Idle Ignition Timing - S1 RB25DET

[Freebaggin]

I have programable ECU and wanted peoples opinion on the best idle ignition timing to use, it's currently 14°.

I have idle probs sometimes but I have big injectors, light flywheel, big turbo and exh cam timing retarded that don't help. I have also played with fuel (dropped) to improve city cycle fuel econ. so I can easily increase it up again to get rid of problem but I want to be more smart about it.

Apart from trying it, will an increase in timing from 14° improve idle quality and reduce stalling etc?

[blind_elk]

I'm running a Wolf 3D on a Stagea RB25DET, standard injectorsa, but light flywheel. At idle (around 800), its got about 16 deg, but at the rev point below idle its got 19. Apparently produces more torque to pull the engine out of a stall.

[666DAN]

I would honestly have thought the bad idle was a function of the idle duty cycle...as when warm I'm sitting on 5 degrees advance with no issues.

[666DAN]

Actually ignore that comment, I've got v-high compression as well.

[Evil]

I thought the timing for an RB25DET was 15 deg. I'm pretty sure thats what the Nissan sticker says under my bonnet. i have a very smooth idle... it has been set to 740rpm... according to my rsm it is never more then +-10rpm!!!

[Chris32]

I have programable ECU and wanted peoples opinion on the best idle ignition timing to use, it's currently 14°.  

I have idle probs sometimes but I have big injectors, light flywheel, big turbo and exh cam timing retarded that don't help.  I have also played with fuel (dropped) to improve city cycle fuel econ. so I can easily increase it up again to get rid of problem but I want to be more smart about it.

Apart from trying it, will an increase in timing from 14° improve idle quality and reduce stalling etc?

I reckon you are on the right track, as I have backed by base timing of a little and it caused a slightly lower and rougher idle

I adjusted this using the idle control valve on the plenum, but I reckon a small increase in timing (say around 1 to 2 degrees) should make it better rather than worse

[blind_elk]

I adjusted this using the idle control valve on the plenum

Nothing to do with ignition timing. All it does is change the amount of air bleeding into the plenum at idle (closed throttle).

[Freebaggin]

Thanks guys.

Actuall I should clarify, idle quality is OK, it just stalls under certain conditions with the current fueling I have.

I had a go on the way home from work....plenty of bloody idling opportunities!... and increased from 14° prgressively to 16°. Was funny though, woudl still stall sometimes but other time with all parameters the same it would be OK. The ECU has other idle functionality I need to play with so I'll keep ya posted.

Edit: Just read in book that 15-32° is typical for motors, so I'll jack it right up and see how it goes.