HDs how low...

[e30patalohas]

So I have a set of Bilstein HDs on my 84 325e that's 4 wheeling right now. How low can I go with the HDs before I run the potential of turning them into crap?
1", 1.5" or 2"???

[dantheman]

I don't think it's how low you go as much as the spring rate of the springs you end up using. I have an Eibach Prokit from an M3 with HDs that gave me about a ~1.75" drop and they've held up great. However, the spring rate on the prokit is very low and the suspension is soft.

If you went with something stiffer like for example, H&R race, the HDs wouldn't last you very long at all.

Here's a list of spring rates to give you an idea..

Spring---------------------Front(lb/in.)-------------Rear(lb/in.)

Stock 325i*-----------------------106------------------------245
Stock 325is*----------------------118------------------------265
Stock 325ix*----------------------106------------------------308
Stock M3*-------------------------114------------------------314
Stock M3--------------------------140------------------------250
Dinan Sport-----------------------172------------------------300
H&R OE Sport---------------------180------------------------380
H&R Sport-------------------------180------------------------380
H&R Sport (29664)---------------200------------------------285
H&R Race-------------------------315------------------------ 570
H&R Coilovers***----------------340------------------------380
Eibach Pro-Kit--------------------102-------------------------277
Eibach Race----------------------160-------------------------445
IE SIII----------------------------315-------------------------570
Koni Coilovers-------------------342-------------------------407
Cosmo Coilovers----------------450-------------------------560
Tokico----------------------------165-------------------------265
TMS J-Stock**-------------------680------------------------1026
Alpina(est.)---------------------~200-----------------------~350
FK 60/60 cup kit-----------------379--------------------------379
Vogtland Standard***--------115/197-----------------------360
Vogtland CS***---------------137/200-----------------------400
Vogtland--------------------------225--------------------------360
Intrax-----------------------------126--------------------------250

[dantheman]

Btw: I am going to be ordering a set of Cosmo or GC coils with high spring rates. I'll run them with the HDs and let you know how quickly they blow up lol.

[e30patalohas]

Ahh, ok so spring RATE is much more important than actual drop, unless u get nuts lowz! Thanks for the information, makes things more interesting for me with more options now.

Keep us posted on how long it takes your HDs to impode, Dan.

Thanks!

[MR 325]

I'd run them on anything up to H&R Sport. A buddy had them in his car with those springs and they were excellent.

[dantheman]

.
Keep us posted on how long it takes your HDs to impode, Dan.

Will do, sir!

I'd run them on anything up to H&R Sport.

This.

[nando]

the solution to this problem is to get them revalved. :)

[Mr. Tasty]

are HD's the same as Sports when it comes to revalving? Are Hd's revalved to 450# springs the same as Sports in the same condition?

[nando]

Yes

[e30patalohas]

Anyone know how much it would be or what the process of regaining HDs to Sport involves?