Knocking at 4-4.5k no matter what even with meth injection

[DJ23GSX]

I've been battling knock issue's at 4k and 4.5k rpm's for a long time. It doesn't seem to matter what I run my afr's at it will almost always knock at those rpm's lately. I don't know for sure if its phantom knock or real knock. If you look at my data log graphs from today the knock lines are almost identical in every log. It peaks around 4-4500 rpms and tapers back down to 0. This seems rather strange to me. From all my data logs over the last few days 11.5 seems the be the afr where it will knock the least but it won't go away completely. I've been as rich as 10.6 and this seems to make the knock even worse. Even keeping it at 11.5 I might get 14 counts of knock one pull then 2 pulls later it will only be 6 counts. It always seems to be up and down like that for no obvious reason. I've already tried a different 2g maf with no change in knock. I pulled out the knock the knock sensor and its still in great shape (only about 5k miles on it). I did teflon tape the threads and put a nylon washer between the block and sensor and it might have gotten only slightly better at the very most. I'm not sure when else to look into.

These logs from today are on an Evo3 16g at 25psi, A 600cc nozzle spraying a 50/50 water/meth mix starting to spray around 8psi with full spray around 17psi. I have an old school Buschur racing street fmic, 3" catless turboback exhaust, 680cc injectors, safc, keydiver chip, 2g maf DKS 272's 2g fpr and rail with a Walbro 255 BR7's gapped to .024. I think thats the jist of mods that might pertain to this issue.

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[asexton6969]

To be honest I would probably be running one step colder plugs, BPR8ES. Start with the easy, cheap stuff. Boost leak test and swap out for a colder set of plugs.

 

[Seamus]

Does it knock at part throttle and if you hold the rpm's around there? If so, you can almost definatly check it off as something vibrating or hitting a perfect frequency or something.

 

[DJ23GSX]

No it only knocks at full throttle right after I hit full boost and the car really starts pulling. Everything's calm and quit at part throttle. latest boost leak test only showed very minor leaks the tb shaft seals. I do have a set of bpr8's I can try.

 

[asexton6969]

Sounds good, report back with any changes.

 

[DJ23GSX]

I've got a little more info. I can seem to make a few clean pulls with little to no knock when I first start the tuning pulls then after that the knock seems to start. It's not heatsoak because I've pulled over a few times and the cold side of the fmic is still cool the touch. I'm at a loss here guys what else should I be looking at?

 

[DJ23GSX]

Another tid bit of info I've noticed is that some days it pulls so hard it feels like the front tires are gonna come off the ground and other days its just kinda blah. I constantly datalog the car and nothing looks out of the ordinary except for this knock problem.

 

[donniekak]

You need a better tuning solution. Pulling a couple degrees of timing in that area would fix the knock.

 

[DJ23GSX]

Possibly but even still I don't think my timing is that aggressive considering I'm running meth injection. The fact that one day the car pulls like mad and the next day it's just kinda blah leads me to believe something else is wrong.

 

[donniekak]

Try turning the boost down.