Boost Signal for MSD

[Norm K]

I’ve locked my distributor in order to be able to take advantage of the 6530’s boost and ignition retard features. Part of that process was, of course, disconnecting the vacuum advance to the distributor. My question is this; will the vacuum line that formerly went to the distributor provide an adequate/appropriate signal for the MAP sensor?

[totle]

I would say that the connection has too small ID to be able to used as connection to MAP sensor.
But it might work

[Tippy]

I would think you are fine. The nipple on my MegaSquirt is uber tiny and my car is 100% MAP.

[proffighter]

Used the port on top without issue on my SDS EFI for MAP. Port at the bottom is used for BOV

[fredmeister]

Originally Posted by nkowi

I’ve locked my distributor in order to be able to take advantage of the 6530’s boost and ignition retard features. Part of that process was, of course, disconnecting the vacuum advance to the distributor. My question is this; will the vacuum line that formerly went to the distributor provide an adequate/appropriate signal for the MAP sensor?

Use an unported signal or a port that is below the throttle plate at all times. There should be a tap available on the throttle housing that you can tee into for the MAP sensor.

It does not need alot of flow it just needs to get a pressure signal so small diameter hose should be fine.

Make sure you are using a 3bar MAP sensor for the MSD because you need vacuum as well as boost signal and anything over 1 bar boost requires a 3 bar sensor.

Please post pictures of your MSD reetard curves when you get them programmed so we can see what you are running and comment how it works in the engine.

thanks,
Fredmeister