I'm building an Austin Healey V8, and am redoing all of the suspension, changing to coilovers front and rear. Does anyone have experience on choosing damping rates (based on weight/spring rate?) and suggestions for brands? I'm assuming I will want double adjustable damping.

Thanks

What is the purpose of the vehicle? Street, race, show?

I assume you mean spring's when you refer to dampening rates.. If so..

On a stock car, I would figure out weight ratio of front to back stock and then with the v8, Then I would compare overall increased ratios. and multiply the stock spring rates by that...

Good luck

Car is being built for the street, but my question was more general: How does one go about specifying damping rates for given spring rates, weight of car, etc?

Can't believe I'm the first with this:

Yes, I would check with the street rod guys and the Cobra kit car manufactures. Many of the chassis's used and built by these guys use coil overs. I would say a Big Healey would use the same rate as a Cobra kit. I don't blame you for wanting to ditch the lever action shocks. Specially with a V8.

OK, Spill it. What Healey; year and model, and what V8?





I'm building a 59 Bugeye with a 1300 Suzuki Swift Twin cam and a Samurai 5 sp for Sandy "Shealey"

And I have a 1954 100-4 I will be building with a Rover V8. "Bad dog"

springs are just that... they have spring rates.
dampening is a function of the damper... also known as a shcok absorber

i think he wants to choose damping parameters (rebound etc) for his shocks for a given set of spring rates.

Thats kinda what I figured.. but I know squat about dampening rates..

So I told him a little bout spring rate instead

There are formulas, and some of the better coilover suppliers like Carrera can help you. You'll need to know the compressed and extended lengths (stroke), the approximate weight of that corner, and the angle between the top and bottom mounts. If it's absolutely vertical, hot rod style, that's all you need to know, but if there's an angle from the top to bottom mount then there's some leverage that increases the spring and dampening rates. You can probably find a formula on the net, but it would be better to just talk to Carrera. They're helpful and they'll give you better advice than you'll be able to work out by yourself.

Thanks,

I planned on calling the mfrs for info. I would have liked to have better info, but this is a bit of a dark art. I added one ugly pic, I don't have much at home, but I can add more if there is interest. Engine is a 289 ford, will be mounted with a front plate, a midplate and a rear trans mount. Car will look stock, no flares or other crazy stuff. It is a 1960 BN7 which a nice 2 seat version of the 3000. Frame is being built up now and then it will be blasted and painted before final ass'y. Car was converted to V8 a long time ago in Cali, I bought it 5 yrs ago on the east coast.

EFI,

I think all the lower end adjustable dampers have a wide enough range in adjustment they'll take a pretty big range of spring rates.
Of course, the high end stuff is probably more "tailored" to the spring rate - Koni, Ohlins, Penski. If you're dropping that kind of coin I'd talk to a dealer directly.

On the mid-price there's Spax and AVO, but harder to find a US dealer for?

In the "more affodrable" catagory - your basic (Chassisworks) Varishock, Aldan and QA1.
My research on these (YMMV) - QA1 quality wend down when production went offshore and advancement stopped. Problems with leaking, quickly worn mounting bushings and inconsistent valving settings from shock to shock. I've read Carrera was bought out by QA1, not sure if they still carry the Carrera as an independent line or not?
Aldans - Don't believe they dyno their shocks, heard some good and some bad about them??
Varishock - this is the state of the art/advanced version from the original designer of the QA1. Heard 99% good news about these, all shocks dyno-ed, very high quality build, all USA made. I'm using these on my custom tube-chassis buggy build. They seem to be the best option in this price-range category.
If I had the money I'd probably get Koni's, but at last check the double adjustables were around $400 per, without springs. Single adjustable Aluminum body (rebound adj. only) were around $300? ea.

Several other lesser known "roundy-round" shocks available too, don't think most of these are quite as "universal" as the brands mentioned above. Mostly fixed dampening, but user re-valvable?

At least there are plenty of options!
Jeff

Jeff,

Thanks very much!