Ride height change with Bilsteins?

[phiba]

Can anyone give a rough idea of how much the ride height might increase when changing rear shocks from dual-tube Konis (no gas pressure) to Bilstein monotube sport shocks (high gas pressure)? My car is a 78 911SC.

What about total range of height adjustment using the eccentric bolt on the trailing arm?

[Steve@Rennsport]

All things being equal, the car's ride height will increase about 1/4" to 3/8".

[3.2Carrera]

will the ride height decrease after they get broken in? and what socks wont change your ride height? I really like the way my car sits but i am going to need new shocks soon, and i dont really want the ride height to increase ,what do you think??

Joey B.

[phiba]

Anyone have experience using the eccentric adjustment on the trailing arm? Does a change in offset at this end translate into an equal change in ride height, or is there some other factor involved?

[mca]

FWIW

I installed Bilstein Sports all around two weeks ago. In the rear they added about an inch to my ride height - replaced the Jap shocks the PO put on.

The front was offset a little b/c I removed those HUGE stock spacers that are on the underside of the tire well where the strut enters towers.

I am at 26" all around right now ... very sad ... but the ride/handling is much improved.

[ulrichd]

I changed from Boges to Bilstein HD. Initial ride height increase was almost 3/4" but after a week of driving returned to very close (1/4") to original height. Wait a while before you mess with the ride height.

Ulrich

[cab83_750]

I was a victim also. I paid for ht adjustment, alignment, then I stupidly changed the shocks to bilstein.

The ht increase was so ugly. I was told that they would lower once broken in; well, they might have lowered a tad, but they were still 'off-road' ht.

[phiba]

From what I understand (pls correct me if I am mistaken), Boge rear shocks are gas pressure shocks, although not high pressure gas like Bilsteins. Konis can be either a gas pressure version (30 series) or not (82 series).

Might this explain why some people get 1/4-3/8" increase (from gas pressure type to Bilsteins) and others get more (from non-gas to Bilsteins)?

The reason I am asking is, my car originally came with Bilstein Sports, but the PO changed the rears to Koni non-gas types. (The fronts are still Bilsteins.) Now the car rides 1" too low in the back. I was wondering if changing back to Bilstein Sports will help cure the problem. Well, I'm going to find out this weekend - just received my new shocks from Pelican today.

[bell]

Originally Posted by phiba

Anyone have experience using the eccentric adjustment on the trailing arm? Does a change in offset at this end translate into an equal change in ride height, or is there some other factor involved?

any movement of the eccentric bolt on the trailing arm will also affect the toe/camber, so an alignment is needed afterward imo, it will also only adjust height about .5"-1" if i remember correctly.
when i had my suspension apart to reset the ride height and add bil-sports i centered the eccentric bolts so when they aligned it they could go either dirrection, set my height on all 4 corners to a little lower than euro, after the alignment it made it feel like a brand new p-car.....well worth the big pia that the job is

[gr8fl4porsche]

Mine went up almost an inch!!

[cab83_750]

Originally Posted by gr8fl4porsche

Mine went up almost an inch!!

What she happy? Or, she wants more inches?

Sorry. Dry humor.

[phiba]

Looks like I got the raise I needed to get back to Euro height. So to conclude, Koni non-gas rear shocks to Bilstein Sports = +3/4 to 1 inch.

[3.2Carrera]

so will koni shocks raise your ride height ? or does it stay the same?

[phiba]

Based on my own experience, here is what I think, not what I know for sure. Don't take my word for it, check with Pelican and/or Koni. (I have found Koni customer support by email to be very responsive.)

For SC-era cars, Koni recommends 30-1214 or 8210-1159 for the rear. For the front, 86-1942 (OE Koni) or 8641-1039 (OE Boge). The 30-series (rear) are monotube high pressure gas shocks. 8210 (rear) and 86 (front) are dual tube type, no gas pressure. 8641 (front) is dual tube low pressure gas. The rear shocks I took out of my car were Koni 82K1962, also no gas pressure. These may be still available by special order from Netherlands.

So if you are starting with older Konis (no gas pressure), stick with replacements that have no gas pressure. If you have Boges, the Konis with low pressure gas should be the most similar. If you have Bilsteins, the 30s should give you similar ride height in back. Koni does not make replacement shocks for Bilstein front struts, only Koni and Boge.

Hope this info is useful.