S197 V6 Mustang Bolt-On Test

Because cars don't run around... 

   

  read full caption

Because cars don't run around with their hoods up, we tried a few runswith the hood down to see if the cold-air kit would lose any efficiency.It did as heat built up. However, the airflow around through the enginecompartment isn't the same on the dyno as it is on the road.

Ricardo said cold-air kits and underdrive pulleys are the big V-6sellers, so we opted to install the cold-air kit next.

GTR provided a C&L kit, which uses the larger mass-air housing (itreuses the stock electronics as C&L's always have), larger intake tube,a large open-element air filter, and a DiabloSport's Predator electronictuner with an upgraded tune optimized for the cold-air kit.

In fact, there are various tuning options in the Predator, notably onefor 87 octane and another for 91 octane. We switched back to 87 octanefor our first try with the cold-air kit. We were rewarded with a solid6rwhp gain. Considering there can't be much, if anything, from ignitiontiming with the Predator's 87 octane tune, we have to chalk most of thisgain up to increased breathing.

The less-restrictive, open-element air filter and smooth intake elbowcasting is the main source of gain from the cold-air kit, as indicatedby the increased induction noise through the filter. It makes an easilyheard, but not overly loud "tuuuuff" sucking sound when you mat theaccelerator.

At this point, we did a side experiment with the hood. Open hoods arethe rule on chassis dynos because it helps shed heat, which is always anissue with the car stationary and making long, hard pulls, regardless of how many fans are pointed at it. But cars don't run down the road withtheir hoods open. With the cold-air kit's air filter sealed to the hood,running with the hood open means the air path to the filter is unusuallywide open, and mainly fed by fanned shop air to boot. Deciding we'd liketo see what happens when the hood goes down, we made several pulls tostabilize the engine temps and output at "good-and-warm," then ran somehood-open, hood-closed, hood-open tests. The result was a repeatable 3rwhp drop in power with the hood closed, so engine heat or airrestriction is a factor when chassis dyno testing.

We ran the remainder of the tests with the hood open for cooling andcontinuity with our previous tests.

Next, we reinstalled 91-octane fuel in the gas tank and switched to the91-octane tune in the Diablo Predator. This picked up 3 rwhp and 3.5lb-ft of torque, both measured a little higher in the powerband. This isa predictable power gain, as the higher octane allows more ignitiontiming, which is one of the surest paths to power.

DiabloSport Predators supplied...        read full caption DiabloSport Predators supplied with the C&L cold-air intake arepre-programmed with C&L-specific tuning. All of the other Predator'sfunctions remain intact. GTR offers the Predator by itself at $385.99.If possible, purchase the C&L intake kit and Predator in one package, asit is $60 more ($674.98) to purchase the two items separately.	Smoothing bends and eliminating...        read full caption Smoothing bends and eliminating the chaos-inducing folds of bellows aresure paths to increased airflow. C&L's cast-aluminum intake elbow doesboth.	C&L has long championed the...        read full caption C&L has long championed the now common practice of using the stockelectronic mass air metering element in an enlarged housing. Thus theC&L cold-air kit includes a larger diameter mass air housing to acceptthe stock meter. The required special tamper-resistant Torx head bitwith recessed center is provided by C&L.
Installing the C&L cold-air...        read full caption Installing the C&L cold-air intake is nothing out of the ordinary. Theintake tract from the air filter box to the throttle body is removed andreplaced with the C&L parts. Here, Ricardo Topete removes the stockmass-air metering element from the stock plastic intake tube/air filterhousing.	The stock mass-air element...        read full caption The stock mass-air element is reinstalled in the C&L meter housing. Onlytwo screws are involved, but they are the tamper resistant type of Torxhead fastener, and the bit provided by C&L saves everyone a trip to thehardware store to procure this esoteric tool.	Getting air to the new open-element...        read full caption Getting air to the new open-element air filter is done by boxing in thefront corner of the passenger side engine compartment. The plastic airdam traps incoming air, and more importantly, helps block hot underhoodair.

Looking mighty shiny is MAC's... 

   

  read full caption

Looking mighty shiny is MAC's Direct Fit Muffler kit. It's a $169.99combination of muffler and tailpipe. The bright look is courtesy of theunit's stainless steel construction. MAC figured that since Ford'smuffler is stainless, all of its '05-'06 mufflers would be stainless aswell.

Mufflers are a popular bolt-on, mainly because of the noise. On the newMustang, the mufflers are all the way at the rear of the car and blessedwith high-quality, reusable clamps. Ideal for changing, in other words.

Ricardo produced a MAC axle-back kit, which is the muffler andtruncated, large-diameter tailpipe attached. The installation takes afew minutes, as there are three hangers involved, along with asmall-mass damper (oh, those weight-loving engineers).

Once Ricardo finished hanging the muffler, the engine had had a prettydecent cool-down. We weren't expecting much, if anything, from themuffler as far as power was concerned, as with cats and relatively lowpower to begin with, there simply isn't any meaningful restriction inthe stock mufflers these days. For once, we were right. The mufflerdidn't really change anything relating to power, as the "gain" is withinthe margin of error on this test.

On the other hand, fitting the V-6 with a blower, nitrous, turbo, orother air-mover and the muffler might be worth some power. It would alldepend on how much air is being pushed out the tailpipe.

But if the power didn't change with the muffler, the sound certainlydid. The stock V-6 muffler is a quiet one, and the MAC is not. The soundis definitely V-6, with a bit of a rasp. Ricardo said it sounded like ahopped-up Nissan 350Z, and that was a great call. If you like the higherpitch V-6 buzz with a bit of tear in it, you'll dig the MAC.

Activating the pre-programmed...        read full caption Activating the pre-programmed tunes in the Diablo is easy stuff, asRicardo demonstrates. There are plenty of opportunities for customtuning as well.

There are three hangers on...        read full caption There are three hangers on the V-6 muffler which are transferred fromthe stock muffler to the MAC replacement. It's wrench and socket work,and will take a few minutes as you wrestle a bit with the hangers andensure the muffler hangs straight. The MAC is raucous, emitting ahealthy six-cylinder rip.

This weight suspended on a...        read full caption This weight suspended on a tuned rubber bushing is a mass damper. Itsmission is to cancel vibration by vibrating out of phase with theundesired vibration. They work, but add to the overall weight of thevehicle, so you might want to experiment with and without them. Thisdamper is on the exhaust pipe; there is one on the muffler as well.