what is better using a map sensor or a mas. i am just wondering. dont plan on trying to convert. i was just at dsmtalk.com and they are trying to convert to gm 3bar sensors. can someone please shead some light on this subject

 

the supra guys are also converting to map over on the AEM EMS forum. i have a basic understanding of Mass Air Sensing, but it sounds kinda ghetto.

MAP (manifold absolut pressure) seems to be a better choice for tunability. i dont know enough about Mass air to tell you why its not as good. but apparently it sucks.

 

the only thing i can think of is the fact that the map is limited to 3bars. but i dont know for sure if 3bar is the biggest map made. i know having a map allows you to vent into the atmosphere the only benefit to that is it sounding cool.

 

huh?

 

with a metered air flow system, you have to vent the BOV back into the intake after the MAF because the air has already been metered.

 

if you dont you will run rich and bog down

 

Yep, volkswagons do that. I think there called diverter valves. Now a long time ago this vw guy said that there better but had no idea why.

 

True, but is this really a bad thing? I guess you do lose some nice sounds in the process.

 

wish honda could get a VPC like the supras

 

First off.. VPC stands for Vein Pressure Converter. It's only purpose is to convert Mass Air Flow systems (MAF) to Speed Density systems.

Why is that important? The MAF sensor is a specifically engineered restriction in the intake air stream that measures how much air volume passes through it and at what temperature. This tells the ECU how much O2 is available to burn fuel. It is a very simple and accurate way of determining fuel needs. But it is also very restrictive when you double your airflow needs (larger turbo) and can rob you of power very quickly.

With a Speed Density system, there are no ECU required restrictions in the intake system. It is only necessary to use engine RPM and Manifold Absolute Pressure (MAP) to determine fuel needs. Unfortunately this requires knowledge of the engines ability to breathe at all RPM and MAP points (volumetric efficiency).

So basically, the VPC converts systems with inferior tunability to a more superior system like the one in your Honda. Then they still have to figure out their volumetric efficiency and buy even more **** to fix the problems with the VPC (Hence the GCC). If you have ever tried to tune a DSM with "every piggyback" available, you would understand.. Just like the VAFC on Hondas, the VPC is a band-aid approach to true engine managment for MAF equipped cars.

 

I believe that MAS systems work by having a heated element in the air intake that changes resistance with temperature. So, the more air that flows through, the quicker the element cools and the less resistance it has, so the computer knows to add fuel. I understand that this type of system is better for an NA car, since it can keep adding more fuel with modifications. A buddy had a 12.0x sec NA mustang with the stock computer because it just knew that a TON of air was going through there and it needed more fuel. (He ran low 11's, high 10's with a big shot of N20, with the same as well) I'm not sure it would work that well with boost, however.

 

A good article I just found:
http://www.sts.sae.org/membersonly/t...s/article5.htm

 

i bet there are alot of people that still have there temp sensor hanging out side of the intake. acording to this article it is use to calculate the density of the air.

 

It's not...

http://www.aempower.com/bbs/viewtopic.php?t=168