Dissatisfied with the speed of a single pump, I have upgraded and bought another VIAIR 400C. These on board systems are all pretty small, mostly around 2.5 cfm which isn't much. The 400C gives 2.54 cm at 0 psi. In other words when not under load. Fine for an air blow gun or something, but as with all these things you need to look at the delivery as the pressure ramps up. It's actually just like electricity really. And, just as with cable, the bigger the pipe the more air flows down it. Pressure on these pumps (150 psi) is pretty good so there's plenty of push.
What I have done is run each pump into the tank on a separate line. The standard airline is 6mm OD 4mm ID. So this would double to 8mm. But not content with that, I have managed to open this out to 10mm OD 7mm ID. I never timed it with 6mm and one pump, but the 2.5 gallon tank now fills in 1 m 15 sec. That's pretty fast. The true test is to fill a tyre. I took the valve stem out and flattened a tyre completely, on the vehicle. These are 285.75.16 (33") so quite some volume in there.
This is what happened. From a full tank, I was at 20 psi in 60 seconds. I let the pump run for a minute and opened the chuck again and in another 60 seconds I was at 40 psi. So 3 mins to 40 psi from zero. Of course I still had air in the tank when I stopped, so it could have been faster. Twiddling around, I felt that with the tank empty, there was clearly more straight through air delivery then with the original set up. Well so there should be really. But the tank tends to act as an accumulator and you don't get out what you put in as the resistance in the air nozzles, blow guns etc tends to back up and pressure in the tank starts to build sapping the flow at the end.
What I am contemplating now is upgrading the delivery side of the tank to the pcl couplings to 7mm as well. The real issue was getting the tank to fill more quickly rather than getting the air out of it faster, but hey, why not go for both?
The tank gives you that flexibility to do something else whilst the compressor is still running, where without it, you need to stop the pump or chance busting something. Many are not designed to run with back pressure for very long.
Well look, it keeps me happy and off the drugs.
Here's the pumps just on a board at the moment. I have to build in the drawer system first so that I can put them behind the middle seats. Until then they'll do like this. Got proper cable to them and a nice big relay. I will but a switch in line too so that I can knock the pumps off when I don't need them. They tend to tick in and out as the air gradually leaks which of course does drain the battery.
Chris
What I have done is run each pump into the tank on a separate line. The standard airline is 6mm OD 4mm ID. So this would double to 8mm. But not content with that, I have managed to open this out to 10mm OD 7mm ID. I never timed it with 6mm and one pump, but the 2.5 gallon tank now fills in 1 m 15 sec. That's pretty fast. The true test is to fill a tyre. I took the valve stem out and flattened a tyre completely, on the vehicle. These are 285.75.16 (33") so quite some volume in there.
This is what happened. From a full tank, I was at 20 psi in 60 seconds. I let the pump run for a minute and opened the chuck again and in another 60 seconds I was at 40 psi. So 3 mins to 40 psi from zero. Of course I still had air in the tank when I stopped, so it could have been faster. Twiddling around, I felt that with the tank empty, there was clearly more straight through air delivery then with the original set up. Well so there should be really. But the tank tends to act as an accumulator and you don't get out what you put in as the resistance in the air nozzles, blow guns etc tends to back up and pressure in the tank starts to build sapping the flow at the end.
What I am contemplating now is upgrading the delivery side of the tank to the pcl couplings to 7mm as well. The real issue was getting the tank to fill more quickly rather than getting the air out of it faster, but hey, why not go for both?
The tank gives you that flexibility to do something else whilst the compressor is still running, where without it, you need to stop the pump or chance busting something. Many are not designed to run with back pressure for very long.
Well look, it keeps me happy and off the drugs.
Here's the pumps just on a board at the moment. I have to build in the drawer system first so that I can put them behind the middle seats. Until then they'll do like this. Got proper cable to them and a nice big relay. I will but a switch in line too so that I can knock the pumps off when I don't need them. They tend to tick in and out as the air gradually leaks which of course does drain the battery.
Chris
