The installation of a DynoMax after-cat exhaust system was only part of our complete exhau
BBK's 1 5/8-inch shorty headers come complete with new gaskets and header bolts. They're a
DynoMax's after-cat exhaust systems for Mustangs are staples in the exhaust aftermarket. W
One of our friends recently traded his '01 Mustang GT Bullitt and supercharged '65 Mustang coupe for a '74 DeTomaso Pantera--the fantastic Ford-powered, mid-engine Italian exotic you rarely see these days. However, once that transaction was complete, he was left without a daily driver to commute back and forth to work as a county sheriff's corrections officer.
Still an avid Mustang lover (even though he now owns that radical Pantera), his dilemma was solved in the form of a creampuff '95 Mustang GT coupe he scored for the screamin' price of $5,200. And since the car was 100 percent stock, it serves as the ideal subject car for a series of sensible but effective upgrades that will make it more fun to drive on the street.
Since our buddy's SN-95 5.0 also represents the final year of pushrod 5.0 production, it's an even more interesting car to work with. We decided to begin with the installation of a complete exhaust system, which in our case included a set of BBK shorty headers, a BBK two-cat X-pipe, and a DynoMax after-cat exhaust that includes mufflers and tailpipes, all of which are available from California Mustang. A solid, well-proven combination that resulted in a mellow but still authoritative tone, we also wanted to test the setup on a dyno to see what power gains might be achieved even though the car was otherwise bone stock (see sidebar).
There were issues with the car that had nothing to do with the parts we installed, so our results weren't what one would expect. But we pressed forward, knowing we could correct the car after the system was installed.
Furthermore, we had the pleasure of working with X2C Motorsports, a competent late-model Mustang performance shop in the Los Angeles area. The techs at X2C made it look easy, having the whole system on the car in well under four hours, even though we stopped them often to photograph the installation.
1 Unlike many cars, including vintage Mustangs, installing an exhaust system on a late-mo
2 Next, unbolt the front of the H-pipe from the stock manifolds by removing the flange nu
3 Once the stock H-pipe is separated from the manifolds and mufflers and unbolted from th
4 With the stock H-pipe out of the way, removing the stock mufflers and tailpipes takes o
5 With the stock mufflers separated from the tailpipes, the system is removed easily by s
6 Removing the stock exhaust manifolds is next. The X2C techs begin by removing this car'
7 On the driver side, remove the oil dipstick tube and all spark-plug wires. You might ha
8 Although not required for the header installations we've done on Fox Mustangs, disconne
9 Next unbolt the manifold from the cylinder head. On an SN-95 5.0, the manifold drops ou
10 To access the manifold, disconnect and remove the air-injection hoses on the passenger
11 On an SN-95 5.0, access to the passenger-side manifold is surprisingly good once the a
12 Installing the new components is a reversal of the removal process for the headers, X-
13 Like the removal, installation of the driver-side header on an SN-95 is easiest by sli
14 With the headers installed, fitting the BBK X-pipe is next. Although the air tube is c
15 The X-pipe can now be installed by hoisting it into place. Installation involves conne
16 The DynoMax after-cat system is a direct replacement for the stock mufflers and tailpi
17 The mufflers attach to the mid-pipes and tailpipes with the supplied muffler clamps. I
18 This is the complete after-cat and X-pipe installed on our '95 5.0. We headed off to t
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.
BBK Headers, BBK X-Pipe, and DynoMax Exhaust System