V2Rocket

Not a fuel pump, first of all.

This all came to me last night at 1AM while doing more reading on water/meth injection. This would be for my supercharger project. I'm trying to find inexpensive solutions to that type of setup.

I tested a 944 windshield washer pump for flow and pressure output and with a small enough nozzle it hits about 40PSI and can hold that.

Now normally 40PSI of water pressure would not be enough to properly atomize in the manifold (not sure if I would do injection at each individual runner or pre-manifold) at about 10lbs boost. This is the reason why an FPR keeps fuel pressure about 2.5bar higher than manifold pressure (or vacuum for NA cars) especially under boost, to properly atomize the fuel.

Then I thought, could I use a FPR on the end of a rail made for the meth system? It would work the same way as the fuel FPR with a manifold signal and would maintain a pressure differential no matter what boost I was running.

The problem with this in my mind is that at 10psi boost the FPR would be making the rail pressure would be about 47PSI above atmosphere. If my pump can push about 40PSI would it be capable of pushing against a 47PSI regulator or would it die completely?

TurboTommy

Well, with your intentions the regulator would provide 47 psi over AMBIENT, but still only 37 psi of atomization pressure (minus boost).
Pumps, when they get close to their capacity, lose flow capability drastically to the point of not being able push anything through.
Those windshield washer pumps are way too weak; even if you were able to get 60 psi out of it (which is what you should have for water atomization), without dying, flow quantity will be very little. How much flow did you get with the 40 psi?
Get a shurflow pump.

V2Rocket

i figured. thanks

gt37vgt

one way to help the case is to use the blower pressure to help get more pressure differentail at the spray nossle ..
so you presuurise the tank with boos air and you spray the water into the the inlet of the blower .

the further you put the spray from the inlet valve the easier it is to get to work with a crude set up ....

2 washer pumps and 2 sprays inside the airr cleaner will work ...

not as good as a surflo but still will work ..

every water injection set up i have ever seen made of junk parts has been a sucess...

there are benifits to getting the good bits but you can make a system for next to nothing

V2Rocket

i have thought about that but the problem is that spraying before the blower would have a positive effect on cooling the rotors of the supercharger which in turn would cool the air a little bit but it would be nowhere near the amount of post-blower evaporative cooling. also i plan on intercooling my setup and injecting pre blower (and therefore pre intercooler) is a bad idea because water will condense inside my IC and i will lose major airflow

gt37vgt

research has shown that the longer you put the water in the system the better chance it has of evaporating and the better aniti knock effect it has its never done with cenfrical blowers or turbos as the droplets somtimes damage the compressor .. but on a roots set up it is the way to go ...
it will not condense out unless there is **** loads wich you won't get with a cheap or basic system ..

gt37vgt

And the rotors arn't going to suck the cooling away any thing you doo to the rotors you inturn do to the air ....
and in the chicken and egg way its the air heating the rotors so inject the water and you will be adressing the air heating and the rotors will not have heat to be sucked ....
there is no bearing heat or internal raidiating heat coming from the rotor's .
and the other thing is geting the water into the air stream and evaporated in more inportant than cooling the air it seems ..

CurtP

I'd say get the proper meth kit, but did you test a headlight washer pump? It's a high-pressure positive displacement pump that flows considerably more than the windshield pump.

V2Rocket

no, i dont have headlight washers..i assumed they were the same pump.

flow isnt really what im concerned about, i need pressure. like a 1GPM @ 70psi pump would be perfect lol i just dont want to spend $200 for a shurflo (but i will probably end up doing just that)

ehall

Spencer, remember that flow and pressure have a direct relationship. You can flow more, with less pressure or you can flow less with more pressure. The key is to find the optimum compromise for your application.

V2Rocket

of this i am aware..like i said flow isnt really that important, its pressure for atomization...and i need a low-flow, high pressure alcohol compatible pump (cheap fuel pump maybe?) for low cost lol

i wonder what the maximum operating pressure is of a 944 pump...if it can support like 400HP at 37-45psi regulated i wonder what its flow is like at 100psi..

gt37vgt

there are cheaper pumps around I have a caravan water supply 38 psi almost 1 GPM i think it can be modded for more pressure ...
it a diapram pump and pretty noisy. ... I wonder what the turbo water pump is like ..It has the flow I wonder about what kind of pressure it would make through a sprayer....
the way forward is to use the spray nossle that have a water and an air line then just spray it into the blower inlet I'm not sure about the pressure ratios i just know they are the way to go for superior atomisation.

V2Rocket

i found some good priced, higher pressure pumps so problem solved.
thanks everyone for the advice

gt37vgt

SHARE ,,..... Please.......

V2Rocket

pick one
http://www.systemacc.com/catalog/ind...7c4fd3a779d9bb

the one i will probably use is a 1.8GPM 100psi switched for $85

thats perfect.