TrentO

I had meant to write this up a while back, but getting the car back together after the Edmonton Indy event sidelined me for most of the fall. I picked up an HFS-3 system from Howerton Engineering ( http://howertonengineering.com ), who got me outfitted with the HFS-3 and a non-slosh tank earlier in the season last year. you can see the tank here: www.rxracing.com

I picked the HFS-3 as my AI of choice due to the failsafe system and the fuel-based PWM injection. After all my research, the Aquamist looked to offer the most accurate metering and the best fail safe option on the market. Digging through all the threads here and on the Grand National site really made me settle on the Aquamist.

I managed to install in under a day and following the supplied instructions everything went quite well. I deviated from the recommended install by only using the input from the secondary injectors instead of using a summer module to get the input from both sets. As this is a race car, the majority of time I'm either at WOT or idle, so I felt the simplification would work just fine.

In talking with Jeff @ Howerton and using his calculator (which is on his site) we settled in on rate of 400cc of water for the jetting (as it is a road course car, we aren't allowed to use methanol). The dry testing of placing the jet on the windscreen turned out to be an excellent method for judging how much flow was coming through the system. We just ran the car at the track with the injector under my single windshield wiper.

My previous efforts in the one hour Indy race I limited the boost to 14 lbs (about 400 rwhp). I kept the boost low to ensure my car could manage the heat load of a full hour of very intense wheel to wheel racing. This year my plan was to use the Aquamist to further manage the heat load and enable me to run higher boost settings. I have a two stage electronic boost controller which applies pressure to the back of the wastegate, so I basically have three settings, spring, setting one and setting two.

For the Indy I left the stock boost at 14 lbs, setting one at 18 lbs and setting two at 21 lbs. In pre-indy testing at my local time attack track (I hold the lap record at 1:01.9, A new ZR-1 was a 1:04) the 18lbs setting felt amazingly fast and the 21 lbs setting was causing some wheelspin entering the straights. I decided for the Indy to run the 18lbs setting, with 21 lbs held in reserve for a "Push to Pass" option if the need was there.

The first day of the Indy was a disaster. We had good weather the previous day to unload, but the first day of the event was filled with rain. The Indy guys and Indy Lights guys declined to run. I borrowed a set of Yokohama street tires to just get a few laps in, as my normal slicks weren't going to cut it. The track featured a high speed "chute" after the first corner, which in the dry you would hit at around 100 mph. In the wet, it had about and inch of standing water. Between the lack of traction and the fogging inside the car, the practice fell down to me driving grandpa laps. I was in the high 20's position wise in a 40+ car field at this point.

The qualifying session was the next day and the track had dried quite well. I ran the first few laps slow, building speed as my comfort with the track increased. Just as I started to feel like I understood the track, a honda civic blew the bottom of his gearbox all over the track. In those few laps I moved up to sixth overall in lap times. The power level of the car was pretty awesome. The last corner on the track is a hairpin connecting two very long straights. It was so tight I was dropping to first gear leading onto the rear straight. First gear in my car doesn't really work, as the car simply overpowers my 280/650/18 Yokohama slicks due to the light weight of the car. But, it felt faster than lugging second, so I continued to drop down and attempt to drive through the wheelspin for the duration.

The main event was looking awesome. I run in GT2, due to the tub-based nature of my car, the displacement (it's only 1.3l ;-) ) and the kindness of my local sanctioning body. In the qualifying order, I was a few cars ahead of the nearest GT2 entry, making a class win look possible. We pulled out on track, ran the warm-up laps and got underway. My car felt very fast. I was pushing it hard and it was hooking up awesome. The temperatures were low 180-190 degrees for water and 200 for the oil, even with the extra boost. The Aquamist had dropped a good 10 degrees from my normal water temps and over 30 from my normal oil temps, even while I added another 60 or so hp. Everything was going great until we started to see smoke from the car. As the race went one I continued to lead the class, but the smoking was getting worse. On hard acceleration, the smoke was pretty think, as the car gained speed it seemed to smoke less. We continued to run hard and then, with about 10 minutes left in the race, the transmission let go in third gear. I run a G-force T5 dog box, so I knew it wasn't going to be cheap to repair (turns out the plug in the back of the shifter popped out due to a blockage in the vent line and caused the tranmission to shoot most of the gear lube onto the exhaust) . But, I pulled the car in and we pushed it back to the pits. End of season. Overall finish was in the high 20's, but the car was working well.

Thanks for reading this far. I got a lot more long-winded than I expected, but I wanted to provide a context for my opinion on the HFS-3.

Summary: AI is awesome. You can run more power with less heat. The Aquamist setup with the anti-slosh tank from Howerton didn't miss a beat between 1.6 G corners and 155 mph to 40 mph braking zones for the duration the transmission held together. You should do AI. I like the Aquamist a great deal and would encourage anyone to short list it when doing your research.

-TrentO