Penny-Pinching Power Parts For Your Pony

This month, Muscle Mustangs and Fast Fords is all about going fast on a budget and picking performance parts that are cost effective, so we grabbed hold of our recent 5.0/AOD bolt-on Pony and threw some tried-but-true performance parts at it.

Our subject vehicle, a slick little notchback, had been mostly track tested until now, but we had to throw it on the dyno to get some results, as our local tracks here at MM&FF South were closed for a couple of weeks during the holiday season. That being the case, we loaded up the coupe and headed for Orange Park, Florida, a small suburb of Jacksonville and home to HP Performance, where we planned to pound out the horsepower on its Dynojet dynamometer.

Our 5.0 Mustang always responded well to the simplest of modifications, and today, we're looking to improve the 302's breathing through some choice induction and valvetrain mods. As far as bolt-ons go, our coupe has seen its share. The AOD-equipped ride has a 3.55:1 ring-and-pinion upgrade, a full performance exhaust from the headers back, a Cobra intake manifold, Ford Racing Performance Parts underdrive pulleys, and a K&N panel replacement filter in addition to advanced initial ignition timing. We're also running 150 hp worth of nitrous at the dragstrip, but for these tests, we'll keep things au naturel, as we're looking to bump up the engine's performance with only gasoline.

That being said, we decided to open up the induction side of things with a bigger mass air meter, a larger throttle body, and a set of higher-than-stock roller-rocker arms to move the valves a little more.

We found out by utilizing the Dynojet's wide-band air/fuel meter that the coupe was running rather rich for a naturally aspirated car (about 11.6:1), which was certainly hurting power a bit, as well as mileage. We thought the new meter might lean things out, but it wasn't enough, so HP's Tony Gonyon whipped up a little program and loaded it onto a chip for our A9P automatic processor. The added timing did the trick, and we picked up even more ponies.

Installation-wise, the throttle body and mass air meter were rather simple and easily accomplished by the beginner. The roller rockers require a bit more technical knowledge, but if you can pull off your upper intake manifold, it shouldn't be too difficult. Figure about three to four hours for the novice, or less than one hour for someone who knows his/her way around the 5.0 Mustang engine bay.

Within this article, you'll find some interesting information from C&L Performance's Lee Bender, who provided us with pictures and test results from his custom flow bench on which he develops C&L's product line. C&L's proprietary computerized flow stand, which is capable of not only measuring the capacity of entire high-performance air-intake assemblies at a full 28 inches of depression, but it's also used to generate mass airflow calibration information for its different aftermarket upgrade MAF housings and complete intake assemblies for the newer applications. Bender also gave us some insight to the C&L meter, along with installing it on our car.

"Our calibration is intended to be used with a high-flow filter in the stock airbox assembly," Bender says. "This calibration was developed on the dyno to create the maximum power with a stock computer tune and a normal fuel pressure level." That being said, it stands to reason that vehicles equipped with adjustable fuel-pressure regulators set outside of the 40- to 42-psi static range may have their air/fuel ratios influenced by those factors.

"The stock air/fuel ratio typically hovers in the 11.8-12.2:1 range, and removing the stock airbox assembly and replacing it with a cone air filter on the end of the stock mass airflow body will result in a MAF calibration/signal that is 10 percent leaner," Bender says. The 76mm unit was designed to deliver an air/fuel ratio that is within the ideal range, and graphing the output of this unit is virtually identical to the stock MAF with the cone filter attached on the end.

"Installing a cone filter on the C&L piece could lean out the air/fuel ratio to a range that is leaner than ideal, resulting in an air/fuel ratio that will not deliver maximum power," Bender says. He noted that this would not cause you to run lean enough to be "concerned," but simply leaner than it needs to be for maximum power. Adjusting the fuel pressure can help to counteract this effect, but C&L recommends the panel assembly for best overall fit, finish, and convenience.

Check out the captions to see how our round of penny-pinching power parts performed, and be sure to check back as we've been looking at cylinder-head options and plan to get back to the track as soon as it opens for the '08 season.