Setting the ride height

[aerosam]

Guys, following on from my recent post regarding front springs, i now have a lovely pair (oo-er) of 350lb springs installed on my front shocks.

Now i need to set the ride height, at the moment the spring seats are at the lowest height setting and the car is sitting about 3" off the floor, this is obviously too low. what is the correct ride height then? I'm guessing about 4 - 4.5" is that right?

I need to get thr front spot on to take measurements for the shocks for my rather bespoke rear suspension. (BMW semi trailing arms)

[spud69]

Originally Posted by aerosam

Guys, following on from my recent post regarding front springs, i now have a lovely pair (oo-er) of 350lb springs installed on my front shocks.

Now i need to set the ride height, at the moment the spring seats are at the lowest height setting and the car is sitting about 3" off the floor, this is obviously too low. what is the correct ride height then? I'm guessing about 4 - 4.5" is that right?

I need to get thr front spot on to take measurements for the shocks for my rather bespoke rear suspension. (BMW semi trailing arms)

Get the front as low as you can Sam so that you have about 4" clearance to your Sump / Bell housing giving you just enough clearance for humps. Then set your rear slightly higher.

The lower you can get the car to sit the lower CofG and less roll in the car, may even generate a bit of ground effect downforce but then someone would need to come up with a rear diffuser to fit the chassis (kick up the but) to get the most out of it. When on track days i'll drop the car by an inch or so and it does make a noticeably flatter ride.

AndyH

[aerosam]

Cheers Andy.

The car is going to be track use only anyways, so i might as well set it low and leave it low, speed bumps shouldn't be an issue. Although loading and unloading it onto the trailer might be!

I'm lucky with my beemer lump, it has a very low profile sump that i didn't have to modify, it's cast ally so i couldn't anyway. the sump is exactly level with the bottom of the chassis rails.

So about 4" would bo good then, fab tastic.

Thanks!

[tex]

you need to make sure the steering rack is sitting flat (the track arms) if they are not the movement up and down while your driving will alter the arcs they work in to alter the geometry.

aim for flat steering rack - flat lower wishbones (ie parrallel to the floor) take that as a starting point.

basing a cars geometry and handling around clearance to the floor isnt first priority.. firstly it has to drive! secondly it has to clear - if it doesnt then the engines too low - lift it.

i would recommend reading 2 books -

alan staniforths race and rally car manual

des hammill - how to build and modify sportscar and kit car suspension and brakes

some good diagrams and theory in there - and probably the best books iv read on the subject

[aerosam]

nice one Tex - cheers! I have loads of adjustment in my rack mounts so I'll set it, then probably fettle it when I take it on a track test day.