[mob17]

Tried searching but couldn't find a definitive UK answer.

What are the front and rear OEM M Sport spring rates for a pre lci e92 335D?

[Aragorn30d]

fronts are around 150 and the rears around 450 from what i've read online.

Do you need it any more accurately than a general ballpark?

[mob17]

Originally Posted by Aragorn30d

fronts are around 150 and the rears around 450 from what i've read online.

Do you need it any more accurately than a general ballpark?

Would be great to get a more accurate figure, need to do some calculations.

I also read that its roughly 140-150 up front and 460 at the back, but thats a figure given for the whole of the e92 range. I'm sure the 335D has different rates, especially up front.

I might try emailing some OE part manufacturers and give them the part number, they should be able to give me a datasheet or something. Unless someone knows?

[Aragorn30d]

M3 is 160 and 550, so its unlikely the 335d is going to be much stiffer than 150ish up front.

[mob17]

Originally Posted by Aragorn30d

M3 is 160 and 550, so its unlikely the 335d is going to be much stiffer than 150ish up front.

You're probably right.

Think i'm going to email some OE companies to get an exact figure.

[mob17]

Not getting any luck on realoem. Apparantly theres no matching parts when i click on front or rear coil spring! Tried entering my vin and generic car.

Does anyone have the part numbers for the m sport spring for a pre lci e92 335d?

[Aragorn30d]

Yeh just looked, and tried a few different cars, no springs appear to be listed at all, even tried an F30 and E46 but none for those either.

[mob17]

Originally Posted by Aragorn30d

Yeh just looked, and tried a few different cars, no springs appear to be listed at all, even tried an F30 and E46 but none for those either.

Really strange, maybe the site is playing up but it shouldn't do.

Guess a call to the dealer is in order.

[mob17]

I can't believe this. Rang my local dealer and he refused to give me the part number for the springs! Saying its not their policy as i could go buy it elsewhere. Ridiculous!

Might try another dealer.

[mob17]

ok i got the part numbers specific to my car/options from another dealer:

Front 31336767379
Rear 33536767344

Next step, spring rates.

[mob17]

Apparantly eurocarparts have the rights to the springs and sachs/lemforder dont have the data

[Icekube]

what are you trying to do?

[Aragorn30d]

TBH its the kinda info that they just wont give out.

The sales and marketing people dont know, and the actual technical/engineering folk that do wont ever entertain a request from Joe Public for the info.

Get some springs and have them measured by a suspension specialist?

[mob17]

Originally Posted by Icekube

what are you trying to do?

Just wanted to work out the front/rear wheel rate and ride frequency of stock 335D suspension and compare it to mine. For that i just need the spring rates of the stock 335D.

Originally Posted by Aragorn30d

TBH its the kinda info that they just wont give out.

The sales and marketing people dont know, and the actual technical/engineering folk that do wont ever entertain a request from Joe Public for the info.

Get some springs and have them measured by a suspension specialist?

I'm getting the same feeling mate. Sachs/lemforder/boge all come under ZF, and they don't have the info or can't be arsed lol. Last step is to try ECP but i am almost certain they don't have that info.

I wish i never sold my m sport springs, i could've just gotten them measured up like you say. I don't think i'll buy the springs as it's just for some stock calculations, don't need to do them but it would've been nice to see.

I'll update this thread if i get any luck.

[Aragorn30d]

Given the weights involved, i doubt 150 or 160 will make a huge difference to the frequency.

The error in your calculations of unsprung weight are likely going to be be far larger than the errors in spring rate.

[mob17]

Originally Posted by Aragorn30d

Given the weights involved, i doubt 150 or 160 will make a huge difference to the frequency.

The error in your calculations of unsprung weight are likely going to be be far larger than the errors in spring rate.

Thats true. But it would have been nice to get the exact rate front and rear. Even if it was just a confirmation of the 150/450 rate. I hate not knowing!

I'm using the corner weight data i have for my car, and estimating the sprung weight by taking 50kg per corner off. Is 50kg a good estimate?

[Aragorn30d]

its a reasonable estimate yep

Big wheels and heavy brakes will probably shove it up a bit.