240z

[Tom Donnelly]

Ok, how do you detemine spring rates. I bought a pre-built car and the current springs have no markings whatsoever. The fronts are blue and the rears are a chrome color. These actually match what was on my old 240z but its been 10 years since I monkeyed with the springs on that car so I don't remember.

I've been going over katman's posts on suspension setup and looking to work with a baseline on the car, but that's difficult with unknown spring rates.

Are hyperco springs color-coded?

Where's a shop in Atlanta that can test spring rates? Landrums? Robinson Racing?
Thanks,
Tom

[pballance]

Tom,

You might get lucky and have the rates scribed on the top/bottom of the coils themselves. I know on my old hypercoils there was only a tag wrapped around a coil that easily is knocked off. Eibachs are only painted on that I know of. I have started using a cheap vibrating scribe to note the rates on the top and bottom flat part of the coils.

John Williams may be able to point you to someone with a spring rate tester.

Paul

[Tom Donnelly]

Thanks Paul.
I looked at the tops and they're pretty scuffed up and unintelligible. So I'll try the testing route next. As far as springs go, how do hyperco, eibach and landrum compare?

Tom

[Tristan Smith]

Tom, I don't have his number handy, but you can try giving Dick a call at Magna Shock in Chamblee (formerly Carrera shocks) and see if he has a spring tester. just an idea.

[Tom Donnelly]

Tristan,

Thanks, and that's not for from where I work.

By the way, the 300 looks great. What colors are you going to paint? Red White and Blue?

Tom

[kthomas]

Spring Rate, K = (G*WD^4)/(8*Ne*Davg^3),
where G = 11,000,000
WD = wire diameter
Ne = number of effective coils
Davg = average diameter (ID+OD)/2 or OD-WD
You have to take a wag at the number of effective coils, but for most springs that are ground flat on the ends there's about 3/4 coil on either end NOT effective, so count the total number of coils and subtract 1.5.

Or, you could stand on them and divide your weight by how much the spring compresses.......or if you were worried about breaking your ankle with that method just go see Harry Robinson.

[Tom Donnelly]

Spring Rate, K = (G*WD^4)/(8*Ne*Davg^3),
where G = 11,000,000
WD = wire diameter
Ne = number of effective coils
Davg = average diameter (ID+OD)/2 or OD-WD
You have to take a wag at the number of effective coils, but for most springs that are ground flat on the ends there's about 3/4 coil on either end NOT effective, so count the total number of coils and subtract 1.5.

Or, you could stand on them and divide your weight by how much the spring compresses.......or if you were worried about breaking your ankle with that method just go see Harry Robinson.

Keith,

Or, you could just keep scraping the rusty spot until you finally see a number scribed on the spring. Took awhile, but I found it. Now I have to go see Harry anyhow to get that knee bar installed that you and Chet pointed out about 8 years ago.

Glad you're still around.

Thanks,
Tom

[Tristan Smith]

Tristan,

Thanks, and that's not for from where I work.

By the way, the 300 looks great. What colors are you going to paint? Red White and Blue?

Tom

Thanks Tom,
Well if you go over there, see if someone will bring you over to my car. It's in that building. Hopefully it will be in Red, White and Blue colors by the end of September.