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knock and scanmaster

2K views 7 replies 6 participants last post by  Razor 
#1 ·
ok so i am pretty clear on how knock is measured on these cars and how to determine if it is real or false knock and i have come to this conclusion, i can only run about 16psi w/o knock and i am getting some false knock on shifts. what i didnt realize is when i ordered my turbo i got the hd actuator and it only goes as low as 19 psi even with my manual boost controller turned down and the rod adjusted out. i think it is knocking b/c my fuel pump cant keep up, i have a walbro 340 and im gonna put it in soon but should 19psi be ok to run without alky w/o getting knock?? also i hit recall on the scanmaster last night and it read 770something and 0.0kr what does it mean when it records 0? wouldnt it just stay blank the screen like every other time it doesnt knock?
 
#2 ·
You're doing well to hit 18 PSI with zero knock...and you shouldn't be tempting fate going WOT with a suspect fuel pump.
 
#3 ·
Normally, I would say 17 was about the top altho a few manage to get more...

If you don't have a good fuel pump and hot wire, then you will soon be spending a few thousand on a new engine.
 
#4 ·
I did 2 runs with the HD Actuator tuner style & rod with just 1/8" tension. I saw 16-17 lbs both times.
 
#5 ·
well i guess im gonna have o play with the boost controller a bit more and see if i can get it a bit lower but no more rippin it till i put this fuel pump and wiring in.. at least my new ignition module cured my stalling spoblems and more exhaust dump just came in so i cant wait to hear that. thanks for the help guys
 
#7 ·
i guess that makes sense since the actuator is setting the baseline boots by opening the actuator, but then say i get this fuel pump working and some alchy and i wanna turn up the boost, would i have to adjust the rod and the boost controller? i am thinking for the first time i will i have put more tension on the rod and after that i can go up or down with the rjc manual controller?
 
#8 ·
Typically boost controllers bleed off boost, or restrict how much boost hits the WG diaphram. This is how boost is raised.

HD actuators typically start at 18 PSI boost, not lower. And if you have a street chip, the fuel it commands is to support 16 PSI not 19 PSI. So as the boost is higher than 16, you need to add fuel through the injector pulse width.

You can have a Godzilla fuel pump/system and if the chip is burnt for 16 PSI.. your going to be lean at 19 PSI.

Scanmaster only records when throttle goes past half way. Since you cant mash the pedal, you get a blank screen.
 
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