[Beisofmarko]

Hi,

I have currently on my car koni yellows paired with some hartge lowering springs
and i have no idea what kind of lowering and stiffness they are.
They have part numbers on them but can't find any information about them, probably so old.

I have to replace my rear shocks because of a leak
and would like to refresh springs at the same time since they are atleast 14+ years old.

I'm bit concerned how to select correct ones to maintain around 1 finger gap that i currently have.
What springs would work best with koni yellows on E92 335i, wheel setup 235/35/19 & 265/30/19.

I've been also looking some BC racing DS / ER coilovers to not have to worry about getting height right,
but so many mixed reviews about them being bumpy or something else so maybe
i'll just stick with koni setup as its been proven good.

So what springs are people running with their koni yellows on e9x chassis?

Thanks beforehand!

[whyzee125]

Here would be my recommendations in order from highest to lowest ride height:

Diann - very close to M sport height, a tad lower and stiffer
Eibach pro kit - probably the best bet for 1 finger gap
H&R sport - absolutely must run e36/z4 bump stops but it’s a good set up once paired with these. Pretty low
Twin S tech - needs the same bump stops as above and I wouldn’t recommend them without also getting e30 front perched and pads but then they ride great, are a good bit softer than the H&Rs and they’re cheaper too
Swift spec r - these are linear but I wouldn’t recommend them as they tend to sag and the rear height seems to be all over the place. They also recommend the OE bump stops but they will literally have no travel with them. Haven’t heard any reports of people using the e36/z4 stops so unsure how they’d be with those

[Beisofmarko]

Originally Posted by whyzee125

Here would be my recommendations in order from highest to lowest ride height:

Diann - very close to M sport height, a tad lower and stiffer
Eibach pro kit - probably the best bet for 1 finger gap
H&R sport - absolutely must run e36/z4 bump stops but it’s a good set up once paired with these. Pretty low
Twin S tech - needs the same bump stops as above and I wouldn’t recommend them without also getting e30 front perched and pads but then they ride great, are a good bit softer than the H&Rs and they’re cheaper too
Swift spec r - these are linear but I wouldn’t recommend them as they tend to sag and the rear height seems to be all over the place. They also recommend the OE bump stops but they will literally have no travel with them. Haven’t heard any reports of people using the e36/z4 stops so unsure how they’d be with those

Forgot to mention, i allready have e36/z4 bumpstops and supersport suft015 lowering perches on front.

Maybe i'll consider trying eibachs or h&r then, i believe these hartges that i have
are also either rebranded eibachs or h&r. Can't just find any info with part number they have so have no idea what kind of lowering they are marketed for.

Eibach pro kit are easy to obtain here and seems to be just around 300euros for kit.
And the 1 finger gap is just what i currently have, i can live with a bit higher stance also as i'm allready getting some rubbing if i have 2 or more passengers.

[whyzee125]

Originally Posted by Beisofmarko

Forgot to mention, i allready have e36/z4 bumpstops and supersport suft015 lowering perches on front.

Maybe i'll consider trying eibachs or h&r then, i believe these hartges that i have
are also either rebranded eibachs or h&r. Can't just find any info with part number they have so have no idea what kind of lowering they are marketed for.

Eibach pro kit are easy to obtain here and seems to be just around 300euros for kit.
And the 1 finger gap is just what i currently have, i can live with a bit higher stance also as i'm allready getting some rubbing if i have 2 or more passengers.

Your lowering perches + lowering springs will put you lower than you want to be with most of those springs, except for maybe Eibach. The e30 perches raise the height to get you closer to the 1 finger gap. Eibachs with stock perches should put you roughly one finger gap all around

[mattanderson]

Do springs wear out?

I wouldn't be concerned about 14-year-old springs in the slightest.

If you like the spring rate and ride height, why not just reuse them?

[Beisofmarko]

Originally Posted by mattanderson

Do springs wear out?

I wouldn't be concerned about 14-year-old springs in the slightest.

If you like the spring rate and ride height, why not just reuse them?

That's the thing, i don't really know if its needed or not.

We get long winters and roads get blasted with salt here in finland so my springs
atleast look allready pretty rusty from outside and since they are around 14-18 years old,
i thought that maybe it's good to refresh them also for peace of mind.

[steifan]

Perhaps coilovers isn't a really good idea for salty nordic winter use (or at least that's what I believe). I have a 325i 2006 thats I only used in summer in Sweden and it's still rocking those m-sport springs (looking fine and ride height looks good too)) but I will probably replace them with Eibach Pro-kit or similar when i replace front struts for Bilstein B8 (already have a pair on the rear). Soon at 140000 km. I am a little skeptical towards Eibach because I fitted a B12 kit on my E46 11 years ago and I think the rear springs only survived 2 years before cracking in the ends (progressive springs) in multiple places but the fronts are holding up still in 2024 (just some minor rusting here and there, car mainly used in winter). My previous Lesjöfors solid thickness rear springs where put back and they've held up ever since

[lowrydr310]

Originally Posted by steifan

Perhaps coilovers isn't a really good idea for salty nordic winter use (or at least that's what I believe).

Why not? Shouldn't make any difference compared to standard strut/shock/spring setups, as long as you're buying from a reputable manufacturer and not no-name junk.

[Tambohamilton]

Originally Posted by Beisofmarko

That's the thing, i don't really know if its needed or not.

We get long winters and roads get blasted with salt here in finland so my springs
atleast look allready pretty rusty from outside and since they are around 14-18 years old,
i thought that maybe it's good to refresh them also for peace of mind.

If the springs are rusty (flaky rust, coating peeling off) then it's sensible to replace.

I recommend against eibach, because the springs are not significantly stiffer than m-sport, but they are much lower; you just ride the bump stops all the time.

[steifan]

Originally Posted by lowrydr310

Why not? Shouldn't make any difference compared to standard strut/shock/spring setups, as long as you're buying from a reputable manufacturer and not no-name junk.

Yeaah sure, I guess only stainless steel would suffice for threaded parts and I'm not sure thats very common in reputable brands chinesium parts or no-name junk chinesium parts


This might be something -> https://www.kwsuspensions.co.uk/technology/inox_line

[TheMidnightNarwhal]

Yeah I wouldn't change springs unless needed, like snapping in half because of rust.

But OP FWIW I had coilovers on my first 335is that was totalled. I daily my car in winter and yeah I tried to put fluid film and all that but after 2 season I didn't really care to much. My plan was to raise it at most and lower every season but quickly forgot about that. Like it was still doable but it's a pain to grease all that and etc. If you really want coilovers I'd get KW stainless, but then for the price I just want springs lol.

So on my current 335is, I just went the springs route with H&R sport sprigs and I do like it. I just wanted to make the car look more sport with no wheel gap.