DustysA4

What number is light, medium(most commonly thought of as "comfortable"), and heavy? Talking A4's of course. Then what is a really, really stiff number that would be insane to use anywhere but the track? Also, what is a loaded spring rate? The guys at HR special springs said that their spring rate numbers wouldn't prove anything to me because they measure a "loaded" spring rate. Can you explain that?

DustysA4

Anybody....Bueller?

DustysA4

I saw some people on the S4 forum throwing around 800, 900, and 1000 pound spring rates. Isn't that huge? Is that a loaded rate too?

Jimmy Pribble

My UrS4 currently wears H&R springs rated:
285 lb. front
330 lb. rear

I would consider these rates comfortable enough, though they are already a bit of a compromise and there are those who think they are too harsh. Also, keep in mind that the UrS4 is a few hundred pounds heavier than the neu S4.

Spring rates like those that you mentioned are approaching silliness on anything other than an all out RACE car, IMHO.

HTH,

DustysA4

Thanks, I was thinking those numbers were pretty large.

eharleq

I run 380/250's and they are just fine w. konis and an aftermarket bar. Loaded is meaningless crap. Springs are tested in a big compressor...UNDER A LOAD.

Much more meaningful is true rate: rates vary dramatically depending on free length, bar size, bumpstop, shock compression, and tire. Anyone in the biz who can't discuss that with you is a poseur and likely a liar.

DustysA4

So, If HR told me the "loaded" spring rate on their ultra performance coilovers are 510(front) and 620(rear), then would they be heavier if they weren't loaded or lighter? In other words, what is just the plain old spring rate? A guestimate is good for me also.

Also, why would someone want to measure a loaded spring rate if it is so worthless? Doesn't there have to be some sort of purpose for it?

J. Daniel

Lots of automotive springs are progressive. That is the rate goes up as the spring compresses. Wire diameter, varying overall spring diameter and varying coil pitch will produce progressive springs. If they are progressive it's tough to quote a rate because it isn't constant. Perhaps when they say loaded they mean the spring rate at the static (loaded) ride height??

DustysA4

Yeah, I bet that is what they meant. Thanks