Mass Air Sensors

test

Written by David S. Wallens

 

Vane-type air flow meters are simple and effective, yet they are often seen as a bottleneck when trying to increase performance. Tuners say they block the incoming air, while they their lack of adjustment can be a problem on a modified engine.

Eager to see what kind of gains could be made, we converted two cars from air flow meters to more modern setups--our Miata project received the Flyin' Miata/Link Programmable ECU while we went with Split Second's MAF kit on our E30-chassis BMW M3. Both systems were basically plug-in-and-play setups for the respective car. As a bonus, both systems allow additional tuning.

Both installations were done at Atlanta's Engineered Performance under the eye of dyno tuner Ed Senf. Watching Ed tune both systems made us realize how a knowledgeable dyno tuner can make or break a project. Additionally, Rennie Bryant from Redline BMW Performance helped with the M3 conversion.

All 1.6-liter Miatas (1990-'93 production) use an air flow meter, which the Flyin' Miata/Link Programmable ECU replaces with a manifold absolute pressure sensor (MAP). Where the air flow meter uses a hinged air vane to determine the amount of incoming air, the MAP monitors the amount of manifold air pressure and converts that figure into a voltage signal. This signal is sent to the car's computer to determine the proper amount of fuel and ignition.

The Flyin' Miata/Link Programmable ECU replaces the stock ECU board, while the supplied MAP sensor plugs into the stock wiring harness. The system has an "auto tune" feature, although further tuning was done at Engineered Performance on their Dynojet chassis dyno. The Flyin' Miata/Link Programmable ECU allows full control over fuel curves, timing curves, rev limit and so on.

In addition to the parts included with the Flyin' Miata/Link Programmable ECU (ECU board, keypad, MAP sensor and instructions), we also added a Flyin' Miata knock sensor, four-wire oxygen sensor and Injector Air Fuel Ratio Monitor from Racer Wholesale Parts.

And now for the M3

Our 1988 BMW M3 received a slightly different conversion, as it lost its air flow meter and gained a mass air flow sensor. A mass air flow sensor (MAF) uses a heated wire to measure the amount of incoming air. The more electricity needed to keep the wire at the desired temperature, the more air that is going into the engine. This information is sent to the car's computer, which determines the necessary amount of fuel and spark needed at the moment.

The Split Second MAF kit for the M3 includes the mass air flow sensor, wiring harness, air intake tube, ARM1 air-fuel ratio meter and ARC2 Air/Fuel Ratio Calibrator, a four-channel control box regulates low, mid, high and acceleration levels, working with the stock BMW computer.

We'll cover all of the details in the December issue of GRM, but we won't keep you in suspense forever: Both systems helped us make more power, and neither one was particularly hard to install. We would say tuning them on a chassis dyno is a requirement, however. Adjusting knobs or punching buttons while driving down the street at wide open throttle isn't exactly safe.

Join Free
Join our community to easily find more BMW articles.

Reader comments:

You'll need to log in to post.

The Latest

What Do You Get When You Cross a Modern Honda and a Vintage BMW?

2 days ago in News

Find out in the next issue of Grassroots Motorsports.

2017 Nissan Armada Platinum

2 days ago in New Car Reviews

The Nissan Armada is the brand's largest non-commercial vehicle and is a direct competitor to Chevy's Suburban and Ford's Expedition. ...

Tech Tips: 2015+ Ford Mustang

3 days ago in Articles

How to make it your way.

Speciality Insurance for Our Special M3?

3 days ago in Project Cars

Can you save 15% or more with Hagerty?

First Drive: 2017 Subaru BRZ Performance Package

4 days ago in Articles

We’ve heard it before: The Subaru BRZ doesn’t make enough horsepower.

10 Cars to Buy Now

5 days ago in News

Hagerty recently announced the top 10 classic cars to buy in 2017.

Reader's Ride of the Week: Cone-Killing Camaro

5 days ago in News

This one's a work in progress, but we can't wait to see the finished product.

Get Our Magazine in Print and Digital for just $17.99

5 days ago in News

Now is a great time to renew or start subscribing to our magazine.

Treading on Thick Ice

5 days ago in News

How do you improve your car control in the racing off season?

Strap In

1 week ago in Articles

Is your racing harness installed correctly?

2017 Volvo XC90 T6 AWD Inscription

1 week ago in New Car Reviews

Volvo's XC90 is the manufacturer's luxury SUV and this—the T6 Inscription—represents the highest tier of that model. And to triple ...

Flyweight Flier

1 week ago in Articles

The masses may not view the Mazda2 as much of a sports car, but enthusiasts have learned otherwise.

Grassroots Motorsports Magazine

Subscribe Today

Also get your instant access to the digital edition of Grassroots Motorsports Magazine!

Learn More
DytfWSbOmmmuL5ZCh7pcr8vuCkyM2imk