A lil knock with Razors dual nozzle; False ?

[V8killR4U]

Tracking down a small knock issue. Doesnt knock at 12-13 lbs, but i am getting slight knock at 16-17 lbs, I see 1.9 and then 0. on a WOT pass. I have Razors dual nozzle set up Pump speed on the controller is at 4. anything higher and the car bogs bad.

My question is. Is my pump speed too low with dual nozzles for 17lbs of boost at 18 degree timing. Obviously im running duals because i plan on running at least 25lbs of boost and more timing 26 degrees, but need to figure out my knock issue before i turn it up. It shows 1.9 knock at about 4500 rpm, every single time then goes to 0 knock immediately. Am i chasing the infamous false knock.

I was thinking of using one nozzle and turning up the pump speed to see if that does anything. Should I do that? or just keep it on?

Suggestions

 

[V8killR4U]

Nobody has any suggestions?

 

[Sweet6]

When is the knock ocrruring? 1st gear, 2nd gear? You could get some knock as soon as you crack the throttle. I have had knock before when I first crack the gas. What are you using for a Scan Tool?

I would guess it is false knock if it goes away quickly. If it was lean, it would keep knocking.

 

[V8killR4U]

Looking at my runs recorded on the PowerLogger Knock is occuring in the 4K plus range in 3rd gear. So im assuming it isnt false now.O'2s look good 820-830 range with the dual nozzle set up with on pump speed set at 4

 

[Roc87]

Thats a pretty low boost to be getting knock. If it were me, I'd find some race gas, turn off the alky kit for now and make a couple runs to see if it still shows knock, if it does, then you know for sure that it's false.

If it doesn't knock, enjoy the rest of the tank of race fuel, then fill up with pump gas and get the alky kit turned back on. I'd probably try one nozzle and higher pump speed setting since you are saying it's bogging down with the dual.

Some guys can run 125+mph in the quarter with one nozzle, I wasn't one of them. I have the controller at 6 with an M10 & an M15 nozzle running 27-28psi with almost 25 degrees timing, ZERO knock even when it's in the 90's. What size nozzles are you running? The times in my sig were with dual M10 nozzles and controller maxed out, I still got 2 degrees knock in third, but still running 27psi.

 

[Razor]

Its always easier to dial in a single nozzle system as the volume being dealt with is less. At 16-17 PSI boost you really dont need a lot of alky and turning the knob(1-8) down on the system to reduce alky volume can make the system lazy coming up on pressure.

Typically with Gain settings over 5 on a Buick without messing with the internal controls, the pump should spin up fine. If you start going lower than that, then the pump can initially stall when you go into boost and create a delay in getting alky into the engine.

In laymans terms, the alky pump is a 12 volt motor. When you activate the alky system(6 psi boost) you want enough voltage signal being sent to the pump to effectively spin its motor. The pump needs to see 3.5 volts to get it to spin predictably. If your the "Gain" down and only send 2.5 volts to the pump.. it may not spin predictably. Kind of like trying to start a car when the battery is down to 10 volts(may or may not crank). The way this can be seen is connecting a digital voltmeter across the red/black pump wires and hitting test. This is why with Initial as preset.. the gain should be probably be in my opinion higher than 5. 4 may or may not yield enough voltage to always spin the pump. Some cars it will.. some wont.

So since you have both nozzles installed, turn the gain knob up to 5-6.. and tune out the alky by reducing fuel coming into the motor.. or go to a hydrualic or plumbing store and get a -4(1/4 female) caps and cap off one of the lines going to the nozzle and turn up the gain.

Cars that have the aftermarket computers like FAST just turn the alky up.. dial out the fuel. no problem.

HTH

 

[V8killR4U]

Its always easier to dial in a single nozzle system as the volume being dealt with is less. At 16-17 PSI boost you really dont need a lot of alky and turning the knob(1-8) down on the system to reduce alky volume can make the system lazy coming up on pressure.

Typically with Gain settings over 5 on a Buick without messing with the internal controls, the pump should spin up fine. If you start going lower than that, then the pump can initially stall when you go into boost and create a delay in getting alky into the engine.

In laymans terms, the alky pump is a 12 volt motor. When you activate the alky system(6 psi boost) you want enough voltage signal being sent to the pump to effectively spin its motor. The pump needs to see 3.5 volts to get it to spin predictably. If your the "Gain" down and only send 2.5 volts to the pump.. it may not spin predictably. Kind of like trying to start a car when the battery is down to 10 volts(may or may not crank). The way this can be seen is connecting a digital voltmeter across the red/black pump wires and hitting test. This is why with Initial as preset.. the gain should be probably be in my opinion higher than 5. 4 may or may not yield enough voltage to always spin the pump. Some cars it will.. some wont.

So since you have both nozzles installed, turn the gain knob up to 5-6.. and tune out the alky by reducing fuel coming into the motor.. or go to a hydrualic or plumbing store and get a -4(1/4 female) caps and cap off one of the lines going to the nozzle and turn up the gain.

Cars that have the aftermarket computers like FAST just turn the alky up.. dial out the fuel. no problem.

HTH

Check out my new post.

I've gone from a low pump speed 3-4 and 15-16 lbs of boost too 20lbs of boost and pump speed on 8 and o2's are in the 815 range. Im throwing alot of fuel at it and only running 20lbs of boost? It seems like Ive gone from one extreme to the other? I dont have a double pumper however, could this be the reason. This is originally why I went with the dual nozzle.

http://www.turbobuick.com/forums/alcohol-nitrous-propane-tech/260023-whats-next-alchy-setting.html

 

[86BLACKT]

How much fuel pressure are you running and do you lose it at top?

 

[V8killR4U]

How much fuel pressure are you running and do you lose it at top?

42 lbs line off, my eyes were on the scan master. ill look at the fp on my next run to see if it drops off.

I started a new thread too.