Jan. 7, 2004 - Doing meth..(the injection kind, not the controlled substance kind)

Since our last visit, I've installed an Aquamist 2d water injection system. I'd almost classify this a "must-have" for a supercharged BMW that has to run 91 octane gas.

While power with the supercharger was great, it did get heat soaked after awhile. This caused a noticeable drop in power (but the car was still MUCH quicker heat soaked that it was without the blower).

The problem with Vortech supercharger kits on an E36 is that there's just not much room to install a front mount intercooler, and the kit that is available is over $2000.

RMS makes an air to water aftercooler that is much more compact, but it's also very pricy, over $2000.

So, if you want charge cooling at a reasonable price, that leaves water injection. For around $400 you can get the basic Aquamist setup, for a bit more you can get the more tunable 2d setup.

I lucked out and got a great deal on a used 2d setup from MitchP, a Bimmerforums member, and installed it over the weekend.

First off, the install wasn't as easy as I had assumed. I'm picky about my engine bay, so I wanted a very clean and very unobtrusive installation. This meant getting a bit funky with where to place the pump and how to route the hoses and wiring.

I ended up placing the pump behind my relocated charcoal canister (look at my SC install picture, the canister is the horizontal can near the passenger firewall), along with the relay and pressure manifold.

The used kit came with a baby blue accumulator that just looked awful in my mostly black/CF/aluminum engine bay. Luckily, Jim Powell had some magic paint remover that stripped it down to the bare aluminum in a matter of minutes, and a few coats of primer and satin black had it looking good enough to go on the car.

Once I had the big hardware mounted, I went on to modify my windshield washer reservoir to serve double duty, supplying water to the wipers and the Aquamist system. The stock tank is 2.5 L, and with aggressive driving and early spraying, it might not be large enough for prolonged use.

So, I had ordered a 5 liter tank, which is used on E36's with headlight washers. I plugged the hole where the headlight washer pump goes, drilled a new hole in the bottom for the feed line, installed the fitting, gooped on liberal amounts of silicon, and reconnected the original washer pump and tank sensor. I ran the feed line along the right fender, same route the windshield washer line takes, and then back past the battery tray, where it connected to the Aquamist pump.

The feed section is white tubing, I plan on switching that to black tubing in the future so it blends in better.

Then I had to drill and tap a hole in the supercharger kit's discharge tube to accept the Aquamist nozzle. This threw us a curve because it calls for an M8x.75 tap. That's an unusual size, and nobody locally had one. I ended up using an M8x1.0, which has slightly coarser threads, but it works fine as long as I don't plan on taking the nozzle out frequently.

Water and power lines were ran from the battery tray area to the fuse box area, sneaking them under the cowl wiring loom. There's a 3" long silver high speed valve that's actuated by the Aquamist controller that I mounted near the brake booster area.

Then I had to tee off a vacuum line to the boost sensing pressure switch. No big deal, I'd already tee'd a line for the supercharger bypass valve, so I just tee'd again there. Mounted the pressure switch low on the inside of the driver's fender bulge, nice and out of the way.

Last but not least, I had to mount the FIA2 fuel injector amplifier/WI controller. This I double-sticked onto the side of the fuse box.

Wiring was fun, tapped the line on the fusebox for 12+, tapped into the fuel pump fuse for switched power, and grounded off one of the chassis bolts near the Aquamist pump.

Then I had to tap into the fuel injector lines (the 2d system sprays water based on the fuel injector duty cycle), run that wiring back to the FIA2, run another set of wires to the high speed valve, and two more to the pressure switch.

Once all that was done I put all the wires in flex loom to further hide them, and connected the water line to the nozzle.

Total time was hard to tell, since I spread the job over three days due to working Saturday and going to a local BMW meet on Sunday, and just plain procrastination.

After it was all installed and running, I wished I hadn't taken so long. There's a noticeable improvement in power even when the car is cold. This is because water injection reduces or eliminates detonation, and this allows the computer to keep timing advanced to make more power.

And the power stays constant. Running the living piss out of the car for half an hour used to be a guarantee for heat soak and power loss. Not now. Car pulls strong all the time, there's not even a hint of detonation, and to me it feels like the car is happier. It feels much smoother at higher RPM's, and even sounds a bit different. I have the system set to start spraying water at 3.5 PSI, which is right around 4k RPM. I may back it off a little once I get it on a dyno so I can fine tune it.

If you're thinking about forced induction, be sure to add an Aquamist system to your list, it's well worth the money.

Next on the list? I have a smaller supercharger pulley sitting here, good for about 1 to 1.5 more pounds of boost, which translates into somewhere between 15-30 more horsepower. With the Aquamist I'm less worried about running it, and plan on installing it this weekend.

After that, she goes on the dyno to see where I'm at.