ok so i think i can explain the dip in the power on the 399hp run, originally i thought the fuel was dipping rich because of that, but closer inspection shows the fuel went rich before the dip in the RPM's and the fact it went to 3.9 AFR (0.60 lambda) which i reckon caused the flutter i heard at that point, probably because it was almost flooded, and then before i could back out of the throttle it came back on song and i kept into it till shift light.
i also reckon having that much fuel in there probably half burnt meant it was burning in the exhaust and spooling the turbo up even more, hence the boost spike ....
so on the boost controller side of things, i have the answer there...... what happened was it was boosting to 22psi on initial throttle application (before the ramp run) so i thought maybe the flex table at 0% needed to be inverted, so i put 100% in the entire thing, this didn't make a difference, so i ended up just removing the boost controller ......
turns out i had mixed up the boost controller and second fuel pump flex tables, so when i hit 105kpa and revs got over 4000rpm the second fuel pump was supposed to come on, but instead it made the boost controller go 100% duty cycle which explains what i was seeing!
on the up side, me filling the table with 100% also meant that the second fuel pump was on all the time, so i didn't tune it on one pump, but more importantly i think over about 330-340hp is when i need the second pump so i didn't torch the motor!
so i am a bit annoyed that i wasted time on the dyno with all this and wasn't able to dial the boost table in a bit, i am also happy that everything makes sense and i know where its at!
im not sure when but i have a score to settle on the dyno so i will return and send it on 20-25psi maybe later on in the year - as for 399 ... i know there's more on the table and i will push this combo to 30psi if i need to
im also happy to go to Gunnedah now and can work on slowly ramping up the boost table.
