20. Initial Alignment and Corner Weights

Should be a shorter post this time as I’m up to date with the posts, this is the work I did over Easter weekend.

I showed the scale pads I made in the last post and was keen to give them a go. Started setting them out and adjusting the height with the 6 feet on each pad with the help of a spirit level and laser level which I had previously used for measuring the roll cage.

To make it easier to get the car onto the pads I spray painted round each of the feet to mark the position so I could move them out the way, roll the car back into the garage and then jack the car up side by side and place the pad back into position.

First I was keen to see how well the turn/slip plates work. I polished the surface and used PTFE lube on both sides of the PTFE sheet (shown in the previous post). Got the car on and could instantly tell they where working as the plates moved out slightly as the suspension settled. Sure enough turning the wheel was very easy too.

Can easily turn the wheel by turning the tyre itself. And can actually shift the entire car side to side by giving the wheel (not steering wheel) a sharp yanked. So I was pleased with how they turned out, and a bargain compared to the price of proper levelling pads and turn/slip plates.

So the first weigh and the car was 962.5kg (just noticed now that is minus bumper) And the corner weight was a fair way off bearing in mind thats minus driver.

I checked castor before doing the corner weight and needed to add a fair amount. Please feel free to comment as I am no expert on alignment setup, but from some reading I was aiming for a few degrees of camber and around 8 degrees of castor. Is this the right way to go? No idea but it seems sensible to start with. I didn’t get a picture of it but bought a used longarce camber/castor gauge. Had to turn the wheels 15 degrees to measure the castor which was a bit of guess work so need to think of a way to measure the steering angle accurately but for the moment it will be fine as it should be similar left to right.

So after some playing with the front left and rear right ride height I got the corner weight to 50.2% with myself sitting to the car. Now what I am unsure about is how much of a difference the side to side weight distribution makes? 53.7% vs 46.3% of the left.

I had made a couple of fixtures to hold the string alignment poles a couple months back (in a previous post) which attach directly to the car which makes it nice and easy whilst jacking the car up to make adjustments. Some brick line off Amazon for a couple of quid with some bolts attached to the other ends did the job for the string itself.

I maxed out the front adjustment for camber and adjusted the steering arms. And these are the numbers i finished up with. The camber numbers are obviously negative too. Front toe slightly different based on having the steering wheel straight. Obviously will need a little play after the first drive.

So the rear needs some work. I worked out that 1mm of toe is equivalent to 0.132 degrees, so to get the right hand side as close to neutral as possible I would need a 0.73 degree shim (obviously doesnt exist) so to the closest 10 minutes is 40 minutes to have slight toe in or 50 minutes for slight toe out. Does this sound about right to you or have I cocked something up here? And for the left hand side with the same logic would be 10 minute shim for slight toe in or 20 minute shim for slight toe out.

Would be interested in peoples own experience with their setups. Keep in mind this is purely for track use.

Haven’t got an awful lot left to do now. Mapping is booked in with RRR Engineering for May so not too much longer left until it will be up and running.