MSD Hemi 6 question

[Kiddart1]

Quick question regarding MAP sensor plug.

I am running the hemi 6 box and Carb wire harness 04 to 08(#88864) I am also running my Fast EZ EFI system in place of the carb.

Do I use the MAP for the msd box or do I use the MAP for the Fast system?

My gut tells me to use the map for the Fast System and just get a dummy plug for the msd harness. let me know if I am on the right track

thank you all

 

[408 swinger]

I think you're on the right track. But, I would think you would want to make sure to zero the MAP advance on the MSD.

 

[Kiddart1]

that will more than likely be the way I go. I am not a fan of cutting into a harness that can be temperamental to interference. I am still researching so any other ideas are appreciated

 

[myduster360]

I would strongly recommend keeping them seperate.
Use the MSD Map for the ignition and the Fast MAP for the EZ.

Each box will be looking for its own 5v source, signal and ground. If you're not careful , you can get a ground offset between the two boxes which will cause errors in the pressure readings.

 

[Kiddart1]

myduster,
what is your thought on just zeroing out the values for the map on the msd. If I was running a straight up carb I would have noplace to put a map for the msd. or where would I put one for the msd?

 

[408 swinger]

Not to but in, which intake do you have? I have a Ritter and a Prefix. The Ritter was drilled and tapped for a 6.1 style sensor. The Cascar has a hole, but, need to drill and tap the holes for the mounting screws .

 

[Kiddart1]

I have the cascar. it does have a port on the back to be drilled. I can probably drill it myself and use the Map from my truck style intake I have on my shelf. Does that sound like a good solution? this way they both get a signal and neither will interfere with one another.

 

[408 swinger]

Ritter.

Prefix.

 

[Kiddart1]

Nice and easy. I can do that. thank you!!

 

[408 swinger]

I wish I had a good answer. I still think zero'ing the MSD map would work. It's actually used as a faux vacuum advance.

 

[myduster360]

myduster,
what is your thought on just zeroing out the values for the map on the msd. If I was running a straight up carb I would have noplace to put a map for the msd. or where would I put one for the msd?

Run a 1bar MAP sensor with a hose nipple and run it to any available vacuum port. Pretty simple overall