How do you have your Birkin shocks setup

[KiwiBirkin]

Hi im looking for advice from Birkin owners who still have the orignal Spax shocks on there car on how they have them setup for road use, I only use my Birkin on the road but it seems a rather stiff ride on bumpy roads. I have my tyres set to 20psi for both the front and rear.

 

Also I would like to know where to set the springs too, the bottom A arms have a slight fall away from the body to the tyre, I have been told the A arms should be level with the ground ??

 

Cheers Kiwibirkin

[pi7ot]

I would drop the tyre pressures to 17-18Psi for starters. I don't know wheat road tyres you use, but most likely they were designed for vehicles twice the weight of the Birkin.

 

Regarding the dampers, Birkin pilots in the USA have decided to run the front suspension with the front shockers set at 294mm between the eyes. We had a rash of bent lower control arms when the cars were set up lower to the ground.This problem had the positive benefits of reinforced arms being designed and made available.

Then the rear was set so that there was a 17 degree rake. which is what the UK Westies use.

 

One caution regarding the front suspension is the front lower ball joints. If you have the items that look like regular car ball joints as opposed to a rose joint. The non rose joint items like to snap just below the Nut in the spindle carrier.

 

m

[southwind25]

We have our shocks set midrange at the moment. We also went to other front springs because the ones that came with the car were way too tall! the lower A arms on ours is now about 1-2 degrees downwards(falling away) when fully loaded, and i think we have 296MM between ours. We lowered our tire pressures WAY down to 18 lbs..and would guess better tires would give a better ride yet. We also padded the stock seats a bit..LOL!(still need something better there) The ride is awesome for a car this size/weight.

[KiwiBirkin]

The front shocks have 294mm set between the eys on my Birkin so thats ok there then.

 

Southwind do you know which way you turn the little screw on the bottom of the shocks to set it up stiffer/softer as I dont know ?? I put a scew driver in there and could only get 1 click counter clockwise before no more turns but counted about 18 clicks clockwise before I stopped turning it as it seemed to keep going and it didnt want to mess with it untill I knew what was what.

 

Cheers

[slomove]

I would drop the tyre pressures to 17-18Psi for starters. I don't know wheat road tyres you use, but most likely they were designed for vehicles twice the weight of the Birkin.

That is probably a good number for many tire types but I did have a problem with my old Bridgestone S03 that 18 psi was insufficient to hold the beads on the rim when driving hard. I lost several times pressure on the track before I understood what was happening. At 21 psi it was O.K. On the other hand, my AVON ACB10 are happy with 16 psi.

 

Then the rear was set so that there was a 17 degree rake. which is what the UK Westies use.

Suppose that means 17mm? At 17 degrees the rake would be quite impressive ;-)

 

Gert

[pi7ot]

That is probably a good number for many tire types but I did have a problem with my old Bridgestone S03 that 18 psi was insufficient to hold the beads on the rim when driving hard. I lost several times pressure on the track before I understood what was happening. At 21 psi it was O.K. On the other hand, my AVON ACB10 are happy with 16 psi.

 

 

Suppose that means 17mm? At 17 degrees the rake would be quite impressive ;-)

 

Gert

 

I was close:p.

I have 12-15 in my notes.

To dial out understeer when your tyre set up is square.

It's in mm too. Sorry.

The Avo dampers are clockwise to stiffen. Spax probably the same.

The difference is when you have to soften the dampers. US made are counter clockwise to soften, but UK dampers are anti-clockwise to soften

 

m

Edited March 12, 2009 by pi7ot

[TheDingo8MyBaby]

I can confirm that spax is the same.

[KiwiBirkin]

I have just replaced my front Spax with new Gaz adjustable shocks and 250lb front springs and man what a diffrence they made to the car, it seems the front springs on the orignal spax were too long for the shock and we couldnt even get them to release pressure when the adjustment ring was fully slackend off to the bottom of the shock.

 

So on some advice from the place that fitted them and set them up im running 6 clicks in from full soft out of 30 clicks and 18psi on the new Toyo Tr1's and the car is just so much better over bumps, next up is to replace the rear spax shocks with new GAZ rear adjustable shocks and new springs, can any one tell me what rear lbs springs there running on there rear of their Birkin.

 

Cheers Kiwibirkin