More false knock

[TooSoonJunior]

Yea I would just get back in touch with Lund and get him to update the tune, tell him what you observed

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[venumous]

Just saying the fuel system must be bad. I'm going to go another route

 

[dubster99]

It's never a lund tune that is the problem. Ever.

 

[higdominator]

Just saying the fuel system must be bad. I'm going to go another route

You should be able to see a bad fuel system in the logs if it was to the point of causing knock. Even then, it might not even knock. I lost a pump on E85 and at 7000 RPM it was damn near 1.0 AFR and still -3.95 on KR.

 

[diablomatt]

is there any chance that the fuel system itself was hitting something? like a line for a fitting banging against a shock tower or something like that? only thing i can think of. especially with e85. its almost impossible to knock on e85.

 

[smokinzx14r]

is there any chance that the fuel system itself was hitting something? like a line for a fitting banging against a shock tower or something like that? only thing i can think of. especially with e85. its almost impossible to knock on e85.

Not likely ... My fuel lines hit everything , my charge tube hits the core support , the intake tube hit in two spots and I have never seen knock on 93 or E85 ..

 

[diablomatt]

Not likely ... My fuel lines hit everything , my charge tube hits the core support , the intake tube hit in two spots and I have never seen knock on 93 or E85 ..

which is basically what i have seen as well. i have a p1HO car on e85 with a stock converter running 10.0 and have NEVER seen it knock

 

[JennyStang]

It's never a lund tune that is the problem. Ever.

Hahahahah

 

[205.0]

It's never a lund tune that is the problem. Ever.

Yeah lund has never been anything but great working with me and helping me to troubleshoot. Really great people working there.

 

[Jeff_oddo]

I was able to duplicate the false knock this weekend. When I would be lightly pressing the gas it would show a very slight knock retard each time the car would shift. I think I can now narrow it down to having the poly engine mounts and BMR poly differential lockouts. The added NVH is causing it. I also switched back to my stock tune and then reflashed my Lund tune as well last night. So far no knock retard when driving into work.

 

[ProChargerTECH]

I was able to duplicate the false knock this weekend. When I would be lightly pressing the gas it would show a very slight knock retard each time the car would shift.

I tuned a car that would do that, because of the poor fuel in his area.
It would ONLY do it on the shift.


It wasn't actually false knock...

What I did was an adjustment on the timing tables and reduction in the areas of where it shifted. Just a few degrees in change eliminated it completely.

Then once it was gone, the car would actually add more then ever in all the other areas of the power curve. So always positive timing being added all the time (2-3 degrees)

 

[Jeff_oddo]

I tuned a car that would do that, because of the poor fuel in his area.
It would ONLY do it on the shift.


It wasn't actually false knock...

What I did was an adjustment on the timing tables and reduction in the areas of where it shifted. Just a few degrees in change eliminated it completely.

Then once it was gone, the car would actually add more then ever in all the other areas of the power curve. So always positive timing being added all the time (2-3 degrees)

I'm on E85....

 

[ProChargerTECH]

I'm on E85....

It can still happen. (just fixed a car about 3 weeks ago for that, was on E85)
This one recently was on pump 91 though.

But basically when the trans shifts and the cams move.
There is a moment where very rapidly it can swing to some different timing tables. If there is to much spark in those tables, it knocks, then jumps back to the OP tables

 

[Jeff_oddo]

It can still happen. (just fixed a car about 3 weeks ago for that, was on E85)
This one recently was on pump 91 though.

But basically when the trans shifts and the cams move.
There is a moment where very rapidly it can swing to some different timing tables. If there is to much spark in those tables, it knocks, then jumps back to the OP tables

Interesting

 

[ProChargerTECH]

Interesting

Log the TQ Source, and see if there is a jump right before or after the knock happens.

I just saw a car jump from 16 degrees to 33 degrees, and back within a fraction of a second. My friend had the car up in MN, and sent a log over to me to take a peek at and that was the first thing I saw.... had him contact his tuner to resolve that area. Once it was resolved, car never ever knocks now.

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