2 Bar or 3 Bar MAP Sensor

[TGP37]

OL and CL deals with how much fuel to add into the metered air. To use open loop, unplug the o2 sensor or disable closed loop with your tuner by setting closed loop temps at 280F.

Speed Density and MAF deal with the calculation of air entering the engine. To use SD, unplug the MAF or disable it in the PCM.

You can run open loop with SD or MAF. Same as running CL with either SD or MAF.

With open loop you can command whatever AFR is in the Open Loop Table. It comes at the price of not having the O2 sensor to keep the idle at 14.7:1 AFR. In closed loop you WILL idle at stoich (14.7:1) while still able to tune the AFR in power enrich mode (floor it).

Both have their pros-cons.



You should read up on the operation of the PCM before attempting to tune it. Failing the MAF won't put you in open loop. It will put you in Speed Density. Unplugging the upstream O2 will put you in open loop.

[ChevyBlown]

question i'm running the stock 1 bar map but my car isnt making boost at 100kpa so should i increase the max_map from 100 to like 160 or can i run 2 bar settings on my stock 1 bar map?

[3400-95-Modified]

No you can not run 2 bar settings on a 1 bar map... That's just a dumb question the sensor is limited to not reading boost.

[ChevyBlown]

i know it not gunna read boost i was just wondering if i can scale the values so i get a more accurate reading until i actually get into boost

[3400-95-Modified]

When you adjust the scale your getting a LESS accurate reading... There is no way to get more accurate pre boost than what you already have.

[TGP37]

Accuracy isn't an issue really because the points are just data points, the pcm determines the value between them.

A straight line can have 2 points of resolution or 24 points of resolution, the data stays the same.

It is the changes, the curves in the VE Map (and other tables) which need the resolution but transient is best fueled properly with AE and DE where most that stuff is.


Best thing you can do is not trick the PCM. If you want reliable performance, befriend the PCM and give it what it needs to work properly. Get a 2 bar map, or 2.5 bar.