Spring rates (Cup cars & track cars?)

[PeteG40]

I can say by experience the harshness of a g on stock springs varies immensely with the brand of damper!
stock damper- very soft
koni yellows - variable but harder
ta technix - hard!

[scotsjohn]

I used to run on Koni Yellows and the lowest setting wasn't bad , but there was a big change in stiffness on the second setting and third was way too hard. I've been told that softer springs respond better to increased rebound rather than increased bump settings,but what price shocks with individual settings?. As for Pinch's 100lb/inch, it seemed very low, but experimenting with my existing AVO's suggests they are not much more at 125 yet I'm finding them prettyharsh.

[Andy]

What rate you running at the rear Hayesey?

[Phil]

I've ran a 325lb 8" rear and damping to match with good effect. It was probably not as stiff as you'd think. A setup I tried for a track day with a 275 6" front, but it being a G40 broke its gearbox the day before, and with a new lsd box fitted that night shattered the driveshafts. I got some good mileage in on the known local roads, felt great to chuck about compared to the lighter rates, although not a daily setup, liveable with. Key is in setting the dampers right.

[Andy]

After reading one of Yoof's books and doing some maths I'm probably going to use something like 325lb fronts and 200lb rear. If it was a track car I'd go much stiffer at the rear, but it'd make the arse end too lively for road use I think. This all depends on whether my latest ARB experiment works though, if it does I'll soften the front rate up. Car's still back at the bodyshop though! :-(

[dub-disaster]

is it lack of anti roll bar up front that has made you go for the 325lb rate Andy makes me think I've gone a bit soft on the front with 225lb they supply 275lb as standard i have a set of these to try aswell. what length have you gone for ?Also out of interest what book was it ?

[polo classic]

Just for comparison, KW uses 50-140 front(ca 225 Ibs/39,47 nm) and 30-200  springs rear (ca180 Ibs is around/31,6 nm)

[Andy]

Thanks for the info Frode, only just seen this.

I thought 50-140 means 50N/mm and 140mm length, and 30-200 is 30N/mm and 200mm long? Can anyone confirm?

If that's right, then the KW fronts are circa 285lb/in and the rears are 170lb/in.

[Andy]

For anyone else following this thread, the KWs use 20-60-80 tender springs.

That means 20N/mm, 60mm ID and 80mm long.

[Phil]

Took me a while to badger KW into telling me spring ratings, then frode goes and posts them on here a couple days later.

Anyway was quite surprised to see the 50n/mm spring up front, but the 20nm tender takes the brute out of the ride, whilst lowering its rating to 14n/mm untill it is fully compressed and on onto the main spring.

Dual rate spring maths is (1/tender) + (1/main) = A. 1/A= Initial rate.

KW seem to use the 20 60 80 on everything though.

I did some digging on golf 1 ratings, google found one set of V1's with a 60-170 front and 50-200 rear, but also a set of V3's with a set of 50-170 and 40-200's.

Food for thought anyway.

[dub-disaster]

Dont mean to drag this back up but I have done a bit more testing I have now run both 200lb and 225lb springs up front with 180lb in the rear I found the 200s too soft to be any good the 225lb where better but still a bit too much roll when hard cornering so ive now switched to 350lb as ive got a trackday coming up. I would say the ride has suffered a little but not as much as I thought it would its liveable with for sure. Still not quite as flat in the corners  with 230lb front springs and a arb but definantly better.
I just wondered if any one had any suggestion of what sort of rates I can run for my trackday I  the back its my first trackday and I dont want to crash the car because the back end is too livley but I dont want shit loads of understeer either I was considering around 275lb or should I go harder ??
The other thing I noticed when going between 225 and 350 was that I could feel the quife working much better in hard tight bends with the softer setup and despite the disconcerting body roll I think I could put down more power. With the 350s I have had the wheels spinning in the same bends when putting full power on not sure if it was both ornust the inside but worth noting. A 225lb spring with an arb would be ideal and something ill look into over the wonter.