Curiosity concerning the use of Hondata's 4 bar MAP

FlashPro questions & answers specific to the 2007-2008 Acura TL
Post Reply
Posts: 36
Joined: Thu May 16, 2013 10:10 pm

Curiosity concerning the use of Hondata's 4 bar MAP

Post by Yungone501 »

Had a thought the other day while tuning and figured I'd try and gain some clarity here...

My previous engine was boosted but current engine isn't (yet). I'm using the Hondata 4 bar MAP sensor from previous boosted setup on my N/A engine and after some thinking, realized this may not be a smart decision. I'm aware that the MAP sensor sends a 0-5 volt signal back to the ECM depending on engine load (vacuum/pressure) but noticed that FlashPro asks specifically which MAP sensor is being used in the calibration. Assuming the scale is read differently (0-5 volt signal) between the listed sensors, this would mean running the 4 bar sensor may give me decreased sensor resolution accuracy if being used on a N/A motor that will only ever see vacuum. Would this be correct? Would the tune be more precise on a factory Honda MAP sensor over the 4 bar?

Also, I know I'll never see a "zero" vacuum during WOT but what's an ideal vacuum reading to see (or maybe a range of what NOT to be seeing) from an engine that's breathing without restrictions? The general consensus seems to be around 1.5" but that sounds a little high to me. I'm aware that engine design and dynamics play a massive role in an exact number here but I'm just looking for an idea.

Thanks in advance for the help. :)

User avatar
Site Admin
Posts: 18603
Joined: Fri Sep 20, 2002 5:06 pm
Location: Hondata

Re: Curiosity concerning the use of Hondata's 4 bar MAP

Post by Spunkster »

You are correct that the scaling is changed a bit by using a 4-bar, but it should still work without causing you any problems. There are still enough breakpoints that the ECU can read and it is still very accurate. You could always just put an OEM sensor back in and use that instead.

Post Reply