
We went to the pros at Granatelli...

We went to the pros at Granatelli Motor Sports in Oxnard, California for our replacement meter and went with its 70mm unit, designed for the '00-02 Focus. It is calibrated for the factory 19-lb fuel injectors and can be used with or without the factory air box and filter arrangement. We chose to scrap the stock and restrictive air box for an open-element filter included with the meter.

The stock air box is not designed...

The stock air box is not designed with optimum airflow in mind and can be extremely restrictive at higher rpm due to a series of baffles in the lower portion of the box, which are there to help quiet the incoming air stream at higher rpm.

The OEM filter is made from...

The OEM filter is made from paper and lays flat in the top portion of the air box making it inferior to performance.

For the first modification,...

For the first modification, we slapped on an open element (cone style) air filter to see if the factory 58mm meter could benefit from a better breathing filter. With just a filter swap, we gained 3.2 hp and 3 lbs-ft of torque.

Next we removed the factory...

Next we removed the factory mass airflow sensor. Crazy Horse Industries owner Chris Winter removed the electric plug from the top of the sensor before loosening the clamp on the factory inlet tube.

After loosening the hose clamp...

After loosening the hose clamp on the tube, the mass airflow sensor can be lifted out from its position.
For some time now, we have been hinting to you Focus enthusiasts that our very own Internet project machine, "The Red Hot Chili Pepper," will be receiving a dynamite and extremely necessary turbo kit from Precision Turbo and Engine. We actually have the kit on hand and will be tackling the install next month (October, '03) but for now, we'll take the easy route to performance by upgrading the factory mass airflow sensor with a 70mm unit from Granatelli Motor Sports in Oxnard, California. This simple mod should give us a few extra ponies and will become a welcome addition when the turbo is finally strapped under the hood.
When we first received the Infra-Red 5-door, we blasted it with a host of bolt-on goodies. A Focus Central 65mm throttle body improved our intake flow and a Focus Central equal length, 1 5/8-inch shorty header with a full 2 1/4-inch, mandrel bent stainless steel exhaust system from Magnaflow dramatically improved the exhaust tone.
As for looks, the original rim/tire combo was tossed in favor of a set of trick Konig Blatant Opal dubs, which roll on high performance Nitto NT450 18-inch tires. We also have a 75hp nitrous kit from Nitrous Express residing under the factory hood, which dipped us into the 14-second zone at over 90 mph.
One component we never thought of trying out, however, was a simple mass airflow sensor upgrade. Along with lower (numerically higher) rear end gears and maybe an aftermarket short-throw shifter, a larger mass airflow sensor is usually one of the first items most Mustang owners embark on but we, sadly, never took that into consideration with our Focus.
With the small-in-size 2.0-liter ZETEC engine under the hood, you can bet your bottom dollar that more airflow is what this mill needs and we hope that a larger mass airflow sensor will become beneficial in the quest for more power. The factory mass airflow sensor on the Focus measures in at a minute 58mm while the Granatelli Motor Sports unit is noticeably larger at 70mm. The meter also comes with its very own open element, cone style air filter, improving the overall flow and breathing of the engine and helping to add horsepower.
"We sell a wide range of larger mass airflow sensors for all types of vehicles and offer a 70mm unit for the '00-02 Focus," explained Dennis Sorensen of Granatelli Motor Sports. "The sensor is a duplicate of the unit found on a 4.0L Ford Ranger truck but is calibrated for use on the Focus. It retails for $367 and should add a fair amount of power to a normally aspirated engine combination. With a power adder you may see even more."
In order to find out what type of gain we would see we stormed over to Crazy Horse Industries in South Amboy, New Jersey and began with a generous engine cool down before making a few base runs on the in-ground Dynojet. With the stock air box, filter and meter aboard we mustered a best of horsepower figure of 97.0 and 102 lbs-ft of torque. Not bad but not mind-bending either.
We were down in horsepower slightly from past dyno pulls but the weather was extremely humid, which may have caused a slight fluctuation in our readings. Nevertheless, we had our base numbers but before jumping into the Granatelli meter we tried slapping on an open element air filter to the factory Ford meter.
The stock air box is rather restrictive and not designed with optimum performance and airflow in mind. It has baffles in it designed to keep the incoming air charge entering the intake tube as quiet as possible and the factory air filter is made from low quality paper and not very effective to high air speed. To our surprise the open element air filter raised the bar to 100.2 horsepower and 105 lbs-ft of torque. We are well aware of the benefits of a non-restrictive air filter but were still surprised with the 3.2 hp and were eager to strap on the larger meter to see what might become of it.
After removing the OEM meter we connected the open element air filter to the Granatelli unit and after another lengthy cool down we spun the dyno rollers once again. With the new meter and high performance filter we rounded out the day with 101.3 horsepower and 108.2 lbs-ft of torque at the front wheels. The meter/filter combo was worth a solid 4.3 hp and 6.2 lbs-ft of torque, which is approximately what we were expecting.
Next month we promise to finally install our turbo kit and hope to dip into the high 13-second zone without hitting our 75-hp nitrous kit. We'll then bite our lip before attempting to run both power adders in an attempt to bust into the low 13s. Will our in-house Focus become a low 13-second player or just another on-track casualty? We'll find out next month.

The factory meter bolts to...

The factory meter bolts to the top portion of the stock air box and is held in position with two long screws. An orange o-ring wraps around the inlet portion of the meter and seals out unfiltered air.

The Granatelli Motor Sports...

The Granatelli Motor Sports meter is noticeably larger than the stock unit and should flow a handsome amount of air, especially when our turbocharger upgrade takes place. The actual sensor (inside the unit) is stock but calibrated for the larger inner size of the meter.

After connecting the Granatelli...

After connecting the Granatelli Motor Sports meter to the inlet tube, we bolted on the supplied open element, cone style air filter and let it rip once again on the Crazy Horse dyno.

We have hundreds of pulls...

We have hundreds of pulls on the chassis dyno and, for the meter swap, we again flogged everything out on the dyno. When dealing with minute modifications it becomes difficult to record your gains on the racetrack.

For consistency and the best...

For consistency and the best possible horsepower readings, we used this electric fan to cool the engine between pulls. Within 10 minutes the engine was below 160 degrees and ready for action.

With the factory meter, air...

With the factory meter, air box and filter, the Pepper came in at a conservative 97.0 horsepower and 102 lbs-ft of torque.

By doing nothing more than...

By doing nothing more than replacing the air box and filter with a cone style, open element one we jumped to 100.2 horsepower and 105 lbs-ft of torque.

Finally, with the Granatelli...

Finally, with the Granatelli Motor Sports meter we finished the day with 101.3 horsepower and 108.2 lbs-ft of torque. The meter, no doubt, worked but the stock meter with the open element filter gave us the biggest surprise.