Bilstein bump stops

[Matt7127]

I just replaced my rear bilstein HD's with sports in my 82 SC and was wondering if I should've cut down the bump stops due to it being lowered. The car rides at euro height maybe a tad bit lower and I'm wondering if I might have issues. The car is still up in the air so it won't take much to get these out again. The old HD's had a thick rubber stop. The new Sports have what looks like a poly bushing and a rubber bump stop.

[kandhmfg]

Originally Posted by Matt7127

I just replaced my rear bilstein HD's with sports in my 82 SC and was wondering if I should've cut down the bump stops due to it being lowered. The car rides at euro height maybe a tad bit lower and I'm wondering if I might have issues. The car is still up in the air so it won't take much to get these out again. The old HD's had a thick rubber stop. The new Sports have what looks like a poly bushing and a rubber bump stop.

I cut it down to about 1" of the big solid section and left 2 accordions on. Seems to work well even in racing applications. Before cutting it down caused a lot of oversteer as the shock bottomed out too early on the bumpstop. I think I got the recommendation off the Smart Racing website if it is still around?

I tried the progressive ones, but did not like them. Stayed with the modified bilstein setup as I describe above, plus its cheaper.

[Matt7127]

So you actually cut the solid (poly) bushing down? Wow, I was thinking of just cutting the rubber accordian stop. Do you have a link to smart racing?

[moneymanager]

Ask Bilstein where to cut. They have a diagram.
Did it on mine; maybe it has saved me once or twice and I just haven't noticed.

[PcarPhil]

Here ya go:

[kandhmfg]

I don't know if yours are the same type of bumpstops as mine had. I am attaching a photo of what mine looked like. The black rubber one piece bumpstop in the middle of this photo. The accordions and solid section are all one piece.

I cut the solid portion down to about an 1" tall and cut the top accordion off. Works great for me. Car is very low (race car). Before cutting down, the car was a handful when loaded in a corner. Works fine on the street as well. Don't get any rubbing using 245/45/R16 on 8" fuchs with SC flare.

[kandhmfg]

Originally Posted by moneymanager

Ask Bilstein where to cut. They have a diagram.
Did it on mine; maybe it has saved me once or twice and I just haven't noticed.

Moneymanager,

Off this topic, curious if you have dyno'd your 2.7 you list in your tag line. I have a similar 2.7 on my engine stand, but only 8.5:1 pistons and has small 32mm exhaust ports. Was thinking about bumping compression and porting exhaust to 35mm, already at 36mm intakes. I think it put down 165 rhwp before I pulled it out. Curious what you might be seeing on your engine if you know. Running a different motor currently, but thinking about going back to the 2.7.

Thanks,

Erik

[Matt7127]

Ok last night I installed the new shocks. I removed the solid portion and left about 2.5inches of accordian bump stop. The new Bilstein sports came with a solid plastic or poly stop and then on top of that have an accordian style stop like above which is rubber, it's accually 2 pieces. So I pulled the solid piece off, compared the old bump stop to the new one which is about the same size and installed. I placed the wheels on the car and pulled the jackstand and the car sits jacked, as if I put a lift kit in. I can fit my whole fist between the top of the tire and the fender. Here's a picture.

Do you think I'm bottoming out on the stop. Something just doesn't seem right. I've swapped out my wheels with 17's, was running 16s before. Here's a pic of the 16's and the ride height before the shocks. The car sat pretty low before

[SpeedracerIndy]

I just put the same shocks on mine and did exactly what you did, removed the plastic and trimed a bit off of the rubber stop. My car did the same thing. It was at euro height, and now sits too high in the rear. After two weeks and about 100 miles, it has relaxed a little bit but still sits too high for my tastes. I'm not hitting the bump stops because I can stand on the bumper and still compress the rear shocks quite a bit. I have an appointment to have it lowered back down on Monday. It seems to be common with putting Bilstein sports in.

p.s. Nice Audi in the background/reflection!

[Matt7127]

Interesting!!! That's a bummer because mine was at euro height also, I thought it would sit pretty much the same, I really dread trying to mess with the rear torsion bar, but there's no way I can drive it around like this, looks like a funny car dragster!!!

[Flat Six]

Matt, did you drive it after install/before taking pics? Fresh gas-charged shocks/struts can: a) lift car compared to worn units; and b) they'll 'settle in' a bit after a little normal travel up/down.

HTH

[PcarPhil]

Also did you do the final torquing of the lower bolt with the car on the ground (suspension compressed to normal ride height) or unloaded on jack stands? If torqued while unloaded that may be making the ride height situation worse. More than likely it'll sit down a bit after a hundred miles or so.

IMO it's to be expected that the ride height will raise a wee bit with new Bilstein sports vs. old worn out shocks. I'm actually banking on this with my car as my rear ride height could stand to go up 1/4-1/2". I've got new rear Bilstein sports going in this weekend.

[Matt7127]

:d

[wholio94112]

just want to thank y'all for this thread...about 1000 miles or so ago, i finished a suspension makeover with the rebelrsr front and rear bushings and bilstein sports, front and rear...when all was finally said and done, i hated the rear sports because they seemed so stiff and were obnoxious over every crack in the asphalt...the other day, i followed the smart racing diagram on cutting the bump stop and hard spacer, figuring, "what the hell?"...Problem solved...i guess i was bottoming out, as i do ride slightly lower than euro - according to wheel well heights anyways...thanks for the inspirational kick in the pants!!!

[Matt7127]

Ok I have to reindex! The rear sits over 27in! on average how long does it take to reindex the rear?

[Gretz]

Reviving an ancient thread here. I am getting ready to install my new rear shocks as part of a comprehensive suspension overhaul. The extremely tired old B6 rear shocks are being replaced by the yellow Street sport version. I am trying to find an answer on cutting the bump stops and/or poly spacer. If you look at the attached picture you will see the faint black line on the shock which is the maximum compression of the shock. And you can also see the poly spacer and bump stops.

My car is lower than euro height and I’d like to keep it that way. I have contacted Bilstein and the one tech I spoke with said that they have no recommendation on cutting bump stops. He said that he would do some research and talk to some of the other techs but after several days I have not heard back. Anyone have any sage advice on this?

[Superman]

What I heard is that those rubber thingies protect the shock itself. If the rubber is removed or cut down, then it becomes possible for the shock to compress far enough to destroy itself internally. Even if you lower the car substantially, I was told to leave the rubber bump stops in place and un modified. I may have heard that from Mr. Weiner (Rennsport). Perhaps Mr. Verburg can advise us here.

[Gretz]

I totally understand that. However, based on the maximum compression on my shock as indicated by that faint black line, it seems that I could remove or at the very least cut down that poly spacer significantly without danger of the shock bottoming out. I would definitely appreciate Bill’s input here!

[Superman]

When you place the car back onto the ground, the shock will shorten. Just from the weight of the car. Sometimes, like with 911s generally and certainly my 911, there just is not a whale of a lot of shock travel. Bill certainly knows WAY more about this than I.

[shoooo32]

Bilstein shock bodies are too long for lowered G bodies. You want static ride height at the mean of its stroke length, and a lowered car is off by inches.

Koni 1159 sport have a shorter body. You'll drag the swaybar before you bottom them out.