So today I went down to the shop and installed my new Siemens Deka 83lb/hr injectors, made a few calibration changes, fired it up...and was rewarded with a car that now streets like a factory street car.
Injector pulsewidth is well off the minimum pulsewidth floor now; above 2ms most of the time. Fuel control at idle is great; it idles at 14.7 on the money. Cruise is also great; it cruises at exactly the values I command in the tables.
Moral of the story...160's are just not fast enough to meter the proper amount of fuel at idle; the 83's work better than the 160's ever did...even when I had the fuel pressure cranked all the way down to 15psi.
As far as power, they were also easier to tune. I had the AFR flat at 11.7:1 at WOT on the 2nd pull, which netted 662 SAE horsepower to the rear wheels at 5500RPM before the engine misfired badly and stopped pulling. I have the gap set to .032 and was a bit surprised I was having ignition issues, until I logged the run and played back the data...14.5PSI at 5500RPM; the boost at the top end is taking off like a rocket; not linear...it's gaining more PSI per RPM above 4000RPM than it did below...it looks almost exponential. Man, that's a lot more boost than I expected. At it's current rate, I'm guessing I'll probably see 18PSI by the time I reach peak power...which surprises me considering the head flow (ported blue thunder B's).
Total advance at 5500 is still 16deg.
Power is 662 to the tires at 5500rpm when it hits the wall due to ignition.
Torque out of the hole is 500ft-lbs, ramping to 650ft-lbs by 5500RPM, where it peaks. The torque is almost flat when you look at it; than you 385! Surprising, considering it's a centrifugal.
Mind you...91 octane pump gas, no advance, and 11.7:1 AFR.
Peak power will be somewhere above 6500rpm and I'll explore that after I regap the plugs. 700 is certainly in the bag. 750 should be very doable. My goal of 1000fwhp may be slightly out of reach on pump gas. In fact, I'm not all that thrilled about seeing 18psi on pump gas without an intercooler; that's usually not such a great idea due to intake temps.
Since I had plenty of other work to do, and this is more than enough power to get to know the car, and I didn't feel like pulling hot plugs, I left it alone for now and diverted my energy to other things that needed attention like brake balance, clutch (hard to engage reverse because clutch doesn't fully disengage), and my installing my new steering wheel, as well as some seat time to dial in the driveability.
I finished all that stuff today, then left my truck at the shop and drove the Cobra home. Man, it sure is nice now that it streets. I was tooling along in traffic at 1600rpm in 6th...smooth, no bucking, no fussyness, just plodding along with a big smile on my face, bugs and all.
Then, near my exit, some guy in a GT500 ran up me and wanted to play. Suddenly my exit didn't seem so important anymore.
We slowed it down to about 40mph, I left it in 3rd, and rolled off on the freeway. I think this is probably the first time when he looked over and saw the other car still next to him, because the look on his face was priceless. I then dipped into the throttle in 4th for a few seconds and all I saw in my mirror was teeth from his grin. I think he was happy with that loss.
I slowed it down, he cruised on by slowly and did the whole "I'm not worthy" bow while laughing his head off and mouthing "WOW". I grinned and give him a thumbs up and a mouthed "nice car".
That was the end of a great day...now it's time for a shower and a nap!