Suspension theorist needed...

[tony pashley]

The 1400 K, used by Robert Kenrick (son of...) at Prescott last w/e had an unusual fr. suspension set-up. Quite used to seeing non-standard arrangements on hillclimbers, but hadn't seen this before.

Top damper mount was outboard on a square-section transverse member which pivoted on the normal damper mount. (This made the spring a bit more upright and presumably lessened the falling rate in bump.) Only saw this briefly - cars were about to line up so it wasn't prudent to enquire...

 

First thought was that this was a fully floating spring/damper set-up - compressed from both ends - à la Radical (amongst others). But thinking back to what I saw, this doesn't seem to be the case. AFAIR, the inboard end of the 'new' member has an adjustable drop link, with the lower end pivoting on the lower wishbone bolt. (Altering that would be a round-about way of altering ride height, wouldn't it?, but do't know why you would - maybe the adjustable aspect is just an easy way of getting the length and the geometry right). Not sure if there was some other element I overlooked.

 

It had a coventional (for a race car) continuously adjustable FARB with drop links onto the wishbone; top wishbones were non-Caterham with rearmost tube parallel to axle line (nothing new I know, but am I right in thinking that when we adjust camber on 'normal' 7 wishbones, we are making a very tiny castor change too - don't imagine it can be too significant), with a rod-end ('Rose') bearing bolted/nylocked to standard upright - presumably with the taper reamed out. (Now that could make life easier if you dismantle the front end a lot).

 

So, anyone seen this? Comments, theories, etc? Anyone know what this might be achieving?

(Not sure if the Kenricks read this forum... I believe Dave K does - have you studied this car?)

[DaveK]

Tony

 

The object of the outrigger is to take the front damper too more of a vertical plane.

The suspension on roberts car is actually last years suspension off clives car.

The chassis are pre 96 so the damper/wishbone mount is combined, which with the wide track plus 1" each side would make the damper ratio too high.

The inner end of the outrigger is fixed via rod end bearings which are the adjustment to alter droop.

The wishbones are made by clive on a jig .

With the damper on a more vertical plane the damper ratio is less making the damper more direct acting hence you can use a lower spring rate to control wheel movement.

 

cheers

 

Dave

[tony pashley]

Thanks for the swift and lucid reply, Dave.

Congrats on your latest win, by the way!

Will make more of an effort to say hello next time around.

 

Edited by - tony pashley on 6 Sep 2001 08:24:00