billly sport vs. HD?

[Stevie30]

I'm running Eibachs w/Bilstein HDs front and rear. Works great, handles great.

[smonkbmw]

so have we arrived at a final answer about the Billy HDs? I want to run 4 HDs and m3 front springs/no spring pad (expecting a 1/2 in drop, front only)...

id agree that this is a good idea. wouldnt go any lower than a inch though on the hds. why not the m3 rears though?

[SpecM]

yea, HDs go for about $5/ea less on Pelican...

so have we arrived at a final answer about the Billy HDs? I want to run 4 HDs and m3 front springs/no spring pad (expecting a 1/2 in drop, front only)...

[Maluco]

so from what I'm reading, HD's cost less than sports in some places? Worldpac as you can see in the pic above, has both cost and list as the same... I guess some vendors see that the sport is more desirable and mark the HD's down.

[smonkbmw]

okay. so for sure it will be fine to run HD's on lowering springs?
some of us are on a budget. hehe. i just want to make sure.

and thus the spread of misinformation starts. great job hellabad.

might want to clarify that there is a reason you run sports with a higher drop race spring. before all the kiddies run out and buy twin tubes because you told them there is no difference between sports and any other bilstein.

i refuse to believe that the sports and hds are identical in performance. proof of this here:

Hmmmm. When i initially installed my H&R race springs on the bilstein HDs i had on my car, it bounced like crazy. I assumed the bump stop placement was different on the sports as the bouncing went away as soon as i installed the sports. Also would the longer tube change the bias of gas on either side of the valve? I've always felt it is a little easier to push down the last inch of compression then the first inch.

i can understand running a .5" drop eibach or h&r on a HD. but h&r race or ie3s i dont see how its possible, safe, or cost effective.

[Hellabad]

I have never mentioned that the reason the sports (p36-0335) are recommended for "shorter springs" to satisfy the TUV laws in Germany, where the spring is not allowed to come loose when the car is jacked up.

Thats why the sports are shorter when the struts are extended (not as far) but not when the car is on the ground.

If you already have the HD, just go ahead and use them, and if you are feeling the tiniest bit fancy, you can trim the internal bumpstops which is easy .

[e34john]

Money saving information AND hot 80's female pop/rockstars in the same tread?

good thread, great thread, would recomend to a friend!

thanks Hellabad.

The prices aren't too different. Shox.com even has sports for cheaper.

If only the TCs would work, those are about half the price of HDs or Sports. Some of the E34 guys I've have ran TCs with Eibachs or when they run Vogtland they used OE Sachs.

[Maluco]

newb...

[Bimmerista]

I ran H&R Sport on Bilstein HD for 2 years on my previous e30...it was perfectly fine.

[aSpecD_]

On an e30, yes.



Here is info from a 1998 discussion about this, in the early days of the internet on a list called BMW digest. Credit to Pete Read who got it from Bisltein engineers, who won't tell you this anymore.


E30 3 series 325e/es, i/is, M3
(3 series 87-91, 318i thru 86, front has 30mm piston, P30)
rebound / compression force at 52 cm/sec

Newton pound-force
N lbf (0.2248 x N)
------------ ------------------
Front:
P36 0132 Sport 2220/850 499 / 191
(P30 0133 Sport) 2220/850 499 / 191
P36 0136 HD 2220/850 499 / 191
(P30 0128 HD) 2220/850 499 / 191

Rear:
B36 2027 1475 Sport 1650/565 371 / 127
B36 2028 0720 HD 1650/565 371 / 127

[SIZE=4]I have attached a picture of me pressing on a Bilstein sport next to a Bilstein HD,

okay. so for sure it will be fine to run HD's on lowering springs?
some of us are on a budget. hehe. i just want to make sure.

my application is simply for daily driving and ocassional spirited driving.
i have already ordered LowTec 60/35 mm springs.. so HD's okay?

thanx hellabad
-jeff

[Pac1373]

Money saving information AND hot 80's female pop/rockstars in the same tread?

good thread, great thread, would recomend to a friend!

thanks Hellabad.

[einstein57]

Hmmmm. When i initially installed my H&R race springs on the bilstein HDs i had on my car, it bounced like crazy. I assumbed the bump stop placement was different on the sports as the bouncing went away as soon as i installed the sports. Also would the longer tube change the bias of gas on either side of the valve. I've always felt it is a little easier to push down the last inch of compression then the first inch.

[Sam Cogley]

No, but I'm only illustrating length here. All 318 are p30, and all 325 are p36. Lengths and damping are the same.

What Im saying is p30 HD is to p30 sport as p36 HD is to p36 Sport. It is just a coincidence (look at the damping numbers in that post) that p30 HD = p36 HD and p30 Sport = p36 Sport.

But that is all I have in my pile to show you a picture of.

I assume the p30 and p36 have something to do with the early 318 small-diameter struts? I think the M42 318s used the same struts as the 325s - I know my '92 318iC has the larger diameter struts...

[Hellabad]

so the larger diameter tube and piston is for nothing?

No, but I'm only illustrating length here. All 318 are p30, and all 325 are p36. Lengths and damping are the same.

What Im saying is p30 HD is to p30 sport as p36 HD is to p36 Sport. It is just a coincidence (look at the damping numbers in that post) that p30 HD = p36 HD and p30 Sport = p36 Sport.

But that is all I have in my pile to show you a picture of.

[smonkbmw]

so the larger diameter tube and piston is for nothing?