3000 vs 4000 psi

currently running a couple 4 gpm 4000 psi machines.
Business has been booming this year compared to last year so I'm wanting to grab 1 8 gpm machine and not sure whether I wanna get 3000 or 3500 psi.
will running 8 gpm 3000 psi along side 4 gpm 4000 psi leave a noticeable difference as far as how clean it looks?
I'm just gonna get 1 8 gpm machine for now.
 
ok, thanks Ty.
I wasn't sure if spending an extra $350 for an 8gpm 3500 psi machine would've made a difference or not.
Or what do you think?
I mean I'd already be looking at dropping $3k+ for the 3000 psi
 
It would not hurt to have the extra psi in case you are running long lengths of hose, you lose about 300psi for every 100' of 3/8" hose when running 8gpm, if you use the 1/2" hose then you only lose about 45psi for every 100' of hose. With 5.5gpm, you lose about 135psi for every 100' of 3/8" hose.
 
I think PSI is over rated... Its all about GPM. But you definitely want to stay in 3000. 3000PSI @ 8GPM is a great machine.

You're right Ty. A couple if years ago I talked on the phone with an R&D guy at Spray Systems. He told me that if you double the PSI (say 2,000 to 4,000) the cleaning power increases by about 40%. But if you double the GPM the cleaning power increases by 100%.

The Cleaning Unit thing (PSI X GPM) that the manufacturers use to sell consumer machines is bunk.
 
ok, thanks Ty.
I wasn't sure if spending an extra $350 for an 8gpm 3500 psi machine would've made a difference or not.
Or what do you think?
I mean I'd already be looking at dropping $3k+ for the 3000 psi

I agree with Guy too and the other responses. If its only $350 more then get the PSI. But I was just saying in general PSI is not as important as everyone makes it sound when it comes to concrete cleaning anyway. But Guy is right when you put on 200 ft of hose you will be running 2800. But still 2800 at 8gpm will get the job done. So I guess it comes down to how important $350 is to you. If it was me I would spend the extra $350. But I also drive a Lariat because I need the leather interior. Again PSI is over rated! haha
 
I'm not sure where these psi drop calculations are coming from. I just put a gauge on my machine yesterday. It was 2500 with 100 feet of hose and it was 2400 with 200 feet. It is a 5.5 gpm, 2500 psi , 3/8 hose. That being said, concrete cleaning is much better with my 5.5/ 2500 psi machine than with my 4 gpm, 3500 or 4.6 gpm, 3000 machine. If you plan on doing mainly residential, then 3000 psi is all you will ever need. If you plan on adding commercial then go for the 3500.
 
Those are calculations from the manufacturers.

Are you checking the pressure at the pump or end of the hose?
 
I'd get the psi. You'll always come across a job when you wish you had it. I did yesterday. I'm running 4gpm @ 3000psi.

Hose Friction Loss.jpg

"The cost is only an expense if you don't use it to pay for itself." - CL Scott, Intelligent Innovator
 
yea might as well spend the extra $350.
Thanks guys
 
i had two 4gpm 4000 machines on my rig... i replaced the older one with a 8GPM .. 3000 psi unit.......... Whoa....... I won't even touch the 4GPM anymore... If you go with an 8......... get a Big Guy too...... It will be the best investment to go with it.... It friggin FLIES!!!!

yea I'm super excited.
What do you have on your big guy, 2 nozzle or 4?
I'm currently running a couple whirlaways and one of them is 24" with 3 bar.
pretty excited to see that sucker run at its full potential
 
I'm not sure where these psi drop calculations are coming from. I just put a gauge on my machine yesterday. It was 2500 with 100 feet of hose and it was 2400 with 200 feet. It is a 5.5 gpm, 2500 psi , 3/8 hose. That being said, concrete cleaning is much better with my 5.5/ 2500 psi machine than with my 4 gpm, 3500 or 4.6 gpm, 3000 machine. If you plan on doing mainly residential, then 3000 psi is all you will ever need. If you plan on adding commercial then go for the 3500.

There are a few factors in psi drop. Testing with a downstream injector in place will also cause a psi & flow drop. Results can vary a couple of hundred psi +\- depending on equipment.
 
yea I'm super excited.
What do you have on your big guy, 2 nozzle or 4?
I'm currently running a couple whirlaways and one of them is 24" with 3 bar.
pretty excited to see that sucker run at its full potential
You are using a 24" surface cleaner with a 4 gpm machine? Did it work decent?
I am at 5.5 and was wanting to try a whisper wash aqua pro 24 " .

Wondering if anybody has any insight on this.
 
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