Installing a 2 bar MAP sensor on a 5.3,does it need to be placed after the blower to read pressure and is the right part PN# 16040609 2bar MAP

 

This is the part number from an earlier thread.... GM part 12580698 (AC Delco #213-1631)

I need to order mine, so hopefully someone can confirm.

 

Yep, that the right PN. It's a direct replacement for the stock MAP, but you do have to adjust the tune for it or it won't run.

It does need to be on the pressure/vac side of the intake

 

What is the "pressure/vac side"??? doesn't it get installed installed where the MAP is in the Radix manifold? And what needs to be adjusted for the tune? I understand the adjustments when moving to speed density, but, if i am tuning w/ the MAF, won't the tune just see it as a 1 bar sensor?
Thanks!

BTW, I just ordered mine earlier this week (GM part 12580698) and I want to just swap mine out and leave the tune alone until the move to SD.

 

also btw...i paid $49 from GM parts direct (including shipping) I hate that place, but it is the only place i could find it.

 

don't you need some special tuning software for it to work? like HPtuners 2 bar upgrade?

 

yes, it replaces the factory sensor. Do not istall it untill you tune at the same exact time. It will not run right if you dont have it tuned for it. You can tune for it not using 2 bar software by tricking the computer by dividing the #'s in half. It isn't the best way to do it due to the computer being slower to respond or some crap like that. Maybe some of the more tunning savy guys can explain this a little better. I'm just repeating lip service

 

Stock MAP location on the radix is fine. But you MUST have the PCM changed for it whether it be HPT 2bar, EFILIVE or mail order. If you just put it in, it won't run. The voltage reading from the 2 bar MAP are half what the stock MAP are, so the PCM will not make the correct fuel calculations. That's how it can read 2 atmospheres with the same 0-5v output.

 

You will have to change the MAP sensor scaler in the tune. Here's an excerpt from the EFILive tutorial. Not sure about the HPT procedure for doing this.


Configuring a 2 or 3-bar MAP sensor

When the key is on but the engine is not running, the MAP sensor reads the barometric air pressure, usually 101kPa (14.7psi). When tuning in high altitude areas it is worthwhile reading the MAP values (using EFILive’s Scan Tool) at key-on with the standard 1-bar sensor to obtain the barometric pressure at the current altitude.

After fitting your 2 or 3-bar MAP sensor, you must rescale the MAP sensor.

Engine Diagnostics->MAP->Parameters


• {C6301} MAP Sensor Scaler: 2-bar sensor: 190, 3-bar sensor: 288


These values will get the MAP scaler’s value close to what it needs to be, you will then need to adjust it (by small amounts) until the MAP sensor reads the same barometric pressure that your standard 1-bar sensor was reading at key-on, engine-off.

 

More info on this please. I will be doing it shortly....

Does 2 bar allow your PCM to calculate for boost better?
I was told that with a stock 1 bar you either are getting fuel at the rate you get while in vac (-20 to 0) OR WOT full boost fueling even when only at part throttle or part boost because the PCM doesn't know the difference in 1# vs. 10#'s. A 2 bar map will allow for a more efficient fueling system because it can read from -20 vac to +15psi? So a 2 bar won't just dump full boost fuel in when its only at part boost. Make sense? How far off am I?