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RB26 detonation / timing questions

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I have some questions on typical timing to start when working through a VE table. I am working on the tune for my rb26 with a link ecu. The engine is fresh and I'm running a 6262 precision and poncams with supporting modifications. Also i've converted to an AEM CAS disk and run some rpm filtering. Currently just on wastegate pressure at 15psig. and 93 octane fuel (in the US) The issue that has cropped up is that as I work through high and WOT runs in the VE table I see detonation through the knock control mostly near where the onset of torque is (4k - 5.5k rpm). I keep pulling timing and have nearly cleared it up but but my timing in these areas is now near 5deg BTDC. Is this normal? other similar engines I have tuned are more near 10-12 deg. safely. I have checked and rechecked the base timing settings and I feel like I'm missing something? I was anticipating ending up with 20-25 psig on this engine and am not sure I'll make it there without timing ATDC. Thoughts?

Oh yes and to compare the base map for this engine has timing in the 12 deg range in this area of the map

That doesn't sound right for 15 psi boost. The RB26 normally accepts timing reasonably well. My first thought would be that the knock control strategy in your ECU is not properly calibrated and it's reporting false knock. Have you confirmed this with audio knock detection? I'd expect you to be in the low to mid teens around peak torque and probably in the low 20's by the rev limit at 15 psi.

Thanks, I dont have an audio system yet so I'm relying on the sensor outputs. I'm also getting some trigger errors and rpm signal fluctuations when this happens. I attached a screenshot of a log.At this point I'm trying to decide if I should invest in a knock audio system or a crank trigger kit. I'll go back through the knock settings though. Also I'll note that timing changes are helping but not curing the problem.

Attached Files

If you've got trigger errors like your log shows then your ignition timing is likely bouncing all over the place.

The aftermarket CAS disc's are rarely much of an improvement since you are still left with an optical reader device that is 30 years old, the lenses are usually cracked and/or opaque and another other horrible design choice with the nissan CAS is it couples sensor ground to chassis ground through its body so its signal is quite noisy due to this.

A lower cost & easier alternative to a full crank trigger kit that works very well on the RB's is this: https://www.nzwiring.com/index.php/product/trigger-kit/

Even though it doesnt get rid of the fact that it is still connected to the crank via a flexible belt, the difference in trigger quality compared to the nissan CAS is night and day.

Thanks, I'm definitely going with that kit. Andre actually recommended it to me previously and I didn't understand why it was better than a low resolution CAS but it makes good sense now.

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