Timing advance

[partsman93274]

I have my 91 4runner 22re. Has anyone notched out the adjustment lobe on their distributor to get more advance out of it? I'm tempted but not sure if it is wise.

[corax]

Why do you want more? There shouldn't be any reason to dial in more advance than it's capable of now -> more advance = more likely to have spark knock = ECM retards timing anyway

[YotaFun]

Why do you want more? There shouldn't be any reason to dial in more advance than it's capable of now -> more advance = more likely to have spark knock = ECM retards timing anyway


what he said :P

[partsman93274]

I'm just power hungry. Been reading alot of websites where people have advanced almost 20 degrees to get some extra juice out of their 22re. I know I would have to be careful of knock but I think I'll just leave it alone.

[YotaFun]

if you want power out of your 22re, cam it and turbo it....

[corax]

If someone told me they advanced base timing to 20 degrees, and got any noticable gain, I'd try to sell them on the fuel efficiency of "the Tornado" or using a magnet on their fuel line to break up hydrocarbon molecules for a better burn. Researching ideas like this and asking questions is what leads to knowledge and a better understanding of how it all plays together - just remember, if you heard it on TV or the internet it must be true.

here's some light reading from Wikipedia/ignition timing (http://en.wikipedia.org/wiki/Ignition_timing)

Timing advance is required because it takes time to burn the air-fuel mixture. Igniting the mixture before the piston reaches top dead center (TDC) will allow the mixture to fully burn soon after the piston reaches TDC. If the air-fuel mixture is ignited at the correct time, maximum pressure in the cylinder will occur sometime after the piston reaches TDC allowing the ignited mixture to push the piston down the cylinder with the greatest force. Ideally, the time at which the mixture should be fully burnt is about 20 degrees ATDC. This will utilize the engine's power producing potential. If the ignition spark occurs at a position that is too advanced relative to piston position, the rapidly expanding air-fuel mixture can actually push against the piston still moving up, causing detonation and lost power. If the spark occurs too retarded relative to the piston position, maximum cylinder pressure will occur after the piston is already traveling too far down the cylinder. This results in lost power, high emissions, and unburned fuel.

[partsman93274]

Check out the distributor from LC Engineering. They tell you to set it at 30 degrees (yikes). Thanks for the responses though. I prefer to asking before doing.

[corax]

Check out the distributor from LC Engineering. They tell you to set it at 30 degrees (yikes). Thanks for the responses though. I prefer to asking before doing.


That's total, not base timing (base timing is set at idle with any timing advance diabled). They specify base timing at 10-12 degrees, which isn't far from stock base timing (just a few degrees off at most)

LC Engineering Pro Distributor (http://www.lcengineering.com/TechNotes/index.php?techid=87)


We recommend running a total timing of 28°-32°. LC Distributors provide 20-22 mechanical timing advance at 2000 RPM. Set the initial timing (engine running below 1000 RPM) at 10°-12°. This will produce 28°-32° of total timing at 2000 RPM. We recommend using a delay timing light to set total timing. Run engine at 2500-3000 RPM when setting total timing with a delay light. For LC Pro Distributors with Vacuum Advance, remove and plug vacuum hose before setting the initial timing.

[X-Tool Pimp]

I run my timing at 25-28 at idle but Im also running propane not gas :hillbill: