Any timing experts out there that can explain some some timing paremeters

[1970-CST]

Originally Posted by Rickysnickers

Here is the engine I am running, https://blueprintengines.com/product...lock-bp4002ct1 . I have the ECU set to idle at around 850 rpm. As per the Edelbrock instructions, the initial timing is set at 12 degrees. This is set for the firing of the injectors and that they are firing correctly. The distributor included with the fuel injection is all electronic. There are no vacuum lines to it at all. The timing and vacuum advance is done through a tablet.

From the specs of the engine it says 32-34 at 3500 rpm. That’s a pretty lazy timing curve, but that is where I would start, as it is what the engine mfg recommends.

The tabled has the ability to do you want.

12 initial plus the 15* in the vac advance setting. Will give you 27* of idle timing

If it pings or knocks when you punch it, you can back the initial to 10, or 8 and add 2-4 to the vac adv setting to make it 17-19. You want no less then 20* TOTAL idle timing. I would shoot for 24-28.

[Rich72C10]

gee, glad we got that sorted out! I suppose I could have said "its a MAP sensor" does that make a difference?

[Rich72C10]

I know we gotten straight on the MAP sensor, vacuum and pressure stuff. Yesterday during our confusion I had emailed Progression Ignition and I thought I'd share his reply. Since it is nice to have someone actually take the time to respond with details.

Originally Posted by Theodore@Progression Ignition

The first thing to know is what the units mean. Kilopascals kPa is a unit of PRESSURE. The sensor we use is an absolute pressure sensor. It will tell you the ACTUAL pressure in the intake manifold. Vacuum is not an absolute measurement. Vacuum tells you the DIFFERENCE between the pressure outside the intake (atmosphere) and the pressure inside the intake. This is the most common misunderstanding. As an engine tuner you want to know the actual pressure as this is what determines how long it takes for the fuel to burn. Also, vacuum readings DO NOT compensate for changes in altitude. The timing table in the app is set up so that high pressure is at the TOP of the screen. At wide open throttle, there is no restriction to the air coming into the intake manifold. Therefore, you will see atmospheric pressure at WOT. At sea level, atmospheric pressure is approximately 101 kPa. This is why the top row is 101 kPA. A naturally aspirated engine won't go higher than this. The bottom of the timing table is 20 kPa which is low pressure (high vacuum). You will only reach this level when the throttle blades are closed and RPM is high during deceleration. As manifold pressure DECREASES from WOT (top row), the fuel needs more time to burn because the fuel/air molecules are becoming further apart from one another. This is why more timing advance is needed at low pressures. You are starting the burn sooner to allow the fuel to burn completely before the crank descends too far down the cylinder.
So as far as the app settings are concerned, here is what they mean. Using the standard settings of 8, 80, 20. Max vacuum advance- this is the max number of degrees that will be added at the max vacuum point of 20 kPa. Start vacuum advance at- this is the pressure level at which degrees will begin to gradually be added. This is just under WOT which is good for street drive cars. Remember low kPa=high vacuum.

[Rickysnickers]

Ok, thanks!