VG30dett rpm issue

[kevin p]

I'm getting rpm cut at high rpm before it reaches the limiter, also when the boost is turn up it misfire. 

Is there a limiter or something that I'm not seeing?

File and log attach.

 

Thanks 

johnz - 2022-04-29 3;41;45 pm.llgx TriggerScopeLogjohn.llgx johntestboost.pclx

[Brad Burnett]

Id start with spark plugs.  Whats the gap set at?

[Adamw]

The RPM limit is functioning correctly in your log.  The commanded limit was about 7500 due to the coolant temp being at 95°C.  With your control range at 100RPM the limiter will start kicking in at 7400RPM.  Although the log appears to show it coming in about 7150 & 7300 the 2nd time, this is just because there is filtering applied to the RPM value recorded in the log and the slowish PC logging rate will miss small spikes of RPM.  If you log RPM at say 500Hz you will likely see more detail that reflects your expectation. 

As for the high boost misfire I would agree with Brad, this is usually a lack of ignition energy, as cylinder pressure increases you need higher voltage to jump the gap - or make the gap smaller.  

 

    

[kevin p]

The car has R35 coils and the gap is at 18 with NZ trigger.

I've been trying to solve that issue for a while. On the dyno chart after 5500 rpm the curve is very wavy. Is seems like if the coils are not holding up or the dwell is not right. However I have tried different setting on the dwell side if thing with no success.

I will go back to the stock trigger set tomorrow and see if that fixes the problem.

[kevin p]

I reinstall the stock CAS and gap the plugs to 16 and yet again the same problem. I attach a dyno graph for viewing as well. Thanks for all help.