The race truck is finished (knock on wood) and I have an all-day dyno session booked for this Wednesday (March 5, 2010). I have installed a smallish dry NOS set-up (one NOS fan nozzle + .021 flare jet in the intake piping after the intercooler . . . and one NOS fan nozzle + .021 flare jet right after the supercharger). I also put a .061 flare jet for each line at the NOS y-block to reduce the initial NOS surge at the hit of the button.
I will develop four O2-based maps from this session: (1) just the motor up to 7000 rpm; (2) the motor plus the after-the-intercooler NOS nozzle only; (3) the motor plus the at-the-supercharger nozzle only (more time for the NOS to "exchange heat"), and; (4) the motor plus both NOS nozzles. My guesses are (at 6000 rpm): (1) 425-450rwhp, (2) 460-485rwhp, (3) 465-490rwhp, and (4) 530-555rwhp. Wish me luck. I plan to use the NOS only for qualifying for "Top Truck" events with the AEM turning on the NOS at 3700 and off at 5700 . . and shift at 6200.
I have been in pretty steady contact with my shop guys and although the progress has been far from swift, it seems like all issues have been sorted. The starting and idling issues related to the fact that the Subaru injectors DO FIT the 1UZ intake manifold, but they do not fit well. . . . the rubber swelling issue is prevalent no matter what gas you use. So, the fix is to make some small aluminum "washers" top and bottom of the injector so that the rubbers are held firmly in place (the lower washer) and also to make sure the injector does not get jammed too far up into the fuel rail (the upper washer) to compress the rubbers so they have no room to expand (like the standard 1UZ injectors). I discovered this from other 1UZ racers here. What a hassle . . . but necessary. They do not suck air around the injectors now . . . and they will not allow boost to blow out either. With that done the thing starts up immediately, but still wouldn't idle below 2500 rpm . . . what's up? After a long search the throttle shaft of the throttle body was found to be so loosely fitted that it sucked gobs of air in there. I have a better, high quality throttle body (80mm) to fit now. These little details . . . flaws of quality, have cost me a lot of time. So now I am only waiting for next Wednesday.
I got to worrying that my single Bosch fuel pump would not be enough when I added a dry NOS jolt . . . and Jeg's was having a sale on the Aeromotive A1000 FI fuel pump . . . . so I ordered one with fittings. The specs are great:
A1000 (#11101) Specifications
-10AN inlet and outlet
Flows 700 lbs/hour @ 13.5 volts/45 psi
Fuel injected engines:Up to 1300 HP for naturally aspirated up to 1000 HP for forced air induction
As can be seen from the accompanying chart (below), this is a very good fuel pump which should provide me with adequate fuel delivery for any future modifications up to 750+ horse power . . . . and will have the volume when the NOS switch is thrown. I currently use one 040 Bosch.