Guest peter Posted April 1, 2012 Share Posted April 1, 2012 The o/p only asked what pressure to run at. But it doesn't take long before the usual suspects wade in with "I don't know why you feel you need air suspension Etc." Well.......he has it and that's that. He didn't ask for chapter and verse as to his motive for doing it or any other I know better than you comments. Link to comment Share on other sites More sharing options...
George Collings Posted April 1, 2012 Share Posted April 1, 2012 Sorry for boring you with technicalities Peter but surely one of the objects of this forum is the sharing of ideas with newbies and anyone who might find it interesting. I await the clarification from Airide with interest And will see if I can contact John Symonds who for many years sold Airide equipment. Link to comment Share on other sites More sharing options...
Mel B Posted April 1, 2012 Share Posted April 1, 2012 peter - 2012-04-01 9:37 PM The o/p only asked what pressure to run at. But it doesn't take long before the usual suspects wade in with "I don't know why you feel you need air suspension Etc." Well.......he has it and that's that. He didn't ask for chapter and verse as to his motive for doing it or any other I know better than you comments. Oi, stop being so grumpy Peter!!! :-| This is a 'conversation' and as such can 'wander' off in various tangents and with various views, this forum would be extremely boring if we were strictly made to answer only the specific questions asked and nothing else was 'allowed'. What did you're posting add to the subject in hand? Nothing, just you having a dig at people who are trying to help and offer other relevant advice on the subject too. >:-( Now, get to bed, have your hot milk and cuddle your teddy bear, there's a good boy! ;-) Link to comment Share on other sites More sharing options...
George Collings Posted April 1, 2012 Share Posted April 1, 2012 Further apologies Peter. I reserve my fundamental oomin right to be a boring old Fart. Having a second look at both the manufacturers information, Marcle think isolating the bags side for side is advisable for the same reason as I do but there is also sound logic in the Airide reasoning tocross couple that in the event of a suddden failure it is better that both bags deflate by the same amount to avoid sudden changes in handling. In practice due to the relativly small bore pipework compared with the volume of the bags any cross coupling would be heavily damped in sudden changes of direction temporily preserving the systems roll stiffnes. During prolonged cornering the anti roll effect would gradually be reduced as pressures in the bags equalised. The danger to the gauges is that someone couples up a really high pressure airline with the tap shut the air has nowhere to go and grossly exceeds the presure the gauges are intended to handle. Link to comment Share on other sites More sharing options...
Brian Kirby Posted April 1, 2012 Share Posted April 1, 2012 Derek Uzzell - 2012-03-31 2:48 PM George Collings - 2012-03-31 2:12 PM Brian, I have no details of how the braking system on your Transit deals with variation in rear axle loading but on most vehicles the ride hight is used to alter the front to rear braking bias. Using the air to maintain ride height can mislead any load sensing eqipment. Have you taken this into consideration. If not there is the possibility that your rear brakes are not providing the optimum braking effort. This could lead to increased breaking distance in an emergency stop or front brake fade on long descents. George I believe that all Transit Mk 6 and Mk 7 vehicles have ABS as standard. Certainly the 2004-onwards Transit chassis used by Hobby all have ABS. Unlike earlier non-ABS-equipped Transit models, there's no ride-height-based load-sensing feature to bias front/rear braking proportionate to rear-axle loading. In an emergency, whether you've got a bag of feathers or a half-tonne of gold bullion stored above the rear axle, you just stamp on the brakes and pray that the electronic magic of ABS will optimise your braking and save your bacon. Correct Derek, there is no ride height compensation on ours - though I'll admit I forgot about that when replying. So, good point George, thanks. The only times the ABS has kicked back, so far, have involved the front trying to lock - once quite spectacularly, on a wet day, across a newly painted pedestrian crossing, when someone pulled out of a turning just beyond it, and I had to brake going onto it. As soon as the brakes bit the wheels locked, so the ABS bit back. Virtually no braking at all until the front got to the other side of the crossing! Don't know who had the biggest fright as we vibrated onward, me, or the other driver. It works, but it isn't magic! :-D Link to comment Share on other sites More sharing options...
