Tuning the Tenacious Turbo

Many people often forget that our title is Muscle Mustangs & Fast Fords and when we feature cars other than Mustangs, some people get irate and send us hate mail. But being the true hotrodders we are, we can't neglect anyone's superb effort to go faster, no matter what they drive.

Our Ford Focus project car, better known as the Red Hot Chili Pepper, seems to fall into this category, but we have to tell you that it's just as much fun as the rest of the machinery around the office. Packing a potent Precision Turbo and engine turbo kit and a whole lot more horsepower than stock, our little fully loaded, automatic tranny-equipped, five-door holds its own on the street. We even outran one of those newfangled 240-hp Mazda RX-8s recently, and went door handle to door handle with a Porsche Boxster. That's some pretty good company to keep and it's enough power to make those Mustang and Firebird folk think twice after we holes hot them off the line in our unsuspecting commuter. It becomes obvious when driving the Pepper that we run with a different crowd, but we're working our way to the top in their arena, and are in the hunt for bigger game as the project progresses.

The answer to our stalling problem lies in the disconnected mass air meter pictured here. Chris Winter of Crazy Horse Racing relocated the functioning meter and topped the tube off with a dummy plate to seal it up.

While nitrous was nice for the track (and the occasional squirt when traveling to lunch), turbocharging the Ford Focus has been very rewarding. After Crazy Horse Racing installed the Precision kit, we had some stalling and hesitation issues that really put a damper on the project. Try as we might to go into the computer and tweak the throttle position and mass air sensors, it just wouldn't fix the problem.

We called the main parties involved. Precision Turbo told us it took some time but they were able to solve the problems through the computer. We also worked with Superchips as the Focus software is relatively new to the market and we had turbo tuning wizard, Job Spetter Jr., look at our program but ultimately, it was Crazy Horse proprietor, Chris Winter, who persuaded us to relocate the mass air meter to quell the stalling problem.

Chris split the three wires that make up the air charge temp sensor harness and added a pigtail...

The turbo kit places the meter after the turbo and intercooler in a blow-through position and we wonder if the air isn't stalling in the tract, thereby preventing the mass air meter from getting a reading. Regardless, a few hours and a few small parts later and the Chili Pepper was running perfectly. Putting the meter before the turbo in a draw-through configuration required us to make a few minor but important modifications to the mass air meter's wiring harness.

...to connect to the new sensor, which he mounted in the intake elbow.

The Focus, as well as the '03-up Mustangs have the air charge temp sensor (ACT) built into the mass air meter. After separating the air charge temp sensor's wiring from the mass air harness, Chris wired it to a '99 Mustang ACT unit that he mounted in Precision's cast intake tube. This will accurately read the incoming intercooled air and allow the computer to adjust timing and fuel appropriately. Chris has made a similar modification to the '03-up Mustangs that are to be supercharged.

The air filter mounting tube needed to be cut down in length to provide room for the mass air meter. This was easily accomplished as there was plenty of material to work with.

The mass air harness also needed to be lengthened so the meter could be stashed in the fender at the head of the intake tract. We've mentioned in past stories that we switched to an SVT meter (from our GMS unit) that could cope with the increased airflow. Chris pulled the SVT piece from Precision's installed location, filled that with a dummy meter top to seal the intake, and then placed the SVT meter in the GMS housing and bolted it to the air filter. Attaching the SVT meter to the beginning of the intake tract required cutting the supplied tubing down to allow the meter to fit into the fenderwell. Thankfully there was plenty of metal to work with.

(Dyno Graph) After the mass air meter was moved, Chris put the Pepper on the dyno to make sure all was well. To our surprise we lost 10 peak hp, but gained 5 lb-ft of torque. The crazy graphs are due to the automatic transmission and Chris's efforts to roll into the throttle so as not to make the transmission downshift.

With just a few hours of work, the Focus was purring like a kitten. Winter put the Pepper on the chassis dyno to verify that the air/fuel ratio was in check and he made a dyno pull as well. We were actually down slightly on horsepower but up in torque. The Pepper previously made 167hp/195tq, but after the meter movement, the turbocharged in-line four put down 157.7 hp at 6,100rpm and 200.4 lb-ft of torque at 3,400rpm, the latter of which would really help us at the track.

Yes, the dragstrip. We finally were able to get some quarter-mile times after all the time and effort and our first track outing of the year proved to be quite fruitful. If you've seen any sport compacts at the drags, you've probably noticed that they do one of two things. They spin the tires like mad at launch or they bog horribly, both of which nets bad 60-foot times. Thanks to the near-instant boost and available torque from the turbocharger, the Chili Pepper does neither. Careful modulation of the loud pedal would evoke a few chirps from the Nitto rubber and then it was off to the races.

Our first track day of 2004 brought great results. The Red Hot Chili Pepper has been simmering all winter and was plenty potent having improved from our naturally aspirated e.t. of 16.90 to a peppy 14.56. We also added 13mph to our trap speed at the same time.

The Chili Pepper's best naturally aspirated e.t. was 16.90 at 79.99mph, this with a 2.40 60-foot time. On the jug, the Focus went 14.92 at 90mph with a 2.22 short time. The turbocharged five-door went 14.97 at 93.94mph on an unprepped track surface. We followed that up with a 14.66 at 92.82mph. Sixty-foot times were 2.37 and 2.20 respectively. We then had the Raceway Park staff spray a little VHT down and dropped the hammer to a 14.56 at 93.20mph. Having a few runs under our belt and some improved traction let us cut the short time to 2.18 seconds.

The Precision Turbo kit has knocked nearly two and a half seconds from our elapsed times and added 13mph to our trap speed. And best of all, there's no bottle to fill. The power is there whenever you need it at onramps, in the passing lane or at stoplights. Next, we need to get some gauges to monitor our boosted condition, and we're looking into a limited slip for even more traction. Stay tuned.