Chassis Height

[Longboarder]

I think your basic problem is the shocker itself is too short. Assume an ideal rest position (with the car standing on it's wheels and you in it) of the lower wishbone horizontal or even sloping down 5 degrees to the wheel. Just jack up the front of the car. How far can the wheels droop? You should have available movement of the wheel down further from rest (extending the shocker) of about 1.5 inches and up from rest of about 3inches. This is limited by the length of the shock. Your last post saying if you screw up the spring collar they top out means they are too short when extended. I would think that you need shocks about 2 or even 3inches longer. Same spring strength or just possibly 30-50lb stronger and 2 or 3 inches longer. These are just guesstimates as I haven't seen the car and some measuring and trial is needed.

Incidentaly regardless of the bends in the lower wishbone, in effect it behaves as if it were a theoretical bar pivoting on the centre of the inner bush and the centre of the outer ball joint so the situation is worse than at first appears. Pic below. Bringing the lower end of the shocker inboard further puts excess stress onto the lower wishbones and risks bending them.

 

Nigel

[Guest Tim Norman]

Good Point Nigel, I remember with the shockers I got there were two sizes initially I had the long ones on the rear, swapped them to the front and put the longer springs with them and solved the ride height problem.

[gaz0571]

yes martin my springs are 9" 350lbs.

[Guest MartinP]

recounting

 

Both Gaz0571 and my chassis have been modified by GBS

The conversions are slighly different in that on mine all the sliding pillar structure was taken off by me prior to shipping to GBS. This meant that they had to fabricate a headlight mounting plate incorporating the top shock mounting.

 

GAZ shock are the same

14" open

9" closed

 

Gaz0571 has 10" 350lb springs

I have 9" 350lb springs

 

 

Gaz has taken a few measurements off his car

 

Height from ground to lower wishbone pivot bolt (wishbone horizontal) 6.25"

Distance between shock mounting bolts with car weight on 12"

Distance top shock pivot bolt to stainless side panel 2.25"

 

My car

 

Height from ground to lower wishbone pivot bolt (wishbone horizontal) 6.75"

Distance between shock mounting bolts with car weight on 13.5"

Distance top shock pivot bolt to stainless side panel 1.25"

 

Following Nigel's comment, it looks like I am at the end of the travel, with only 1/2" or so until the shock is at full extension.

 

The fact that my top mounting is 1" further away from the bottom mounting than Gaz's only decreases the available working length of the shock.

 

 

so I may have to go for longer shocks, or make new lower brackets to reduce the distance by an inch.

 

I will also make some 1" spacers to push the spring up.

 

 

Will keep me off the streets for a while

 

Thanks for the help

 

martin

[Guest MartinP]

update,

 

had a good chat with the guy at Dampertech, he recommended jacking the car up to the required postion, with the wishbone horizontal, measuring the distance between the upper and lower shock mounting holes. this will give the length at the mid point of the shock travel. from this a correct length can be arrived at by looking up the dampertach chart.

( a very similar line of thought as longboarder)

 

the 140/095/12 shocks were sent back to GBS and they have now supplied 160/105/12 units with 10" 350lb springs

 

These are 16" open

10.5"closed

 

 

the car is now sitting with the top wishbones level, 14" between the mounting points with the engine weight on so I am a lot happier.

 

Thanks for the thoughts & comments

 

Martin