Using a SMALL plenum for the vacuum is a requirement - not an option - otherwise you have nowhere to take the MAP reading. There is very very little vacuum signal from these types of intakes. I would advise you to use the plenum for ONLY the MAP signal. I was trying to remember - but think I could only get 4 or 5 inches of vacuum reading at my plenum. The pulse signal is soooooo weak without having a large common plenum of the dual plane / single plane intake....
To help tune the idle circuit -- in the efi maps -- you make smaller incremental
grids in the idle vacuum and rpm map.... then you can tune out the lumps easier with finer control... and also using the idle spark add or subtract.
IMHO, a guy that's GOOD with these ECU EFI systems can make anything/combo run like a swiss watch.
I just finished helping a buddy with his 8 stack (Imagine Injection) install - using Fast XFI on his 454 big block. It started the FIRST TIME - in about 3 rev's - once I tweaked the distributor timing to actually match the ECU - it purred... and there's nothing like the sound of air being gulped one cylinder at a time.
It's not my car - it's a buddies... so I hate to say too much about the car other than it's the straightest '56 I've ever seen.... and the paint is a mile deep... It has a cream leather interior... AND my arms nor hands showed any dirt after helping him with a bit of wiring and fuel lines...
Brian Hobaugh SCCA National Tour June 2014
First Hemi 'Cuda Convertible Ever Built
Short clips: Goodguys Pleasanton autocross and pit videos
Linear Mode
