Alright, so I’ve scoured this site as well as others and I’m trying to wrap my head around the info I’m finding. I have a Pressure Pro 5.5 2500 belt drive machine… draw test shows a little above 5.5 gpm (closer to 5.75-5.80, definitely under 6… 55 gallon drum I was using was hard to read). I’m using 200 feet (2 - 100 foot sections) of 3/8" hose, 2 foot whip line from pump to a cox reel, and the M5DS at the end of a suttner gun (rated at 12 gpm I believe?) attached via a DN10 ball valve with mosmatic swivel.
Originally I bought a 2.3mm injector because thats what the descriptions online led me to believe I needed… pulled around 13 or 14:1 so roughly .83-.89 down streaming straight 12.5% (if my maths correct). Did some research since I was hoping for a little more draw… found out you guys are downsizing the injectors so ordered a 2.1mm… pretty much the exact same draw and ratios as the 2.3mm. Then I read some of @Barry1 past posts, since I believe we are running the same or similar machines (gx390 and GP 5535 though I think they are using gear drive?) and testings of injectors aligns with what I’ve been finding as well… so my questions are as followed:
If guys that use 8+ gpm machines are running 2.1mm (sometimes 1.8mm) injectors should I/can I go even smaller then that? It would seem that having a lower flowing machine would mean I could get away with a smaller orifice without the restriction being as noticeable… but I don’t know the physics/engineering side of it.
The smallest injector size I see talked about is the 1.8mm, but it looks like GP makes some stainless steel injectors (for carwashes?) in the 1.45mm and 1.6mm range. Would these be too restrictive for my machine? They have plastic barbs for the intake is that a weak point? They are almost 3x as much cost wise, but if stainless steel makes them last longer then they may be worth it… Here are the ones I’m talking about.
I have also seen the check valve modification, though have heard mixed reviews on it’s claims, and figure that if it’s worth doing then going stainless steel for the injector wouldn’t be a bad idea… and if the carwash injectors work that would get rid of the plastic barb if it’s a weak point. Has anyone gone this route before?
Is it even possible to DS chems for concrete pre/post treating with my machine? I would need closer to 2-3%? which seems like a pipe dream, even getting 1.25% seems like a stretch at this point… any other tips or advice on what could help this (besides using an x-jet, pump sprayer, or 12V system for applications)?
I was using a 2.1 with my 8gpm, if you get anywhere near 1% strength you’re doing really well. That’s why it’s imperative to maintain a fresh supply of SH, washing a house with 4 month old bleach is no fun.
You can post treat concrete with DS if you’re just left with light stripes, but I’ve had some lichen roots on a few driveways that need 3%.
I try to get the freshest SH I can… but I’m still small time so only buying it by the gallon if/when a job comes around.
I suppose I should be content with the percentages I’m getting, but just wanted to make sure I wasn’t missing something obvious.
I may try to build a check valve on a 1.6mm or smaller just to see what it could pull and how it impacts performance.
I have an x-jet that I’ve used to get 3ish% before but it just seems cumbersome compared to downstreaming at this point so I was hoping to find an alternative to help my workflow.
$200!!! Claims a 4 gpm pulls 5.4:1 and a 8.5 gpm pulls 13:1… so guestimating for a 5.5 gpm probably around 9-10:1… which isnt bad, but the price point is high and the orifice size is the same as a 1.8 mm and 2.1 mm injector so I’m skeptical of the claim. Anyways I ordered a 1.45mm (.055) and 1.6mm (.062) injector along with a couple check valves to test out.
It’s on par with the SSS. I’m sure you know by now it does it without a spring and soft o-ring main seal for more reliability and the Gen 2 is where it’s at! 4 gpm 5.4:1, 5.5 gpm 7:1, 8.5 gpm 13:1
You used the word claims twice so I’d like to just say they are not, these are exact dilution rates you will see. You will never see exact dilution ratios posted up on any other injector. Only claims of percentages like 20% or back when the SSS was claiming 33%. Dilution ratios are direct results!
You’re right to be skeptical. There’s a ton of snake oil in this industry and it’s getting worse every year.
The PW Gadgets injectors are no gimmick. I have one on the 8.5 and one on a 5.5 and been running them all summer long with absolutely zero issues. The draw rates claimed are accurate. There’s videos on here with test results showing that as well.
As far as price goes, $200 is a drop in the bucket in the grand scheme of things and I can assure you I’ve spent well over that on GP injectors through the years and I’ve had new GP injectors go bad within a week. Others have had bad ones right out of the box. Once you’re busy most days, reliability becomes much more important than cost. Sure, you can keep spares but you’re still dealing with downtime to R&R that injector.
@Anton_C_K The problem you’ll find with under sizing your injector nozzle anymore than say .070" on a 5.5 will be that you don’t have the beans on a GX390 to overcome the restriction. Get your RPM measured and you’ll see that pump start to crawl. Besides that’s its a long hard life running that lil engine flat out.
Correct, I used and stand by the term “claims”. This is the first I’ve heard about/seen this product. From the quick google search I did on it, the only info that comes up, is from the company (which I believe you have vested interest in?). Obviously as you pointed out, manufactures have been claiming whatever numbers they want… so before I state things matter-of-factly without having first hand experience or looking into it further, claims it is.
It’s spinning at 3600 on the nose, but does surge down to 3540 at times… that is hopefully the next upgrade over winter. I’ve been debating keeping the machine and just putting on a 16-18hp engine or selling and going 8-10gpm as I’m doing more flatwork then anything else at this point.
After tinkering and swapping around orifice and check valves I finally got a setup that will pull 1 gallon of soap and 10 water (11 gallons total) so I’m happy with that… only downside is I did a poor job of keeping track of what parts/sizes ended up on the final build. One day I’ll sort through the parts box and see whats missing out of it.
