What (I think) I've learned to date:
For a serious setup without breaking the bank (ie, Advanced Designs, etc), Bilstein and Koni Sports are the hot ticket. Of these, the Koni offers single adjustability and the Bilsteins do not. How important have you found it to be to have adjustability?
The best spring(s) to mate to one the the aforementioned shocks includes BAT, H&R, and GC. Are all GC coilovers? Thru searching here, it seems difficult to nail down the H&R spring rates. BAT's website does not list their spring rates either...has anybody here ever been told the BAT rates?
What are your thoughts regarding coil-over vs. standard mount springs?
Thanks,
Randy
My opinions may differ from others because it is my only car and daily driver (to change in the fall).
I don't care about how the car's stance is, or if it's "slammed, yo". I care for what works. In a heavy, high CG car, I feel that progressive springs work better than linear springs, especially when driven on roads that have potholes, cracks, joints, etc. All GCs have linear springs (and are coilovers that require strut modification.) Additionally, having linear spring rates means that you have to do some sort of tuning to determine what spring rate is the best for your car, whether it be 250 lb/in, 200 lb/in, 450 lb/in etc. That's pricey to get it tuned properly.
I chose H&R because they appear to be the firmest overall and for their reputation. Springs aren't just wound steel -- I prefer to know how the springs have been made and treated, and I prefer the "harsher" ride than what Eibach's progressive springs would have afforded.
I also prefer the adjustability of the Konis. I like being able to temper the rebound dampening that makes driving on NC roads more bearable. I also like to be able to run different rates of dampening in the front and rear depending on the autocross coarse to help me correct the car -- if it's rotating too much, I can turn them down in the rear in addition to messing around with tire pressures. (I generally run 1 click below full firm in front and 1/2 turn from full soft in the rear).
Bilsteins have been reported to be firmer than Konis at full firm. That is your decision altogether, but since people are having trouble even getting them in the first place, what are you going to do if (when?) you ever run into problems down the road? I'm currently working with Koni to get a problem resolved, and that means talking to someone at Koni North America, not a vendor. I just think that you might want to consider that too...
The Grand Master recommends only lightly upgraded springs, with stiff struts and upgraded swaybars.
Pretty good discussion
here. And, one thing I've found is that most makers do not want to reveal the spring rates or spring rate curves or whatever of their "street" springs. If you're buying a linear race spring, you spec it to what you need, but their progressive springs are carefully crafted for certain ride qualities yada yada yada.
If by Grand Master you mean Fred Puhn, then I'll agree with you
How to Make Your Car Handle by Fred Puhn Good read, but a little overboard on the technical stuff. He basically says that sway bars are where it's at. I disagree with Terry Haines on installing an Aussie bar -- if you have sticky tires on the front, you will oversteer. The BAT bar that I use is almost too much. I wish that I had the time to test it vs the standard SE bar and the SVT to see which one would be best for my setup.
Also, Randy and Roger, I would highly recommend reading this book here:
Secrets of Solo Racing by Henry Watts There simply is no other book out there that describes what you need to do for Solo II including what lines to drive, mental attitude and tire pressures. Best $15 that I have spent for autocrossing.
Well, my current plan is to stick with my stock swaybars, but I'm following TH's spring/shock recommendations almost by happenstance. He, and SeicoRacing's track experience, validate my choices.
I'm not changing swaybars until I've had a chance to play with my strut/spring setup and decide what I really need. Next step for me would be an SVT front.
And, by Grand Master I meant TH, but I've read Puhn's book, too, and yes, he would say the same as TH in this case. Of course, his book also has a section about cutting springs. (Hey, it was the 70's.)
I'll have to add the Watts book to my list.
I've played around with the suspensiona a bit and autoxing and I've found that doing the eibach/koni setup helped, but wasn't nearly as beneficial as adding the AUssie Sway bar and reinforced rear subframe. That was a dramatic improvement.
When I switched back to SVT springs from Eibach, I only noticed a change in the cg, handling didn't change much, about the same amount of body roll. I agree with TH on the springs, these aftermarket companies REALLY do increase the spring rates on 'em, stock ones have worked for me fine.
I've only run stock. I replaced my rear bar bushings, but haven't tested them at an event. Car feels much better on the street, from what I can tell.