Taking a little time off is often a good thing, and in the case of PHR's Project Mustang, it's been a great thing. For a few months, it was crazy around the Tech Center, scheduling what modifications would come next. Taking a little time to think through what really needed to happen next helped us to come up with better plans and more isolated testing.
Rather than make huge, expensive changes right away, we focused on making a little power under the hood that could be easily replicated and afforded. Thanks to three simple systems from BBK Performance Products, we nailed it. The results were amazing, not in that they made giant power but that they made big gains for such basic modifications. Moreover, each of the changes will make for a better package as our modifications get deeper. Each system retails for under $200, so that's a big plus!
The parts here are all very basic bolt-ons, performed with common hand tools in your driveway (and that's a rarity these days). The first thing that we took on was the pulley, BBK Performance Underdrive Pulley Set, for 2001 and up 4.6L GTs and Cobras (PN 1559). The system slows down the front accessories just enough to give you back some power but not so much as to cause cooling or electrical issues. Included are aluminum replacement pulleys for the alternator, water pump and crankshaft, with the latter being the only tricky one to install (it presses on after a bath in hot water). If you would have told us that we could get almost 12hp and over 12lb-ft more at the rear wheels from just this swap, we would have told you that you were nuts! The DynoJet proved it, as did the seat of the pants feel. We ran a few 20-minute road course sessions at a NASA Track Day in Las Vegas with this setup and saw no cooling rise or voltage drop. So if that's not an endorsement, we don't have one for you!
The next to find its place was the throttle body, the most basic swap of all. We often get letters asking why the OEMs don't sell vehicles with bigger throttle bodies in the first place (if they help to make so much power), and the answer is expense.
Look under the hood of various makes, models, and years, and you'll see that they often share a similar setup. When they build your new GT (or GTO for the GM set), the cost savings is important right down to pennies, both in terms of their profit and your final purchase price. A custom throttle body for each vehicle would cut into both, and that's why a stock Mustang GT has a 65mm unit in place. Now BBK does sell a Throttle Body Assembly for the 1996-03 4.6L 2V GT (PN 1700), but it's designed for when it's about the only thing you're going to change. So we went with the 75mm unit (PN 1701). We found a little better throttle response and a gain at the rear wheels of 4.3 hp and 3.3 lb-ft. Not bad, but I'm sure it'll show its true colors once we get that ProCharger system on board. If we get time, we'll try the blower kit with the throttle body to show you just what we mean.
Finally, we strapped on the BBK Cold Air Induction System for 1996-'02 4.6L GTs. It is one of the better looking systems that we've seen, not to mention that it made the most dramatic appearance change so far. This new part (PN 1718) replaces the factory air box, increases under hood noise a bit, and actually makes it sound like a little as if you have a turbo when you step on and off the gas. The system comes with a real K&N filter and its fender well intake insures that the air is as clean and cold as it's going to get without a bunch of plumbing. We achieved a gain of 9.8hp and 13.2lb-ft of torque on the chassis dyno with this final install, but we think the throttle body really started working better once this cold air system was in place--the two work together.
Overall, we went from making 225.5hp and 263.2lb-ft to generating 249.2hp and 263.2lb-ft with the three bolt-ons working together. When you consider a 15 to 20 percent loss from the flywheel horsepower ratings that is incredible.
We took the Project PHR Mustang out to "Fontucky" for a little testing and the results were a great surprise. California Speedway's parking lot is wide open, and that's where we did our baseline tests, so know that traction is a little limited on launch. Initially, our stock 4.6L SOHC GT (with the Maximum Motorsports suspension system, and K-member already on board) could only muster a 15.17 in the quarter at 93.02 mph, but with our bolt-ons we went 14.42 at over 98 mph! That is a serious increase for such simple mods, friends. Our 0-60 mph increase was significant, too, as we went from 7.09 seconds down to 6.12 seconds!
These numbers should drop dramatically again once we get BBK's longtube headers and crossover pipe on board. Let's not forget the Magnaflow exhaust system, either. We were going to install new COMP camshafts after that, but it looks like the ProCharger system is going to be next. We'll have to remove the cold air system to make the blower arrangement work, but we'll be adding a Superchips custom chip and a Granatelli Motorsports mass air meter, which should really wake this thing up!
Check back next month to see what ends up on this car next.
BBK Performance Underdrive Pulley Set, for 2001 and up 4.6L GTs and Cobras (PN 1559), is one of the most surprising installs we've done at this magazine in a long time. By slowing down that accessories run on the serpentine belt, we achieved almost 12hp on the chassis dyno.
The crank pulley is the only tricky part of the install, as you'll need a puller to get the old one off the crank and you'll need to soak that new pulley in hot water. That'll expand it enough for the clearance to press onto the old pulley. Be careful and get it on all the way--this is an example of how not to do it, as it needs to be completely flush.
Sorry, but this is about all you can see of the pulleys when they're installed. Forget who cool those aluminum pulleys could look if you could see them--they work better than we could imagine. We experience no noise and the stock belt worked fine.
BBK's 75mm Throttle Body Assembly for the 1996-03 4.6L 2V GT (PN 1701) didn't show us the gains we hoped for all by itself, but we think that the following cold air system install worked together with it to generate a serious increase. BBK is a leader in this area, with many GM designs, too.
This stock throttle body is 65mm, a serious restriction when you start making changes like we have planned. We robbed the throttle position sensor off this one.
The BBK Cold Air Induction System for 1996-'02 4.6L GTs (PN 1718) is a relatively new part in their catalog. In terms of appearance, it makes about as big of a difference is you could make to an otherwise drab look. It made 9.8hp and 13.2lb-ft of torque on our DynoJet.
Sure looks better than when we started. With a gain of 23.7hp and 29lb-ft, we're not only looking cool, but we're going faster. Wait until we get all of the exhaust and the blower kit on board, as it'll make these changes look small. Mission accomplished, however, and each of these parts will continue to make more power as we help elsewhere.