Derek Uzzell Posted April 2, 2012 Share Posted April 2, 2012 An air-bellows system in its basic form comes with no pressure-gauge, having a simple Schrader ‘tyre valve’ terminating the air-line leading to each bellows. The bellows are inflated individually and the user adjusts the pressure in each bellows via an ordinary tyre-pressure gauge. Where a system includes a gauge, there may be a single gauge and a pair of On/Off taps that can be employed to ‘read’ the pressure in the bellows individually or in the system as a whole. There can also be a pair of gauges, each of which reads the pressure of a single bellows. Logically, if an objective of fitting an air-bellows system to a motorhome is to combat excessive roll during cornering, the air-bellows should not be interconnected pneumatically. Interconnection negates the anti-roll value of the system, as, when cornering, air-pressure transferring from the bellows that’s under increasing load to the bellows that’s under decreasing load is the exact opposite of what's needed. The earlier comment from EMS indicates that, despite narrow-bore tubing being used, air pressure can transfer quite rapidly from side to side during cornering if the bellows are linked. While it might be Really Bad News if a genuine air-suspension system lost pressure, the systems being discussed here just provide assistance to conventional springing and I doubt very much if a single bellows losing pressure would make much difference to the way the vehicle handled. Whatever the case, if you want to address cornering roll, interconnection of the bellows is the wrong way to go. Link to comment Share on other sites More sharing options...
ferd Posted April 2, 2012 Author Share Posted April 2, 2012 Just taken the Hobby out for a drive around the country roads here in the Scottish Borders since the air suspension kit was fitted. What a difference in the handling, hardly any body roll, drives straight and true with no wallowing. Glad I've got it fitted and my garage would agree with your comments about interconnection. Thanks to all who have responded... most informative and helpful. Link to comment Share on other sites More sharing options...
Guest peter Posted April 2, 2012 Share Posted April 2, 2012 Thank god for that.Now Derek and co can go back into hibernation for a while. Oh I spoke too soon, I forgot there's an A Frame thread running. That should be entertaining. (lol) (lol) (lol) Link to comment Share on other sites More sharing options...
George Collings Posted April 2, 2012 Share Posted April 2, 2012 Peter, what A frame thread. Pull the other one Link to comment Share on other sites More sharing options...
Guest peter Posted April 2, 2012 Share Posted April 2, 2012 This one, but don't tell Derek and Brian. (lol) (lol) http://www.outandaboutlive.co.uk/forums/forums/thread-view.asp?tid=27093&posts=55 Link to comment Share on other sites More sharing options...
Derek Uzzell Posted April 3, 2012 Share Posted April 3, 2012 How can one trust the advice of a man unable to specify the manufacturer of his own motorhome correctly? Link to comment Share on other sites More sharing options...
pepe63xnotuse Posted April 3, 2012 Share Posted April 3, 2012 Just found these photos of our van pulling up our driveway,prior to having the air assistors fitted... (..'twas a bit tooo close for comfort... :-S ) Link to comment Share on other sites More sharing options...
Guest peter Posted April 3, 2012 Share Posted April 3, 2012 Derek Uzzell - 2012-04-03 9:49 AM How can one trust the advice of a man unable to specify the manufacturer of his own motorhome correctly?Well spotted Derek, I reckon you've had a word with some of your mates at MMM and got it changed. :D Link to comment Share on other sites More sharing options...
flicka Posted April 3, 2012 Share Posted April 3, 2012 Come on Peter, What's your secret ??? How did you get that one past the usual suspects for so long :D :D Link to comment Share on other sites More sharing options...
Guest peter Posted April 3, 2012 Share Posted April 3, 2012 Well.....Derek found it. How sad is that. Nothing better to do than scan everybodys profile. (lol) (lol) :D Link to comment Share on other sites More sharing options...
