Timing

[rstare]

Okay so my friends keep asking me about the timing once im turbo'd. A 4g63 guy i know says he advances the timing one degree for every extra pound of boost. Now I thought I read in maximum boost that you need to retard timing once you start adding boost. Anyways I know our cars dont need to worry about timing until about the 18psi mark (at least thats what I have heard) but could someone explain why to me? I havent really gotten into the whole timing thing but all my friends keep asking me and I dont have a real answer for them. So enlighten me my friends.
Thanks

[Shadow98]

You DO NOT advance timing with boost! Doing so will cause detonation/ knock and you can say good bye to your motor. Detonation is cause by premature ignition of the fuel, creating an explosion in your cyclinder before it reaches TDC (top dead center). If I remember correctly, at 17+ psi is when you need to start retarding your timing on pump gas.

[rstare]

This is exactly what I thought. So why is it that we (being 420's) dont have to retard timing as soon as 1psi comes into the picture?

[Locke]

Mild factory timing maps, relative to other NA motors found in sport coupe's.

Rich factory fuel map, relative to other NA motors found in sport coupe's.

Offset pistons roll off knock's shock much better than 0 offset pistons.

Factory pistons, while considered weak by 4g63 standards, can handle a fair amount of knock.

A knock sensor, which pulls time when knock is detected.

[Slippi84]

Originally Posted by rstare

This is exactly what I thought. So why is it that we (being 420's) dont have to retard timing as soon as 1psi comes into the picture?

I think you meant DO not don't and it's because those cars(ECU) were made to be boosted and it's already been accomidated for. 420a's have totaly different timing maps and in such advance timing more than a 4g63 will at higher rpms. Hell simply how the cars meter air is different. Our cars use IAT and MAP sensors while 4g63 cars use a MAF.

Edit: yes like locke said the knock sensor is a big part.

[rstare]

Thanks Locke, that helps alot.
I know this is the 420a forum, but how do 4g63 guys deal with adding boost? Is there a point where they have to start retarding timing?

Originally Posted by Slippi84

I think you meant DO not don't and it's because those cars(ECU) were made to be boosted and it's already been accomidated for. 420a's have totaly different timing maps and in such advance timing more than a 4g63 will at higher rpms. Hell simply how the cars meter air is different. Our cars use IAT and MAP sensors while 4g63 cars use a MAF.

Edit: yes like locke said the knock sensor is a big part.

Slippi, I did mean dont. What I was saying was that 420a's dont have to retard time at all till 18psi. I figured the timing would be more advanced on a n/a so once boost was added then the timing would definatley have to be retarded.