[thormessiah]

Originally Posted by whyzee125

8k is really stiff up front and the front to rear ratio is too high which will cause it to pitch a lot.

6k/12k is a good balance as is 5k/15k

Ended up going with 6k/12k soo we'll see how the cat feels when I get it back next week. Out of curiosity what spring rates would 70 n/mm (400 lbs) and 120 n/mm (685 lbs) be? That's the spring rate for an Ohlins Coilovers set specific for high hp E92s.

[whyzee125]

Originally Posted by thormessiah

Ended up going with 6k/12k soo we'll see how the cat feels when I get it back next week. Out of curiosity what spring rates would 70 n/mm (400 lbs) and 120 n/mm (685 lbs) be? That's the spring rate for an Ohlins Coilovers set specific for high hp E92s.

There are lots of charts you can use to convert, looks like that's roughly 7k/12k

[Agypsy]

it's hard to believe the suspension manufacturers sell combinations like 8k/12k without a big disclaimer that you will not have a balanced ride.

stock e90 335i
145lb= 2.59kg
460lb= 8.2kg

stock M3 e92:
Front: 160 = 2.86k
Rear: 550 = 9.82k

pretty conservative as compared to the numbers posted. i'm getting ready to put an order in for BC coilovers and i've been researching a bunch and this forum is excellent! my e90 335 sedan is my DD and not going to be tracked. my main goal is for lowering and a touch more tighter/precise handling. i've got M3 control arms all around and 27mm/22mm sway bars. i don't think i need to go above the M3 spring rates. but i'm a bit confused as nobody runs the front below 6k.

can anyone tell me when ordering the specific rates, do i tell them in lb/in or kg/mm? also can they make them exact to within .5kg or do they round off?

cheers!

[bbnks2]

Originally Posted by Agypsy

it's hard to believe the suspension manufacturers sell combinations like 8k/12k without a big disclaimer that you will not have a balanced ride.

stock e90 335i
145lb= 2.59kg
460lb= 8.2kg

stock M3 e92:
Front: 160 = 2.86k
Rear: 550 = 9.82k

pretty conservative as compared to the numbers posted. i'm getting ready to put an order in for BC coilovers and i've been researching a bunch and this forum is excellent! my e90 335 sedan is my DD and not going to be tracked. my main goal is for lowering and a touch more tighter/precise handling. i've got M3 control arms all around and 27mm/22mm sway bars. i don't think i need to go above the M3 spring rates. but i'm a bit confused as nobody runs the front below 6k.

can anyone tell me when ordering the specific rates, do i tell them in lb/in or kg/mm? also can they make them exact to within .5kg or do they round off?

cheers!

Most aftermarket options run the front spring rate so high because they need to overcome the very short stroke of their damper setup. Stock setup has soft springs but decent travel and leans on a bump stop for added spring rate. Aftermarket options run the car lower with less travel so running a soft spring rate will just result in riding on the bump stop 24/7.

[Agypsy]

Originally Posted by bbnks2

Most aftermarket options run the front spring rate so high because they need to overcome the very short stroke of their damper setup. Stock setup has soft springs but decent travel and leans on a bump stop for added spring rate. Aftermarket options run the car lower with less travel so running a soft spring rate will just result in riding on the bump stop 24/7.

oh yes, of course, i should've thought of that! now it makes total sense. time to revise my plan slightly

many thanks!

[bbnks2]

Originally Posted by Agypsy

oh yes, of course, i should've thought of that! now it makes total sense. time to revise my plan slightly

many thanks!

yeah it's something I had to work around when I tried to run low front spring rates. I only had like 1.25" of bump travel with 336lb springs and it's just not enough.

[Agypsy]

Originally Posted by bbnks2

yeah it's something I had to work around when I tried to run low front spring rates. I only had like 1.25" of bump travel with 336lb springs and it's just not enough.

hi bbnks2, what spring rate did you end up going with front and rear? the info i've found so far is 5 or 6 years old with the exception of this thread, so i'm not sure if BC or any of the other companies have been on the forums and are now selling more balanced kits?

i'm thinking of going 310/725. i've got the a 27mm front sway bar which i'm thinking can be a good match. thoughts?

[1mGator]

Originally Posted by Agypsy

hi bbnks2, what spring rate did you end up going with front and rear? the info i've found so far is 5 or 6 years old with the exception of this thread, so i'm not sure if BC or any of the other companies have been on the forums and are now selling more balanced kits?

i'm thinking of going 310/725. i've got the a 27mm front sway bar which i'm thinking can be a good match. thoughts?

Hi Everyone ….. good thread both old and new. Like “Agypsy” I am looking for current information and am also looking at the BC Racing Coilovers for my 1m. I have been on H&R sport springs and stock shocks since new and now am going with a different tire set-up (265 front 295 rear) and am doing my “spring rate” homework …. BC says 7k front and 12k rear … I saw calculators submitted earlier but I am not an engineer lol. Any help appreciated …
1mGator