318is GC Spring Rates

[royalflush313]

well my car is a dd/auto-x car...I would like to do some track events though. I don't know a ton about spring rates so I don't know "how" stiff 650 is other than really stiff ;) I have bav suto springs right know..does anyone know what rates those are just as a comparison. and like I said I'm not really worried about a harsh ride...I just don't want it to hurt (ie rip apart) the car.

thanks for the help guys,
Charlie

For comparison:

pulled from FAQ section

All numbers in Lbs/in Front -> Rear

E30 spring rates

Stock M3 -> 140 -> 250 (others say 100,300?)
Dinan Sport -> 172 -> 300
H&R Race -> 315 -> 570
H&R Sport -> 185 -> 380
Eibach Pro-kit -> 102 -> 277
Eibach Race -> 160 -> 445
Ireland Stage 3 -> 315 -> 570

[asubimmer]

hmmm.... would a 550/650 rate screw up a car on the street? I'm guessing the bav's are about 175/350ish? How harsh would a 550/650 setup be on the street?

[asubimmer]

ahhh well I decided that it would just be better to go all the way and just get a Korman suspension instead of getting GC's. Thanks for all the help everyone and hopefully the info can help others that are looking at getting GC's.

[Digitalwave]

hmmm.... would a 550/650 rate screw up a car on the street? I'm guessing the bav's are about 175/350ish? How harsh would a 550/650 setup be on the street?

Just for reference since you've already decided against the GC's: GC/Eibach ERS springs are linear, meaning they are the same rate from the very beginning to the very end of the spring travel. Every other non-race spring setup (like H&R Sport, H&R Race, IE Stage 3) uses progressive springs. That means the spring is a lot softer at the beginning of its travel, and gets stiffer the closet it gets to bottoming out. Those rates listed above are for the stiffest point of the spring, which you probably don't utilize in every day driving.

For street use, the comfort level of a progressive spring far exceeds that of a linear spring.

[2002maniac]

550 seems pretty stiff up front. I would try 500 first.

[Driver1]

any opinions on a 550#/650# setup for a track only 318is M42 car?

Looking for a good coilover setup for the brick.

[2002maniac]

track only 318is M42 car

Go stiffer if your shocks can take it. 550/650 would be streetable IMO

[Driver1]

What would be a better, or at least more commonly used setup?

[IS]

b/c of the gb...thats the lowest they are selling...but thats cool because I want stiff ones anyway. Does anyone have GC's #?

Thanks guys

Thats kinda retarded, IMO. Sacrificing your suspension to save a few bucks, when you're spending so much already. Get proper rates. Those are damn stiff on a 325 and your car is even lighter. I can barely stand to drive my car on anything but perfect roads with 440/700. Bear in mind that this car is solely my toy and once I have the means, I'd like to make it a dedicated track car.

550/650 doesn't seem like enough bias at all. the 475/650 is more reasonable, if you choose to go with such insane spring rates.

[IS]

For street use, the comfort level of a progressive spring far exceeds that of a linear spring.

Hardly. The range of spring travel before you reach the ultimate spring rate (where the soft coil collapse) is so small, it only makes a difference over small imperfections. Over the serious road imperfections, it makes zero difference.

[asubimmer]

I'm either going w/ some H&R races or some custom H&R's. I don't think I really need GC's.