False knock after some changes, ideas?

[andrewtac]

KR only goes to about -1.5. It used to go to -4. I installed nitrous, single shark nozzle into the snow meth ring. Results are the same nitrous on and off, and immediately at throttle slam. I didn't disturb much on the front of the motor. I did pull the tube from the throttle body, along with where the maf sensor is, but I have done this numerous times. I added the nitrous lines, but everything is zip tied back or bolted down.

Where do I start? What would cause it?

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[Cory S]

It’s still adding timing. Just not quite as much.

 

[silverbullet85]

Negative knock means it's adding timing

 

[andrewtac]

It’s still adding timing. Just not quite as much.

Correct, but same tune, no only adds 1-2, where is used ro add 4. No changes to the tune.

 

[Jackson1320]

Not false knock. Maybe bad fuel. False knock would take all the advanced timing away and go positive

 

[andrewtac]

E85, measured it I think it was around 87%

 

[illtal]

E85, measured it I think it was around 87%

Where are the nitrous solenoids? If it is close to the knockers it maybe can hear them click but not completely.

Or you got a dry system and that's all it can add with the nitrous onset, or the throttle plate, try it without it. See if your timing comes back if you can.

If you're spraying nitrous I think the lost timing is a mute point.

 

[andrewtac]

Where are the nitrous solenoids? If it is close to the knockers it maybe can hear them click but not completely.

Or you got a dry system and that's all it can add with the nitrous onset, or the throttle plate, try it without it. See if your timing comes back if you can.

If you're spraying nitrous I think the lost timing is a mute point.

I did two pulls to compare. One system not armed (no power so solenoids not firing), and the other with it armed buf the bottle not hooked up (solenoids fired); same results. I found a couple plastic items that could have been hitting the pipes and have fixed them, but haven't made another pull.

I am currently not spraying enough to need to pull timing (at least not several degrees), maybe I should turn it up to match. It is intended to reduce the high IATs I saw last summer, and when the built motor comes I'll turn it up.

 

[illtal]

I did two pulls to compare. One system not armed (no power so solenoids not firing), and the other with it armed buf the bottle not hooked up (solenoids fired); same results. I found a couple plastic items that could have been hitting the pipes and have fixed them, but haven't made another pull.

I am currently not spraying enough to need to pull timing (at least not several degrees), maybe I should turn it up to match. It is intended to reduce the high IATs I saw last summer, and when the built motor comes I'll turn it up.

How much nitrous? Should be enough to negate the lost timing. When are you going to get back on the dyno?

 

[andrewtac]

How much nitrous? Should be enough to negate the lost timing. When are you going to get back on the dyno?

Hopefully dyno soon, getting a larger intercooler and plan on a before after. A little more than a 50 shot at this point.

 

[Basspro302]

Pull it all off and retest?

 

[andrewtac]

Pull it all off and retest?

Want to avoid that if possible

 

[Basspro302]

Want to avoid that if possible

Only way to know, could be chasing a ghost. Have logs comparing pulls?

 

[andrewtac]

Only way to know, could be chasing a ghost. Have logs comparing pulls?

I realize I might have to do this, but wanted to see if it was something else. I need to make some more logs as I found a couple things hitting the pipping; both were plastic but maybe. A

 

[Basspro302]

Whats the total timing at? Probably check the plug gap again. Could be worse tho my old procharged 13 would pull 9* on a hard shift. Never was able to remedy it, just moved on to a whipple.

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