air jack pressure

[spitfire4v8]

Can anyone tell me please how much pressure is required to lift a car like a tvr which has air jacks? is 100psi enough or does it need special higher pressure equipment?

[77racing]

divers air bottle I recon but no dought Andy Holden will be along to give you the full sp

[teamHOLDENracing]

Working pressure on the James Lister ones I had is 35 bar (~500 psi) per their catalogue. I used a big nitrogen cylinder because I got my gas free and it kept the system dry - but any old air will do. Unfortunately compressors to charge to this sort of pressure are very expensive...

http://www.jlsmotorsport.com/uploads/4/7/0/7/47074...

[spitfire4v8]

ah many thanks for that I will tell the customer he needs to spend some more money !

[Graham]

nick simpsons car had a set of air jacks about double the diameter of the usual ones. these worked on much lower pressure due to the extra area so ran of a normall air line.


not sure if they were one offs or not. all the usual suspects need a divers bottle

[450Nick]

Yeah mine will go up pretty quickly with much less than a regular air line - it all depends on the diameter of the piston in your jack, and the number of jacks - do some simple hand calcs and you can work it out pretty easily. The only reason the expensive ones use higher pressure is to either have a very small jack or to make it go up very fast - you obviously don't need it to move very quickly unless you're in a top race series, and bigger jacks don't make that much difference in weight so you can get away with a lower spec. Low pressure also obviously makes it much easier to seal!

On mine the race team made their own jacks with - they look pretty professional and just use a few O-rings, some ally tube with threaded ends for the cap, and a return spring inside to pull them up on de-pressure. I'm sure with a decent lathe, some ally and a couple of hours you could make some to do the job.

[sarbec]

compressed air is dangerous stuff would need press testing by specialists if you went down the make your own rout im sure your well aware of that joolz

[spitfire4v8]

it's the old eclipse t400 so i assume it's got something quite quick lifting in there. I will let the owner know the options and take it from there. replacements for something lower pressure might better suit the car now. cheers all.

[teamHOLDENracing]

Why don't you ask John Griffiths?

[spitfire4v8]

Yep will get the owner to ask john anyway but the owner was asking if I knew what sorts of pressures they worked at so I thought I'd ask here.

[Graham]

the ecipse t400 ran of dive bottles last time i saw it

[Guillotine]

Which is the norm, fairly small to move around and pretty cheap ti refill.

Britcar for it then jools? John thought it was going on the road!