Perso710 Posted April 4, 2012 Share Posted April 4, 2012 I have a Perso 710 on a Alko Maxi chassis with trailing arm suspension which I feel is very soild. I usually drive unloaded with 50psi in the tyres. Would air suspension help my van or any suggestions. Ken Link to comment Share on other sites More sharing options...
Derek Uzzell Posted April 4, 2012 Share Posted April 4, 2012 peter - 2012-04-03 11:24 PM Well.....Derek found it. How sad is that. Nothing better to do than scan everybodys profile. (lol) (lol) :D No need to scan your profile, Peter - the stylish Matalan blue shirt just naturally attracts the eye. ;-) Link to comment Share on other sites More sharing options...
Derek Uzzell Posted April 4, 2012 Share Posted April 4, 2012 Perso710 - 2012-04-04 12:37 AM I have a Perso 710 on a Alko Maxi chassis with trailing arm suspension which I feel is very soild. I usually drive unloaded with 50psi in the tyres. Would air suspension help my van or any suggestions. Ken Welcome to the forum, Ken. Provided that you are happy with the way your Benimar Perseo 710 drives, rides and handles, and the vehicle shows no evidence of being down at the rear, I seriously doubt that adding 'air assistance' would be financially worthwhile. There is a difference between "air suspension" and "air assistance", with the former replacing conventional steel springs with air-bellows and the latter adding air-bellows to assist existing steel springs. Air suspension usually needs to be fitted when the vehicle is originally built, whereas air assistance can be retro-fitted later if the owner concludes that it will be beneficial. A motorhome normally has air assistance added either because it's plain the vehicle's existing springing needs help or the owner feels that adding an air-bellows system will improve the motorhome's on-road driving characteristics. In your case, as your Perseo is on a heavy-duty Al-Ko Maxi chassis, as you've rated the 'feel' of your motorhome's suspension as "very solid", as the tyre-pressures you are using are definitely not excessively high and you usually drive unloaded, it's hard to see how further firming up your motorhome's rear suspension (which is what adding an air-bellows system normally does) would be advantageous. If you did want to add air assistance, you'd be looking at around spending £700 minimum. For more information, GOOGLE-search using "Al-Ko air suspension" (omitting the quotes) as the search-term. Link to comment Share on other sites More sharing options...
EMS Posted April 4, 2012 Share Posted April 4, 2012 I have just looked back on the site and I see there has been a long discussion for Open/Closed valves. When the system was fitted we were told to keep the valves open, I thought this was strange so that is why I commented. This was based on my experience from many years ago I had an Austin 1300 that had hydrolastic suspension that was linked front to back not side to side. This gave virtually no body roll when cornering unlike a conventional suspension but when halting on a hill then the car tried to level itself, i.e. when uphill the front of the car dropped and the rear raised itself. this was corrected when driven froward again. So now I will shut the valves to see the effect. Link to comment Share on other sites More sharing options...
George Collings Posted April 5, 2012 Share Posted April 5, 2012 The raised tail when stopping on a hill with a hydroelastic suspension was initiated by the effect of braking on its trailing arm suspension. Going forward brake torque acting on the suspension arm tends to make the rear squat . Thats a good thing as it lowers the back end and reduces the weight being transferred foreward. Going backwards brake torque tends to lift the rear and due to the interconnection by the hydroelast.c pipes also lower the front. It was the 60s lots of rock but in this case less roll. Al ko rear suspension is also pure trailing arm and is available with full air suspension but without linkage to the front. Link to comment Share on other sites More sharing options...
Perso710 Posted April 6, 2012 Share Posted April 6, 2012 Many thanks Dereck for the welcome and the information. This is my first van and delighted with so I will keep the 'L' plates up even thought I am a silver surfer. Regards Ken Link to comment Share on other sites More sharing options...
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