BBK Shelby GT500 Throttle Body - Tech Inspection

Are two blades really better... 

   

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Are two blades really better than one? We're installing this BBK Power-Plus Twin dual-blade, 65mm throttle body on an '08 Shelby GT500 (that makes nearly seven-hundie at the tires with a mono-blade throttle body, by the way) to see what, if any, differences there are in dyno performance and driveability.

We really hope those of you who own Shelby GT500s have been faithfully reading 5.0 Mustang & Super Fords for the latest news and details on the cool upgrade components available for the special-edition 'Stangs you're fortunate enough to have parked in your driveways (including Editor Steve Turner). While we've pretty much covered all of the elaborate, Shelby-specific engine, drivetrain, suspension, and appearance parts that are currently being sold, testing bolt-on throttle bodies (which, ironically, are a lot simpler than other Shelby products we've told you about) has been uncharted territory... until now.

Installing and evaluating the performance differences (recorded in baseline and post-install tests on a Dynojet chassis dyno) between a mono-blade, 66mm x 160mm piece and BBK Performance's new Power-Plus Twin, a 65mm, dual-blade throttle body for Shelby GT500s (PN 1764; $319), is only one of the agenda items for this edition of Tech Inspection. While the larger, single-blade unit is a major player in the pursuit of achieving maximum power-as evidenced by the stout 662.46 hp and 663.40 lb-ft of torque we recorded during our initial dyno run-the big-mouth 'body has been a minor hindrance to tuning the Shelby's potent combination for smooth idle and good driveability. Our mission with this tech effort is to see whether improved, non-WOT street manners can be tuned into our potent test Shelby using BBK's budget-friendly, CNC-machined, twin-blade throttle body. We also want to see how close the 'Stang can come to it's all-out mono-blade performance on the dyno once the piece with two holes is in place.

As you'll see in the small assortment of photos, the bolt-on aspect of this project is beyond do-it-yourself easy. However, tuning must be handled by an experienced pro using a chassis dyno and the appropriate tuning software, SCT's Advantage III in our case. The results were stock-like driveability and mono-blade-style performance.

Installing the new throttle...        read full caption Installing the new throttle body involves only a few simple hand tools (needle-nose pliers, 1/4-inch-drive ratchet w/ extension, 1/4-drive 8mm and 10mm deep sockets, T-20 Torx socket, and a 5mm Allen wrench). The first order of business in setting up the new throttle body is to remove the mono-blade 'body (or OEM piece if you're working with a stock Shelby) and swap the plastic-capped throttle spring, TPS, and motor housing onto the BBK unit. Then, using needle-nose pliers, rotate the plastic-capped spring 180 degrees to align its mounting tabs with their landings on the motor housing, and lock it in position.

The BBK throttle body secures...        read full caption The BBK throttle body secures to the intake manifold with two supplied Allen-head screws on top and the factory nuts on the bottom.

Once the intake tube and PCV...        read full caption Once the intake tube and PCV tube are reinstalled, our throttle-body swap is a done deal...in approximately 10 minutes.

As you see here, power and torque with the BBK twin-blade throttle body is pretty much on par with the big steam that our test 'Stang made with a mono-blade 'body attached to its intake. The big difference is in low-rpm street performance and driveability. The BBK piece allows us to easily tune out the low-side "chugging" that is a byproduct of aggressive components like the mono-blade throttle body, and even high-rev camshafts installed in a force-induced engine.

Our final results for this exercise are favorable street manners with only a minimal impact on power. We're sure an actual rear-wheel performance gain will result from installing a Power-Plus Twin on a stock Shelby GT500, which makes it a good bolt-on to consider if you're about to modify or are already making upgrades to make your good 'Stang better.