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Rb30/26 Base Ignition Timing

sky30

By sky30,
in Engines & Forced Induction

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GTRNUR Grand Master

GTRNUR

Posted
Posted

By base I presume you mean idle?

It will depend on your cams, and if you want it to idle nice... and not stall out when the aircon comes on.

I set 20 degrees at a 900 RPM idle, and advance to 22-23 degrees below 900 rpm, and also in the next load cell up. When the aircon goes on, or electrical load increases, the engine produces more torque with the ignition advance and it will auto-stabilise back around 900 again.

RB25's advance the intake cam at idle which improves vacuum and decreases lobe seperation making the idle smoother. You'll find that auto's vs manuals have differing idle advance settings too, to accomodate for the load of being at idle in gear with a torque convertor slipping but on the verge of engaging. Im pretty sure the RB30 manuals are 15 as per the manual, and 20 for the autos. Rb25's with VCT change the rules by making the idle more stable by advancing the intake cam. It is then retarded off idle and advanced again for top end power.

sky30 Mentor

sky30

Posted
  • Author
Posted

By base I presume you mean idle?

It will depend on your cams, and if you want it to idle nice... and not stall out when the aircon comes on.

I set 20 degrees at a 900 RPM idle, and advance to 22-23 degrees below 900 rpm, and also in the next load cell up. When the aircon goes on, or electrical load increases, the engine produces more torque with the ignition advance and it will auto-stabilise back around 900 again.

RB25's advance the intake cam at idle which improves vacuum and decreases lobe seperation making the idle smoother. You'll find that auto's vs manuals have differing idle advance settings too, to accomodate for the load of being at idle in gear with a torque convertor slipping but on the verge of engaging. Im pretty sure the RB30 manuals are 15 as per the manual, and 20 for the autos. Rb25's with VCT change the rules by making the idle more stable by advancing the intake cam. It is then retarded off idle and advanced again for top end power.

Yes base timing at idle is what i was talking, mine seems to like 15 degrees rather than 20, using the rb26 head, with some decent cams.

STATUS Grand Master

STATUS

Posted
Posted

need to plug in consult and lock it then set to whatever the ecu is reading... can never assume. Its common for the factory ecu to swing 5 degrees at idle and if you dont lock it its very easy to get it wrong... base ignition is the root of many engine issues... i reckon it is one of the most common owner induced mistakes we have to rectify for customers....

rob82 Mentor

rob82

Posted
Posted

Running autronic sm4.

Just wondering why some rb motors are 15degrees and some 20?

If you running an SM4 you can run delta ignition control. It also has an rpm rate varaible so that you can apply positive or negative ignition changes based on the direction of rpm change - not just under or overspeed rpm event. Great ECU btw - my favorite. Who's pushing the buttons?

rob82 Mentor

rob82

Posted
Posted

Ah, yes i seen that function, would be great for cars without idle solenoid.

After some fiddling with settings, i got mine running well using the stock solenoid.

Its great for cars with idle control valves also. You will find that most manufactures run both an idle control valve and delta ignition control. Engine speed responds alot faster to a change ignition request than a change in idle air flow....

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