How To Install a 5.0 Exhaust System

13 Like the removal, installation...        read full caption 13 Like the removal, installation of the driver-side header on an SN-95 is easiest by slipping it into place from underneath the car. Using the supplied new gaskets and hardware, start all the new header bolts before final-tightening the new headers in place on the engine.	14 With the headers installed,...        read full caption 14 With the headers installed, fitting the BBK X-pipe is next. Although the air tube is clamped to the stock H-pipe, we decided it would be easier to cut off a section of the air tube and join the tube and new X-pipe with a piece of the correct-size small radiator hose and hose clamps.	15 The X-pipe can now be installed...        read full caption 15 The X-pipe can now be installed by hoisting it into place. Installation involves connecting it to the new headers with the supplied hardware and reversing steps 1 through 3.
16 The DynoMax after-cat system...        read full caption 16 The DynoMax after-cat system is a direct replacement for the stock mufflers and tailpipes. The mid-pipes that connect the mufflers and X-pipe are the first to go on. These pieces are joined together with the supplied hardware.	17 The mufflers attach to...        read full caption 17 The mufflers attach to the mid-pipes and tailpipes with the supplied muffler clamps. It's a simple and effective setup, and the X2C techs called the DynoMax package "a nice kit that fits well." With everything started, the clamps are tightened up with an air ratchet or a standard hand ratchet. The DynoMax system is adjustable, allowing you to move the components around to eliminate rattling or rubbing. Look out for tailpipes rubbing the rear tires and pipes rattling against the car's floorpan. Once these areas are checked, all nuts and bolts can be tightened to finish the installation.	18 This is the complete after-cat...        read full caption 18 This is the complete after-cat and X-pipe installed on our '95 5.0. We headed off to the dyno, and had mixed results because our subject car wasn't where a stock 5.0 should be.

Reality Dyno Testing

The original idea behind this how-to was to show what a good-quality exhaust system would do for power improvement on a stock but well-maintained 5.0. Our intentions were honest and the BBK and DynoMax components are certainly worthy of any enthusiast's consideration. The problem was, our test car was a dog and way down on power long before we installed any parts. We didn't have the time to troubleshoot the car before our scheduled baseline dyno-testing on the Los Angeles Performance Division's Dynojet.

This '95 5.0 was detonating on 91-octane pump gas with only 9-10 degrees of initial timing, which was the root of the problem.To keep the engine from detonating into oblivion on the dyno, we had to run the timing at a seriously retarded 8 degrees initial with 91-octane gas.

By the time you read this, the owner will have likely solved this issue. Something was definitely amiss since we were forced to have the timing so retarded that the car made only 172 hp at the rear wheels for a baseline, when we would've had at least 190-200 hp to start with using 10-12 degrees of initial timing. Even though the car was that far off, the exhaust system was still worth 12hp peak improvement at the rear wheels.

We told the folks at BBK what we experienced. They surmised the exhaust system on a healthy car would be worth a solid 20 hp or more at the wheels. We agree, and the exhaust system, combined with other airflow improvements such as an intake manifold and cylinder heads, will make a bigger difference as you climb farther up the horsepower ladder. When this car is fixed, we plan to retest it and report the results to you in a future issue.