Injector Timing

[Rustam]

Hello,

Vehicle: Subaru WRX STI single AVCS

How to calculate and set the most effecient values in this table (injector timing)?

Thanks

[dx4picco]

For the same other settings put different values of injection timming and look at how the AFR are changing.

You would like to chose the injection timming giving le lowest AFR (richer) for everything else staying the same.

[Rustam]

Link Help says that the injection should be stopped just before intake valve is opened.

Is there any option to guess this moment?

[dx4picco]

you need to know the camshaft specs (duration mainly) as well as the camshaft timming on the engine (center lobe position for example)

[Rustam]

Unfortunately I do not have intake cam specs

The only thing I know that they are HKS 264 degrees, 9,1 lift

I've made an enquiry to HKS, but there was no reply.

I've tryed to put different values in injector timing table: 360,400; but I have not seen any changes. However when I've set the value 450, AFR had become richer (INJ timing position  - END of injection).

I supposed that it should have become leaner, or I've mistaken. Why does it happen?

Anyway thank you

[Davidv]

Remember that injector timing only really makes a difference when the injector is open for a very small amount of time. Such as idle or cruising. 

Because once you're up to say 70% or higher duty cycle, your injector is firing for so long that it makes little difference.

I've found that around 400deg is good but on cold starts bringing closer to 250deg (from memory ) meant I could reduce cold start enrichments.

[remski2]

Here is a starting point.

My EJ257 with GSC S2 cams, head work.. and so on...