honda9krpm

I've been checking my knock logs. I am aware that vtec transition is often a noisy thing. Just out of curiosity, how much back ground noise (= knock volts) do you get with your turbo setup just right after vtec engagement?

Tinker219

During tuning, I did see a 3.75 volt jolt right at 6krpm, but was able to bring it down to around 2.5 volts(with 2 or under everwhere else) with tuning.
If you cant get it down, its probably the valvetrain making unavoidable noise. If youre seeing much above 3 volts, and you cant get it out with tuning, then pay attention to whether timing is being pulled when Vtec engages. If it IS, then you probably have a problem somewheres...

honda9krpm

I am seeing around 3.8V when the high cam lock in (vtec engagement) with avgas. It's quite interesting to see such loud event. From what I gathered from the aem forum this is fairly normal.

I will try pull a few degrees when vtec engage and see whether this makes any difference. I will also check my tappets.

BTW what did you do to lower the voltage around vtec transition?

Tinker219

I didnt mess with the timing at all, although I would IF I were comfortable with doing so.
I simply messed with AFR; Im actually fairly consistent at 11.5-11.8 AFR. The new manifold/DP setup likes the higher AFR a LOT better than the other setup so that means I could see a LOT more power with timing adjustments; just have to get the courage up to start messing with it. With 15000 TURBOCHARGED, heavily beaten miles, something must be right in the timing