking to autocross or road race then I really think you're worrying a bit too much. For everyday street driving (like you mentioned), a little understeer is good for your health. I'm sure there are plenty of people on here that could give you more technical help though. good luck!