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MG MGB Technical - front suspension with coil overs

Does anyone use Henk-Jan Vonk's front coil over setup (http://www.britishv8.org/MG/HenkJanVonk.htm)?
I tried to build one according to information I found on internet but am not happy with result. Coil overs suppose to be same as from Moss (Part No. TMG49025) with 6 x 2.25 inch springs, rated at 525 lb/inch (http://forum.britishv8.org/read.php?7,31688).

It looks that I missed correct dimension of bottom bracket so would appreciate if anyone can help with exsactt dimension.

toni

Toni Kavcic

Toni,
What exactly are you not happy with? The mods, as shown in the link, look very simple.
Allan Reeling

Hi Allan,

I measured ground clearance before and after installation and found that is car with coil overs 15 mm higher. That does not make me to many worries but fact that has shock very small travel in top direction (when body goes down) is most probably not good sign. I have feeling that I made to long bottom bracket so distance between top mounting point (ax of old shock absorber) and bottom I to long for that particular shock absorber.
Toni Kavcic

Toni;
1. How are you measuring the ride height? I assume that's what you mean by ground clearance, or are you meaning my point 4 below?. The usual way ito measure ride height is from wheel centre to bottom edge of Stainless side strip. Mine are 370mm but they are both using lowered suspension R/B cross members. (V8's) Chrome bumper will be a touch lower than this, normal R/B higher.
2. The coil-overs in the link have an adjustable spring pan, have yours?
3. Lack of what you consider sufficient compression travel (when body goes down) would suggest the bottom bracket is too short, not too long, or of course the damper is too long.
How much free travel have you got when the load is on the spring?
4. There is obviously a limit to how much protrusion from the bottom of the old spring pan is acceptable. On the photographs it certainly looks less than 50mm.

Allan Reeling

I measured ground clearance on front cross member (rubber bush to flor). This is between points A and B according to picture
Yes spring pan is adjustable. I tried different positons but no influence. My conclusion was that is damper already seating on rubber insert that prevents metal to metal contact on compression stroke. Body barley moves if I seat on bumper - but that is not a reference with my 70 kilos .
My estimate is that is there maybe ½ inch of free travel. I am aware that is problem in bottom bracket but not to make too many trails and errors would be easier if some could provide exact dimension.

And there is always possibility that I have wrong dampers 


Toni Kavcic

Toni,
Up to a point that ground to cross member dimension is not critical. Measure the ride height as I suggested. If it's sitting on the original bump stops as you suggest then the spring pan needs to be screwed up to raise the ride height. This will not only increase your ground clearance but will also increase the available compression travel Your coilover installation has not changed the original suspension geometry, hence riding on bump stop indicates it is just too low.......wind it up!
Picture would be good.
Allan Reeling

Hi Allan.
Suddenly all what you wrote sound to me very logically. Unfortunately I dismantled coil overs and put back Armstrongs for my trip to holidays. Will try that when come back home and let you know result.
Toni Kavcic

I have the Moss coil over system fitted to my MGA (with MGB front suspension, GAZ dampers). While it works okay it is very hard on the coil over poly bushes - need replacing regularly (my first lot lasted less than 3,000 kms included track and hillclimb driving). While not expensive to replace it is a pain to do regularly.
Mike
Mike Ellsmore

This thread was discussed between 17/08/2017 and 19/08/2017

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