I have spent past two weekends tuning the evo on meth and its been a lot of fun, got the car trapping 115.42. I have one major problem though, no matter what I do as far as tuning goes I have knock at 5k 6k and 7200. Sometimes it one of them sometimes it knocks at all three. I have tried everything I could think of but it just won't go away. Its between a 3 and 5 count typically and the 6k is usually when I flat foot shift.

 

I think your hitting a resonance point on the engine.. I've seen it at 5500rpm on many different cars.. Not at 6k or 7.2k though.. Sometimes you might transfer vibration/shock to the crank when you flat-shift which can result in a knock count too..

 

So how do I go about adjusting the knock setting so I can avoid it pulling so much timing? I have it pull timing pretty aggressively because of the meth.

 

Well, honestly I can't say for sure, on my car I don't get any of this except for some minor (1-3 counts) of resonance knock.. You might have to pull some timing in the cells prior to the knock appearing, and add a bit of fuel.. Its possible due to the engine speed, the knock your registering is in a different location than your adjusting currently (a few lines in the log before the knock event) etc..

You can increase the knock thresholds and how much timing it pulls per revolution.. That might help a little, but if your getting good results with the knock settings, I would try to avoid that.

 

Thanks for the advice, I will try to tune it some more at the track and see how that goes...

 

just a note....

we found our balance shaft belt/pulleys was off one tooth from the factory, when we did our first head work..... was creating a vibration and knock around 52-5800 rpm... once corrected, we did not see the problem.

cb

 

I never thought of something like that, I will check that next time I have it up on the lift, thanks...

 

Thats actually really common, the timing marks on the damn front of the engine aren't the easiest to see or line up... Its too easy to be slightly off if your not paying attention. However I checked mine and it was dead on and I still get that resonance occasionally.