Topic: 6.9 suspension conversion

[john erbe]

I note in your photo that the base of the shock appears attached on the arm in a more interior position than mine which I positioned in it's original place using the same bolt holes.

[john erbe]

Test. Mine at ride height.

[john erbe]

Better photo.

[ALV148]

Hi John. Thanks for the photos and reply
I am inboard as I am using the inner wing turret fixing to give longer travel hence keeping spring side clearance. As the original HPF set up give 2.25” of both upward and downward movement from sitting position. I have 6” in total but with a 425lb spring it uses 5 “ of that when sitting. I note your 10” spring is also very compressed?? Is the photo in sitting position ?? Do you still have 2.25” of travel left?? I need 2.75” of compression to have Sitting at the right level. Therefore 425x5 divided by 2.75= 772lbs. Does that sound right?? Cheers

[john erbe]

ALV..photo is with car down on ground. Attached shows measured shock eyelet to eyelet fully extended. Same measurements as given in catalogue but didnt help in my case because I dont use the upper eyelet rather the "stud mount" and inasmuch only interested in measure from bottom eyelet to underside of nut at bottom of thread. Travel is 4 7/8". A more ideal ride height for this shock would be higher toward the standard but I wanted lower in front as shown in photo taken of 6.9 with a 12" 450 rated spring and if I recall only two threads showing below bottom adjustment washer. That spring compressed to 8 1/4 " when loaded. However, the shock in that picture was the next size up and too big. Photo of side by side comparison to hydraulic strut prior to install. Found that out when I shot off a bridge at speed and clunk! Assumed incorrectly that went spring bound when in fact the shock probably bottomed out. Never said I was the smartest guy in the world. Swiched to 600 lb spring which compressed to 9" and subsequently drove for years. Result, higher in front more like standard ride height but stiff ride, tight handling, no body roll etc etc. Hence the change to the 450 which required a shorter shock. Hope this helps.

[ALV148]

Hi John.
Interesting that you thought the 600lbs were to hard. You say 4” Travel with 450lb. And 3” travel with 600lb  which makes sense as they both equate to 1800lb load. I need to double check the springs I had in stock? As i was sure they were 425 which travel 5 “ to standing which equates to a 2125lb load??I
May be they were only 360lbs 🤷🏼‍♂️🤷🏼‍♂️will let you know how I get on
Thanks again for info and photos. 👍🏼
Cheers

[john erbe]

i'll post photo when I get the 12" spring installed.

[raueda1]

ALV..photo is with car down on ground. Attached shows measured shock eyelet to eyelet fully extended. Same measurements as given in catalogue but didnt help in my case because I dont use the upper eyelet rather the "stud mount" and inasmuch only interested in measure from bottom eyelet to underside of nut at bottom of thread. Travel is 4 7/8". A more ideal ride height for this shock would be higher toward the standard but I wanted lower in front as shown in photo taken of 6.9 with a 12" 450 rated spring and if I recall only two threads showing below bottom adjustment washer. That spring compressed to 8 1/4 " when loaded. However, the shock in that picture was the next size up and too big. Photo of side by side comparison to hydraulic strut prior to install. Found that out when I shot off a bridge at speed and clunk! Assumed incorrectly that went spring bound when in fact the shock probably bottomed out. Never said I was the smartest guy in the world. Swiched to 600 lb spring which compressed to 9" and subsequently drove for years. Result, higher in front more like standard ride height but stiff ride, tight handling, no body roll etc etc. Hence the change to the 450 which required a shorter shock. Hope this helps.

Feel free to send me your old struts for proper disposal and to ensure that they don't fall into the wrong hands.

[john erbe]

In response to a PM asking how I made the upper connection: First I'll give credit where due to the guy down in Texas years ago who explain the concept, key of which is to take advantage of the rubberized boot up in the fender to which the strut is attached. Dont know how he he made the connection but here's mine. And, secondly to the local machinist used by the local NHRA guys who apprenticed as a kid in the German navy and without asking made all the parts out of crankcase steel. Quite simple, took strut with upper boot, shock, spring and spring perch to machinist. He made a cone which copies the upper end of strut. The base is turned to seat snugly in the perch.

[ALV148]

HI John

Sorted !!! here is mine with 12" 725lb Springs

[ALV148]

photos

[ALV148]

the photos have to be opened as they look squashed otherwise 

[john erbe]

ALV,

725 lbs. !!! How's the ride?  Looks like you chassis sits much higher.

[ALV148]

Yes  the 450SEL rear springs sit the rear up and therefore i have had to match the front, the front now sit 3/4" lower than the front

however the car rides high but fine

If i were to go again the 12" length is right, i would use 550 to 600lb springs instead and use shorter springs on the rear

but this is just temporary for me to get the car on the road

i am currently amassing and refurbing the part to reinstall the HPF suspension

here wheres i'm at

thanks 

[daantjie]

Nice work on those original leak lines, they are now NLA from Benz