Can't get rid of knock in 3rd

[DougsfastZ]

Here is the run down, stock turbo, motor, and intercooler. Homemade alky kit using a shurflo pump wired to a devilsown controller, using an M15 nozzle. Fuel pressure is 45 psi static. Turn on is 12 psi, full alky is set to 17. I run 21 psi first and second with no knock and the 02's in the high 700's. As soon as I shift to 3rd (boost creeps to 22), 02's begin to fall and knock starts to creep in. I've seen as high as 5 degrees and 720 02's by 4800 rpm in 3rd. I don't think I should add any fuel pressure since it is already at 45. Is the M15 nozzle bigger then the M10? What is the factory shurflo pump psi setting? Should I turn up the pressure on the pump via the screw on top? Any ideas on how to get those 02's up and that knock down in 3rd? I'm also no locking the converter.

Thanks,

Doug D

 

[suicide six]

Is your fuel pressure at 67lbs at WOT while at 22lbs boost?Pump may be at its peak,fuel filter needs replaced.What chip are you using and can it be tuned at WOT? With 720s at WOT w/alky maybe the alky is effecting that reading.O2s are hard to use w/alky.A egt system would be a better or actual reading. 45 static may be high for your setup and alky throwing O2 reading off,it may be a rich knock.

 

[suicide six]

http://www.turbobuick.com/forums/showthread.php?t=147348&highlight=alky+tune

 

[suicide six]

Faulty ignition wires will give you a false knock too.Is your chip setup for alky?

 

[DougsfastZ]

I always forget some details Its an extender chip with a translator +, not sure what the boost is set at in the chip. I'm using an RJC boost controller bypassing the stock boost solinoid. I'll have to check fuel presuure at WOT. The fuel filter is new and the pump is a Walbro 340 hotwired. I'll have to get an EGT gauge.

Thanks for the help.

Doug D

 

[WSLN 6]

You shouldn't be getting boost creep, that isn't helping matters any. Open up your wastegate hole a bit. Make sure fuel pressure is following boost.

 

[DougsfastZ]

Fuel pressure is following boost. I was able to stablize boost at 23 in all gears and got rid of all my knock. I turned the allen screw on the pump 1.5 turns which believe turned up the pump pressure since my knock went away. The car ended up going 12.44 @ 106 no converter lock up.

Doug D

 

[TTA]

You might have too much timing. I wouldn't go higher than 23/21.