I am using a MSII on my TT Chevy street car. I am using a MSIII on my TT E85 boat. I am familiar with Megasquirt.


I am ready now to put a MS1 on my S4 6 port. I will be running a turbo and E85. I have two stock 6 port intakes. While cleaning them I noticed that the primary runners and secondary runners do not share a common plenum. I am concerned that monitoring only the primary plenum would make it difficult to maintain a consistent tune. Literally you would be calculating your speed density based on 1/3 of the engine (3port throttlebody), leaving the other 2/3 relying on a calculation based off of the 1/3. I have read about thirty speed density posts here with AFR's fluctuating after 2500. I am thinking that the speed density monitoring must be done on a shared plenum.

This only pertains to speed density. A MAF would eliminate this potential problem.

If you are running speed density, which port are you using?

I am considering cutting the plenum divider out of the intake.

 

Use the same nipple the factory does, the nipple on the upper intake that connects to the primary runner. Vacuum signal from that nipple is fine as vacuum is consistent across the entire intake manifold.