Trying to find the perfect flow

Supplies & Equipment
1

Hello all!

I am starting up a mobile car wash, and I am struggling to find the right machine that will give me the flow I am looking for. In a perfect world I would like something:

  1. 4-5 gpm
  2. ~2000psi, wide nozzle
  3. Relatively quiet
  4. Must be able to pull from a tank with ~150ft hose

I purchased a 6 gpm 12v pump, but I dont think it has quite the guts that I am looking for.

The closest I have seen to what I am looking for is someone using a 5.6 gpm 2500 psi belt drive, while downstreaming. Maybe I could set the machine up with a chem injector and just pull water through to sort of slow down the flow?

Thank you all for your help.

2

I am overthinking it.

I just need a bigger nozzle. Something like a 7.5 would give me ~2000 psi with a 5.5 gpm right?

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3

Yes you can always change nozzles to lower pressure. But if you’re downstreaming just make sure you’re not still drawing soap.

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4

You can always put a small ball valve on your chem line to shut soap off or drop your line in a bucket of water…(if your still pulling soap with larger nozzle)

5

I dont know a lot about pressure washers on the level the guys on this forum use but I know a LOT about car detailing and use of pressure in that process.

I wouldnt put 2000psi on one of my cars. But like has already been said, you can just change the nozzle to lower psi.

I use a Kranzle K1122TST. Its a high end electric that shuts down when you release the trigger. So no worries about water overheating in the pump which could happen depending on your wash process. They also make a wall/floor mount version. Both available at obsessed garage. They both put out just over 2gpm at only around 1400psi at the pump. It ends up being around 1100psi at the tip supplied in the obsessed garage kits. And it is perfect for washing cars. I can hold my hand in the stream at the end of the lance. But it still blasts away dirt from the wheel wells etc when needed. The 2.1gpm is great when using foam cannons and for general rinsing. (I also use a deionizing filter to clean the water for final rinse so no water spots)

Are you using a foam cannon?

6

Thanks for all the replies!

A distinction I should have made is that it will be a mobile car wash, not detailing. It will be out in the CA desert, and I do not think the community will support a detailing company, nor do I want to spend 3 hours on a car with a polisher.

So with that said I am looking to do high volume, quick, and relatively low price car washes. And I need a machine that can match those demands.

I’ve kept my RODI set up from my window cleaning days, which will help speed up the process( i.e. let nature do the drying)

I know that machine is very popular with car guys. One hangup for me would be having to buy a generator, which would put it much higher price wise than a gas machine. I could see how 2000 psi might be a little much. Maybe I’ll aim for 1500-1800. I would obviously use a wide tip and stay back from the car a ways.

No foam cannon. I think I’ll use a brush on a pole and a surfactant when needed.

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7

You can buy any 4GPM 4K machine and like others have said - use a larger nozzle.

For example, you will get a white tip with your pressure washer, the size will be 040 (that’s the orifice size to deliver 4000psi for that machine).

Simply purchase the white nozzle for a 5.5GPM machine or larger. You will get a nice fan with the white tip and the pressure drops more and more with the larger orifice :slight_smile: