Bumpstop question/ Bilstein HD Rear

[golfdmb18]

I know running front Bilstein HDs with H&R Sports will cause them to wear out pretty quickly. I am just curious if the rears are any different.

I just purchased some H&R Sports from Turner. I have a set of brand new front Bilstein sports that I got cheap from work. We also have a set of brand new Bilstein HDs for the rear.

Will running Bilstein HDs in the rear with the H&R Sports cause me to ride on the bumpstops? I don't mind buying a new pair of Bilstein sports for the rear but since I can get the HDs on the cheap I thought I'd ask.

Thanks

[HarryPotter]

They will be fine, the sports aren't that low at all. You definitely won't be riding on the bumpstops.

[GotCone?]

if you're worried, trim the bumpstops down some.

[NC325iC]

internal bumpstops are a little difficult to trim

[dude8383]

internal bumpstops are a little difficult to trim

Aren't rear HD's and Sports the same or is it just the bump and rebound?

[sticksdaman]

Has anyone here actually trimmed the internal bumpstop on a bilstein sport? If so I have a few questions as there seems to be no clear cut answer on this subject.

[Van Westervelt]

Has anyone here actually trimmed the internal bumpstop on a bilstein sport? If so I have a few questions as there seems to be no clear cut answer on this subject.

Whats your Q? :)

[sticksdaman]

Will trimming the bumpstop void the warranty? How exactly is it done? Will it reduce the life of my shocks and how did it ride after they were cut?

I plan on running these with my coils and wanted to gain about an extra inch of travel without blowing them. No one seems to have gathered any solid info on this procedure and its results that i can find.

[Van Westervelt]

Yes, it will void the warranty. You push the shock tube out of the sleeve through the bottom. Then you cut no more than 1-1 1/8 inch off the top of the bumpstop. Then press the bottom plate back into the yellow sleeve. Rides like normal, but the shocks have another inch of usable travel.

[golfdmb18]

Any chance of ruining the shock by pushing the shock tube out of the sleeve? I would be doing it to new shocks, just curious. Thanks

[E30SPDFRK]

And how do you get it apart in the first place? How do you keep the fluid in?

[Stephen]

From what ive found through research so far, you use a chisel to pop the cap off and the fluid wont come out of that part.

Shame it voids the warranty though :/

[Van Westervelt]

You boys are silly. There is an insert inside of the metal sleeve. No fluid will come out.

That bottom zinc plated disc is just a back plate for the piston.

To pop them out, some people use a chisel, some use a table vise etc. The method that work best is the pants down method. :)

Put the nut on the top threaded section, and flip the shock upside down. Put the top on soft ground or material not hard enough to damage it, but hard enough to not move, hard ground ala dirt or grass. Grab hold and act like you are yanking the pants off the shock smacking it into the ground. Do it a few times and viola! If you do it slow, it will just decompress the shock as it is designed. You need to simulate it bottoming out rapidly to knock the bottom plate out. Its just a pressure fit.

[golfdmb18]

Will this also work for the rear shocks? Your picture shows the struts. I wasn't sure if the rear shocks seperate at the bottom like on the struts.

Edit: So after doing some research the struts have the internal bumpstop and the rears just have the external bump stop.




According to this guy the HDs and Sports are valved the same.

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

[Van Westervelt]

Yup, the rears use stock external bump stops.