[luckyu]

What spring rates are people running in front?

(And, are you planning to increase it significantly, like double the rate or more?)

Here is an incomplete table of known factory spring rates:

335i ZSP front: 137 lb/in measured (Vorshlag)
M3 front: 160 lb/in ???? (Orb)
335i BMW Performance front: 195 lb/in calculated (Mr. 5)
1M coupe front: 130 lb/in measured (AST)

I will start. My car is a 328i (rated 3362lb), and I'm using BMW Performance front springs, so I would expect it to be around 180 lb/in.

EDIT: If the 135i performance spring is 160, then it would make sense if the 328i performance spring is about 150.

[GaryS]

Not sure if you saw this:

http://www.e90post.com/forums/showthread.php?t=235797

[luckyu]

Originally Posted by GaryS

Not sure if you saw this:

http://www.e90post.com/forums/showthread.php?t=235797

Thanks Gary, yes and most of those numbers I think are fairly accurate.

I was trying to get a sense of how "popular" the higher spring rates were (above 250), but I don't think it came across very well. Oh well.

I've been wondering lately if there's any "missing spring" below 250 that people would like to have, but can't get. There are many people here interested in track times, but there must be some others who are interested in feel and driving pleasure, and would prefer to stick to softer springs.

[GaryS]

Well I'll add my springs. They are BMW Performance springs for 135i, which jah29 measured at 160 lb/in. That's the same rate the sticky post shows for E92 M3, but it shows 550 rear rate for the M3, and my car has rear 420. Afaik BMW always puts softer rear springs in the 1-series than the 3-series.

[luckyu]

Originally Posted by GaryS

Well I'll add my springs. They are BMW Performance springs for 135i, which jah29 measured at 160 lb/in. That's the same rate the sticky post shows for E92 M3, but it shows 550 rear rate for the M3, and my car has rear 420. Afaik BMW always puts softer rear springs in the 1-series than the 3-series.

That's interesting, did jah29 measure using a spring tester?

160 lb/in is the target I'm trying to hit right now in front. I may be asking you for your ride height in front very soon!!

The performance springs do appear to be relatively high rate in front.

[Gen_E92]

375 with Ground Control double adjustable front

[luckyu]

Originally Posted by Gen_E92

375 with Ground Control double adjustable front

You win! Still got all yer teeth? Is the car neutral steer?

[GaryS]

Originally Posted by luckyu

That's interesting, did jah29 measure using a spring tester?

160 lb/in is the target I'm trying to hit right now in front. I may be asking you for your ride height in front very soon!!

The performance springs do appear to be relatively high rate in front.

I'm pretty sure jah29 said he used a spring tester. Also 160 lbs agrees with the BMW advertising that says 135i Performance springs are 34% stiffer than stock.

I remember my car dropped almost exactly 10mm front and back as advertised. But I have Dinan camber plates in front now, which lifted it back up about 5mm.

[luckyu]

Originally Posted by GaryS

I'm pretty sure jah29 said he used a spring tester. Also 160 lbs agrees with the BMW advertising that says 135i Performance springs are 34% stiffer than stock.

I remember my car dropped almost exactly 10mm front and back as advertised. But I have Dinan camber plates in front now, which lifted it back up about 5mm.

Cool, thanks. My car is a 328i w/ performance springs, and it's at 13 7/8" (352 mm) in the right front. My front didn't drop a measurable amount when installing the performance springs.

Looks like the 135i performance spring is a good option for me. I'd prefer a little more ride height (more shock travel), maybe I can shim it a little.

[LOLrance]

400 swift linear springs on TCKline DA.

[lawwailok]

i have swift springs on Koni SA coilover, 336 lbs front, 616 lbs rear

[luckyu]

If you guys with coilovers could tell us more, like if these are track cars, I'd be interested in some overall info on what your goals were in choosing springs!

Also did you find that your daily drive improved or worsened with 250+ lb springs. We can guess it got stiffer, but overall is it more enjoyable for you to drive around town and on the freeway, or is it worse.

[tibra1]

336 F 672 R Swift Springs /AST 4200 D/A

[lawwailok]

as long as your dampening is adjusted to match the spring rates, it will not give you a harsh ride. i mean it will be stiff but not annoying stiff. ride height also play role to the ride quality too. my setup: 336fr/616rr, was recommended by Harold @ HPA and he said that will be ideal for more of a street with minor track duty. i could of go 400/800 but that will be stiffer.

when you go with coilover, make sure you set on the one with height AND dampening adjustment. those with only height adjustable might be cheaper but you will end up in a fixed rebound rate on the struts. that case, the lower you slam your car, the more bouncy it could be. ride will become annoying.

[Gen_E92]

Originally Posted by luckyu

You win! Still got all yer teeth? Is the car neutral steer?

The ride is firm but not jarring which I don't mind because the handling is so much better! Drove my parents around a few times and they didn't complain much either I had Eibach/FSD and FK coilovers before, both of them felt alot bouncier, but then I also upgraded to M3 subframe bushings and sway bars along with the new coilovers. The handling is absolutely night and day, and I haven't even played with the compression adjustment yet, been too lazy to do that

I think someone here mentioned that high quality dampers and proper valving is often more important than spring rate, they will not ruin your ride as long as you don't go crazy on spring rate.

[luckyu]

Thanks guys, very interesting info. Do you think advanced technology is necessary for good dampers, such as high-end AST 5200, Ohlins DFV, etc? Or, is it sufficient to get a "low tech" damper that responds quickly, such as monotubes promise to do.

[Tee212]

some good info in here!