There is a northern tools store now open in Tampa. They carry 60PSI 1.8PH Shurflo Pumps, for about $60.

You'll see people selling 60,100,150PSI pumps for different prices, but they are virtually the same.

There is a pressure switch on the top that determines the PSI of the pump. I learnt this a couple years ago when I traded up for a 100PSI pump and paid over $100 only to find out the switch was the difference.
These days, I have bypassed the switch and am running well over the advertised 100PSI mark.

Anyway, if you're looking for a simple WI kit, this pump is a good starting point. You can always bypass the switch for higher pressure, or swap out the switch for a higher one, while paying less.

A basic kit can be done for :
$60 pump
$15 pressure switch
$15-20 check valve or $30 for a solenoid
$5 nozzle.
Less than $10 in 300PSI nylon tubing at Home Depot
Couple $'s on wires.

I've been running my kit for about 2 years now, no problems. I started with a basic home made kit, spent uneeded $ on a 100 PSI pump, and eventually purchased a progressive controller (PC) in my quest to hold HOM on Stage3.

I've learnt that the PC is nice, but not necessary to see results from WI.

 

how much does water injection actually help? (IE how does it affect a/f and hp/tq)

 

I have been interested in this for some time, WI and CO2 sprayers seem to help with timing on our cars. I've just always been afraid that the WI will give my car more advanced timing than it needs possibly causing knock, can this happen?

 

There is no set rule. What I have seen/logged on a stock turbo running 18-20PSI, is that each degree of Charge Temp drop resulted in 1hp increase.
This was with a IC cooler (co2 type).

The same data was backed up by the intercooler shootout results posted on srtforums...basically 1hp per degree drop.

So basically, the gains will depend on how bad your charge air temp is. Things go down hill REAL QUICK with temps over 100deg.

 

Remember, if there is knock...the computer will dump fuel, pull boost, and retartd timing

 

Cool I figured that would be the case just wasn't sure

 

what about alcohol injection? I'm assuming it will work for that as well?

 

Not 100% sure on the seals in the pump, but I've run 50/50 meth water without any damage so far.
Check SRTforums.com...under devilsown vendo section. He has excellent factual info about these pumps.

 

alcohol injection should work fine with these pumps.

 

+1 ^^^

You need something to tune with to get a really good gain from W/I... I sold my W/I b/c I didn't have the $$$ to buy an AFC, rpm adaptor, and dyno time to tune it...