Jump to content

Discovery2 active cornering


Recommended Posts

Found this in RAVE about the D2 ACE system, the pumps operational pressure is 135bar or 1958psi, displacement of 8.5cm3/rev, output flow of 7ltr per min @ 775rpm to 9.25ltr pm @ 7625rpm.


Mmmmm..........135 bar????? Considering the jumping cars rarely go above 20 bar - and the disco barely 'jumps' - it is more likely 135psi!

Even the flow rates are unlikely. Multiply rpm by 10 and the flow rate multiplies by 1.3? Maybe this is because the pump is so worn out after trying to develop 2000psi ;)

In reality land:

The pressure switch is set to about 140 psi and the pump is capable of delivering 160 max.

Normal ride height on any of the AS vehicles is about 70psi in the air bags depending upon load.

Link to comment
Share on other sites

I think you are getting ACE and SLS mixed up Si ;)

ACE is the hydraulic anti roll bar system, not the air springs, and the book does indeed say 135 bar for the ACE system. I guess the pump is a near enough constant flow type (a bit like a PAS pump or the Milemarker ZF74 pump) so that if you back off the throttle going in to the corner in an auto vehicle you don't suddenly lose all the ACE effort and find the door handles touching :)

Link to comment
Share on other sites

Hmm. I was trying to get some idea of the forces involved to see if the same thing could be done (crudely) at low(er) pressure with an air ram, but since the rams they use for ACE can't be more that 2" diameter, it seems not. Well, not without big travel and humongous leverage, anyway.

Link to comment
Share on other sites

If you did enough fiddling you could probably modify an air suspension system to pump up more on the outside of the corner? so you wouldn't need bars at all just adjust the spring pressures. I guess the problem with this idea is likely to be reaction speed, do a quick left-right and the second half of the corner is entered with the higher pressure spring on the inside which could be interesting :huh:

I just re-read your first post. How do you measure hydraulic pressure with a tape measure? :unsure::D:P;)

Link to comment
Share on other sites

I'm just playing with ideas for an active suspension with low(er) power consumption, which pretty much rules out anything holding the car up. Active damping and anti-roll appeal in this area, especially following mods which reduce the roll stiffness of the vehicle (3-link, slotted bushes, soft long springs etc).

Active anti-roll could also be used on the road as the Disco does, but also to improve sideslope performance and perhaps give benefits in crossaxles too. SimonR had full air suspension on his Ninety and it did all of the above but used prodigious quantities of air along the way. As a fag packet idea it looks like you sacrifice the height adjustability but lose most of the complexity too, and build in redundance along the way.

Tape measure - I was hoping someone would volunteer to measure the lengths and lever-arms on the Disco ACE system so I could put some numbers together. Everyone knows you can't use a tape measure to work out hydraulic pressure - you'd need a 'bar' for that :blush:

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...

Important Information

We use cookies to ensure you get the best experience. By using our website you agree to our Cookie Policy