Knock @ WOT - 427 A6 LS3

[fe9_fe9]

Hi All,

Car is not mine, it's a friend's and I'm helping him tuning it. So I don't know the inside and outsides of the car. It's a 2008 A6 Cope with a 427 LS3 + Heads and Cam. Compression is ~11.3 and we were tuning it with 91 Gas.

I get this intermittent WOT knock with Fuel at ~12.7 and stock timing. I kept pulling timing off and it was still doing it no matter how much I try. Same areas though.

I'm posting a couple of thumbnails to show what kind of Knock I'm talking about. Knock sensors configuration is stock. I don't usually like messing with them if I don't have to.

Any help would be very much appreciated.

Thanks,
Faisal

[carlrx7]

Some things you can do:

1) fatten it up, 12.7 might not be the sweet spot, try 12.0 or a PE of 1.22, if that works, slowly lean it back up till she knocks again then bring it back some .25afr for safety.

2) stock timing plus increased compression = knock. take away 4 degrees as a test. 91 octane and 11.3 is on the edge.

3) add a gallon to a quarter tank of gas to boost the octane. if the knock goes away then its real knock, (see 1 and/or2)

4) (decay rate)Knock fast recover rate vs cylair delta vs rpm. from 2000rpms and down make 1.000

5) (base retard) reduce knock retard attach vs rpm. select all cells and mult by 0.5

these are just suggestions, not rules, try some or all. sometimes you can't aviod knock on some cars (like gto's) so #4,#5 are a must.

-Carl

[fe9_fe9]

Some things you can do:

1) fatten it up, 12.7 might not be the sweet spot, try 12.0 or a PE of 1.22, if that works, slowly lean it back up till she knocks again then bring it back some .25afr for safety.

2) stock timing plus increased compression = knock. take away 4 degrees as a test. 91 octane and 11.3 is on the edge.

3) add a gallon to a quarter tank of gas to boost the octane. if the knock goes away then its real knock, (see 1 and/or2)

4) (decay rate)Knock fast recover rate vs cylair delta vs rpm. from 2000rpms and down make 1.000

5) (base retard) reduce knock retard attach vs rpm. select all cells and mult by 0.5

these are just suggestions, not rules, try some or all. sometimes you can't aviod knock on some cars (like gto's) so #4,#5 are a must.

-Carl

Hey Carl,

What's up man? Thank you for the great tips. I was hoping that this might be some sort of false knock, I guess it's not

[SultanHassanMasTuning]

built engines always produce more noise, the suggestions above are good. also a knock box always helps

good luck Fe9

[fe9_fe9]

built engines always produce more noise, the suggestions above are good. also a knock box always helps

good luck Fe9

Hey Sultan Long time no see bro!

I would understand if it has aftermarket valvetrain, but it doesn't.

Do you use knock box?

[SultanHassanMasTuning]

yes i do, with any thing that is not stock, or tuning a new platform

Hey Sultan Long time no see bro!

I would understand if it has aftermarket valvetrain, but it doesn't.

Do you use knock box?

[fe9_fe9]

yes i do, with any thing that is not stock, or tuning a new platform

Will drop by