Aquamist HFS-3 Install
 

After two months, I finally finished the install on my system. I fired it up, made some runs, and I'm happy to report that the car runs just like it did beforehand (try explaining to the wife that after two months and a pile of money things haven't changed). I'm running windshield washer fluid, primarily because I live in Michigan, and I can't predict when the temps will drop below freezing.

I ran all braided stainless teflon lines or hard lines, and I'm injecting directly into the primary runners. I selected those over the secondaries because of concern over ingesting fluid into the brake booster that taps into the secondaries. I'm scaling IDC off the secondary injectors, and the system starts spraying at about 5 PSI, which seems like a good point.

The tank is a 5 gal stainless dune buggy fuel tank. I welded a mikshake cup to the bottom to act as an anti-surge sump, and it all runs through an AEM filter. I used nylon hose as a sight gauge.

I mounted the fast acting valve and flow sensor in the plenum, since that location put them close to the nozzles but away from engine bay heat.

Currently at 9 PSI, planning to increase gradually to 15.

Nice line bending.

I wonder why you chose to inject into the primary runners instead of just in the intake before the throttle body. I thought the purpose was to allow time for the water to cool down the intake charge. It has less time to cool if it is that close to the intake ports.

Also, I have the HFS 3 as well and love it:icon_tup:.


John

There are many posts about injection location -- take a browse. I did it for three reasons:
1. To ensure even distribution between rotor under all conditions. When one nozzle is used, one rotor may get less volume.
2. To avoid puddling and caking of the WWF. There's one member who found a large area of caked blue crust just before his throttlebody.
3. I have a big intercooler that seems to do a good job of keeping IATs low, so this location seemed like a better choice.

I agree that the runner location would be preferable. It's the same reason why electronic fuel injection has superior mixture formation and distribution versus a carburetor. On a carb you have the mixture flowing through the whole length of the intake manifold, and thus more subjected to pulsation effects, wall wetting, temperatures differences, etc. The same could be said about injecting water/methanol before the throttlebody.

Of course you can still make pre-TB injection work, just like you can make a carb work. On a pulsewidth-modulated system like the HFS-3 though individual runner injection takes full advantage of the system's features.