RB25 Breaking up under WOT and high RPM

[bagirard]

I'm from BC so I've posted on BC240 already but I figured someone here could probably help me better. Here's the link to my thread. Any help is greatly appreciated:

http://bc240.com/index.php?showtopic=6847

[Darius]

This is exactly the sound mine is making at high rpm and full boost. I can't figure out what is causing it. I have LS2 coils so it probably isn't the coils.

My tuner noticed the CAS signal was somewhat "noisy" while I was on the dyno earlier this summer, so I'm wondering if that has anythingn to do with it?

[bagirard]

Wow that sucks lol I was about to order up some ls2 coils hoping they would fix the problem.

[Yellow4g63]

That sounds like detonation tho? or maybe the vct rattle that some S14 SR20DET.

[Shocker]

Check to make sure you have proper grounds to the engine block and chassis. Also gap them down to 0.022 see if that helps. Stock ecu? And coils? Type of plug?

[bagirard]

Stock ecu, stock coils, NGK BCPR7ES plugs gapped at 0.028". I've never seen anyone gapping tighter than that?

[Darius]

That sounds like detonation tho? or maybe the vct rattle that some S14 SR20DET.

I'm not getting any knock indication except maybe some noise when the exhaust note changes from normal to irregular sounding.

[bagirard]

My exhaust note never changes. You can hear a bit of sputtering when it misfires but the tinging sound definitely sounds like its coming from the upper passenger side of the engine bay. Around the head area.

[Darius]

hmm do you have any way of monitoring knock? Like Power FC? Mine is definitely a change in exhaust note and sounds like crackling.

[Shocker]

Stock ecu, stock coils, NGK BCPR7ES plugs gapped at 0.028". I've never seen anyone gapping tighter than that?

Well that's funny because we run the same plug and mine are gapped at .022" without any breakup issues. I also run lq9 truck coils however. Gap them down and see what happens. If it continues id start to suspect the ignitor.

As I said earlier do verify your grounds its easy to over look that stuff on a fresh rebuild. I did on my last one and had ignition issues....

[bagirard]

Mine's a series 2 so they're built in ignitors. I'll try gapping them. As fir tge grounds, I'll double check but I know I didn't miss any. I was Very thorough in my rebuild and I didn't end up with any "extra" nuts and bolts or anything once it was back together. But I'll double check the locations for good contact. Which ground specifically should I look at that would affect tge coils the most?