Jump to content
Click here if you are having website access problems ×

Suspension guru sought


tiptree

Recommended Posts

Have been trying to set my '94 K series dedion suspension up and need advice/confirmation please for front. 155/157 ride height back, tried to do 145 front n/s 147 front o/s. Questions:

 

That 2mm difference (for my weight) translates into about 12mm on the platform position on shock absorber. I would have expected 3mm at most. Does this simply mean the shocks are not a match and that I don't need to worry or is my car wonky?

 

I thought that by having 145mm rh at front I would get 85mm clearance under sump. I have no more than 78mm. Am I missing something simple here?

 

Thanks for any answers.

 

 

 

 

Tomorrow's a good day for it!

Link to comment
Share on other sites

I think you have been proceeding on the basis of a little knowledge.

 

If the car is straight and level *when you are in it*, then you have discovered the right answer, but the corner weights may still be miles out. If you try and guess loadings and ride heights when you aren't in it you are on a hiding to nothing.

 

Your dampers are fine by the way - they make no contribution to the static position. The geometry could well mean a 12mm difference in spring platform position depending on what is going on at the other corners.

 

You are equally in danger of getting lost by trying to set up specific ride heights. You haven't considered the tyres and wheels you are running, that could mean your ride heights *should* be up to 10mm in either direction from any nominal figure.

 

Start by setting everything evenly - don't over complicate matters. Have a read of this. If you have any questions, get in touch using the email address under my profile.

 

Peterid=teal>

253 BHP K-seriesteeth.gif, no gearboxbum.gifid=red>

 

Edited by - Peter Carmichael on 20 Jun 2002 12:07:10

Link to comment
Share on other sites

Ouch! "a little knowledge". I'm 45 and have never had anything more than a little knowledge about anything!

 

Anyway, thanks for the comments, I was working from Caterham figures I thought but there, could be wrong again. Assume the car is level when I'm in it, it rode and handled well before I started messing around. By moving from 14 to 13" wheels I changed the ride height by some 15mm (measured) and thus lowered the sump to an unacceptable level, less than 70mm (for mainly road use).

 

Maybe I should buy a motorbike!

 

 

 

 

 

 

Tomorrow's a good day for it!

Link to comment
Share on other sites

It is amazing how little ride height you can get away with. I have run with about 50mm clearance under the sump with 13in wheels ACB10s for 4 and a half years of road use. Admittedly my spare engine is on its third wet sump and the dry sump does improve clearance. You have to scan the road ahead, avoid straddling crowned roads and never run over cats eyes down the centreline of the car. Apart from that it works OK.

 

My preference is for the lower wishbones to be set parallel - certainly no lower. Never worked out what this means at the side rails.

 

Peterid=teal>

253 BHP K-seriesteeth.gif, no gearboxbum.gifid=red>

Link to comment
Share on other sites

Thanks Peter, I'm just a little sensitive about the sump clearance as I had to hit a brick centreline of the car when it came off a tipper and it wouldn't fit under the sump!! Next day I grounded on the crown of a single track road, two up, under hard braking for a sharp corner. Anyway, Caterham had some more views on it today and between these bits and past threads, I've got somewhere close to what it perhaps should be and I'll take it from there. Just looking forward to tryig it this weekend now!

 

 

 

 

Tomorrow's a good day for it!

Link to comment
Share on other sites

Hi Andy, neat article last month in LowFlying. I was kind of thinking of keeping the set of five 14" pristine silver wheels with almost unused Avons (spare new) for winter use. Let me think about it for a while... I really want a 4into 1 exhaust and an FIA with boot cover and... well you know how it is!

 

 

 

 

Tomorrow's a good day for it!

 

Edited by - tiptree on 20 Jun 2002 19:55:44

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...