Thread: Polyair with a differance, opinions please

Originally Posted by joel0407

I recieved a call from Polyair this afternoon as I had asked a question through the "Contact us" on their web page.

The answer was: Poly Air, in coil air bags cant be used to lift a vehcile because they grip the insides of the springs and cant expand up. He gave me an example of a person he had sold a set to, installed them and then measured the rear of his vehicle with the trailer on, inflated the poly air bags and found no change in height so requested a refund. Poly Air being the good guys they are refund the guy even though he wasn't following the instuctions.

Poly Air said that should have the guy driven up the road a little the bags would have moved with the spring movement and settled heigher. This all makes sense to me now.

Next problem he suggested is the SLS system can provide far more pressure then the Poly Air bags can handle and left to it's own devices it could just pop a bag. This also made sense as the SLS system would realise the vehicle is sitting too low with under rated springs and start providing pressure. Intead of the vehicle rising, it would simply push the bags out against the spring as stated above, then it would continue to apply pressure until the pressure was so high it pushed an end out of a bag and pop.

Anyway that idea is out the window now and it looks like once I'm settled in Darwin, I'll be restoring the LR SLS the way it was designed to be and maybe with a new set on shocks all the way around.

Happy Days.

Thanks for your help and ideas fellas.

My coil-rites can have 200kg from my boat on them, sag and then as I pump them up they lift the back end. I will have to stop that. ..done it for 3 years but will have to air up first. I know by now they like 20 pound. Actuality 15 pd makes it handle like a go cart without a load...

Cheers

Originally Posted by wardy1

OMG! This thread has become sooo complicated!

Really not sure why sometimes we get bogged down with lots of theory when there are manufacturers specs which set out the proper usage of a product. The pro's and con's of SLS notwithstanding. This member DOESN'T currently have SLS but DOES have a very good system in place to keep his vehicle pretty level (providing that the pressure is lifted to prior to the load)and articulate over most surfaces...... where's the problem?

Fair go mate.

I only bought this vehicle a week ago and I dont have any manual or anything for the Poly Airs. That's why I'm here asking.

I thought it made perfect sense to combine the 2 (SLS and coils). The only thing I misses was that the Poly Airs cant lift the vehicle. I thought I could have the ride and convenince of Air with the reliabilty of Coils.

Through the discussion here I learnt I cant. No need to stress.

As I dont require the back of my Disco to carry much weight so the Poly Airs are pretty useless for me. They wont raise or lower my vehicle, I dont get the more comfortable ride I'm told air gives so I will be just running around with them at minimal pressure. I might as well take them out and sell them.

All the rest of the gear for the original air bags is still there so I might as well take out the springs and sell them with the Poly Airs. Add a few bucks and buy what I need to get the original bags going with a few spares as a fail safe.

Happy Days.

Originally Posted by joel0407

Fair go mate.

I only bought this vehicle a week ago and I dont have any manual or anything for the Poly Airs. That's why I'm here asking.

I thought it made perfect sense to combine the 2 (SLS and coils). The only thing I misses was that the Poly Airs cant lift the vehicle. I thought I could have the ride and convenince of Air with the reliabilty of Coils.

Through the discussion here I learnt I cant. No need to stress.

As I dont require the back of my Disco to carry much weight so the Poly Airs are pretty useless for me. They wont raise or lower my vehicle, I dont get the more comfortable ride I'm told air gives so I will be just running around with them at minimal pressure. I might as well take them out and sell them.

All the rest of the gear for the original air bags is still there so I might as well take out the springs and sell them with the Poly Airs. Add a few bucks and buy what I need to get the original bags going with a few spares as a fail safe.

Happy Days.

Poly and such will raise the vehicle matey. It will make the ride very firm and the wheel travel poor, but it will raise the vehicle, especially if the springs are a bit tired. If you stick say 25 pound in and dump a load on the back it will not sag. I love the coils with coil helpers - ie aftermarket air bags. The coiler Disco's handled very well from the factory. Many 4wd mags gave them a better ride/handling compromise wrap than the air suspended vehicles. Just keep the bags and springs and go hard!!

Cheers

Originally Posted by ozscott

Poly and such will raise the vehicle matey. It will make the ride very firm and the wheel travel poor, but it will raise the vehicle, especially if the springs are a bit tired. If you stick say 25 pound in and dump a load on the back it will not sag. I love the coils with coil helpers - ie aftermarket air bags. The coiler Disco's handled very well from the factory. Many 4wd mags gave them a better ride/handling compromise wrap than the air suspended vehicles. Just keep the bags and springs and go hard!!

Cheers

Are you sure some people aren't confusing "raising the vehicle" and "preventing it sagging under load"?

There is a difference.

Originally Posted by vnx205

Are you sure some people aren't confusing "raising the vehicle" and "preventing it sagging under load"?

There is a difference.

Mine do raise the vehicle unladen over and above the spring height - cant say by how much, but at a guess 1cm, but ride is compromised. Mainly though, you are right, they are to present sag and to throw some (not all of it taken off by the load - for that load bars would be used) of the weight back towards the front

Cheers

Originally Posted by vnx205

Are you sure some people aren't confusing "raising the vehicle" and "preventing it sagging under load"?

There is a difference.

Originally Posted by ozscott

Mine do raise the vehicle unladen over and above the spring height - cant say by how much, but at a guess 1cm, but ride is compromised. Mainly though, you are right, they are to present sag and to throw some (not all of it taken off by the load - for that load bars would be used) of the weight back towards the front

Cheers

That is right, but it isn't quite the distinction I was trying to make. I would expect that if they were pumped up, that the vehicle would sit a bit higher when unladen. I believe that mine sits a bit higher than standard when I take the camper off the back until I drop the pressure down to about 5psi.

What they don't do well and what the manufacturers don't recommend is putting a load in the vehicle and then pumping the air bags up to try to raise it back to its unladen height. The important difference is when they are pumped up; ie before, not after the load is added.

I know that is only repeating what has already been said.

Sorry for a quick detour of the thread.
vnx205 , what weight is your camper packed/ full and what pressure do you run in the bags with the camper on?

Cheers

The camper is about 360kg empty. So if I add 80 litres of water in the tank, a 9kg gas bottle, about 20 kg for food and about the same for clothes etc, the total is probably getting close to 500kg.

When I fitted them, I put 20 psi in them and that seemed to put my high beam headlights back down about where they should be. It also gave me enough support to maintain the speed I wanted going over the eco drains on the fire trails on the way into Bendethera Valley without bottoming.

Since it seemed to be about right, I must confess I haven't taken careful measurements or experimented with different pressures. So every time I put the camper on, I pump them up to 20 psi. (Before I put the camper on obviously. )