No one! ...maybe not the right time a year. I understand. But long term I want to test this issue with the rising front of the air suspension car. As I now own another 109 (again) I'll test myself ...when the weather is warm and the car is on the road. Anyhow I'd be happy to do this research with the help of other air suspension car owners.
I now have Koni adjustable shock absorbers so any observations I make will be a lot different to others. Also,i replaced the rubber bushes on the hold down rods with urethane bushes. This made the braking a LOT different. The braking now feels very positive and the car sits very level even under hard braking. None of my 109's have ever pumped up in normal driving .I would imagine that pumping up beyond the set ride height indicates a problem with the control valve adjustments.
quote:12-14-2004, 11:49 PM #8 Tom Hanson MBCA Member
What the heck, try to stuff a MB 6.9 liter V8 in it. What a machine that would be.. __________________ Tom Hanson Orange County Section
adjustable Konis in a air suspension car? Do you have a picture? I understand your urethane bushings make the movement of the torsion bar much more precise but I guess if the car would pump up with rubber bushings ..it will do the same thing with urethane bushings..only more precise.
Adjustment of control valves: I think you mean the timing of the E and A bullets? I have done extensive investigation on this issue but These valves are like Swiss watches. They are relatively precise in terms of valve timing if they are adjusted correctly. i have tested valves from a US rebuilder and I found that the timing adjustments were even outside the MB specs (which call for max +/- 8mm of max Null Zone). I am adjusting timing much more precise to 2-3mm (+/- 1mm to +/- 1.5mm). https://www.youtube.com/watch?v=ryb3DrVd-X8
From what I know a more loose valve timing would make the car less reactive.... If you are braking and the car drops in the front- with a +/-8mm adjustment the A valve opens 'later'. So there is less pumping in a loosely adjusted car but it won't prevent the car from doing it (if it is as much as 50mm height difference as Chris and others are describing the phenomenon)... it is just doing it 'later'. However the E Valve in the loose adjustment opens also 'later' (16mm difference).
See.. with a very loose valve timing the car is on a different riding height depending if the car is coming top down or bottom up.
From what Chris is saying..he is an advocate for a tight valve timing adjustment..and I am too!
I guess none of this valve timing has great influence of a car that pumps up 50mm during driving and braking. I just want to know under what conditions this pump-up is happening.