With everyone involved in the automotive industry always striving to get the most bang for their buck-the best mileage they can and the most power to boot-a lot of worthless products have been put on the market in the last decade. We're not pointing fingers, but some pretty hokey mystery fluids and air swirlers plague the automotive aftermarket, and its tough to figure out what really works and what you're whizzing money down the drain on. And it gets even trickier, because some products work really well on some engines, while others...well, you'd be better off spending the money on carbon-fiber rearview mirrors because that would have helped just as much.
 F&B has multiple throttle...  F&B has multiple throttle bodies to choose from, but we went with a 2x52mm unit meant for mildly modified 5.2L and 5.9L Magnum engines. The body is a one-piece machined billet-aluminum unit with stainless steel throttle shafts and smooth rounded edges ramping into the 52mm bore. F&B's kit also comes with new stainless steel Allen screws to bolt in your original sensors from the factory throttle body. If you have more than 60,000 miles on your ride, F&B suggests replacing the sensors. |  The factory throttle body...  The factory throttle body (TB) can be removed in about three minutes. A couple of vacuum lines and a few wiring harnesses need to be disconnected, and the factory TB will lift right off the manifold. Before we removed the factory TB we did a couple of dyno runs on the Dynatech dynamometer to compare with. At the peak, we made 257 hp at the rear wheels. |  You can certainly see why...  You can certainly see why it might improve the airflow path into the engine over our factory throttle body. Unlike cheesy aluminum castings, the machined billet-aluminum almost guarantees no cracks or pit holes in the body of the TB. All surfaces are coated with a clear sulfuric anodized coating, while the butterfly plates are cut from 6061-T561 aluminum and open on ABEC high-speed ball bearings. We were just hoping that it would work as well as it looked. |
 The factory sensors are reused...  The factory sensors are reused on the new F&B throttle body, but with new hardware. Stainless steel Allen screws are supplied to add the sensors onto the new TB. |  Once we had the sensors on,...  Once we had the sensors on, we bolted the new F&B throttle body into place on our intake manifold. A few minutes later, we had the truck back on the dyno to get another few rolls out of it and see what happens. F&B suggests turning the engine on and off once or twice before you drive so the ECU can get used to the difference in airflow at idle over the old TB. |  With the throttle body install...  With the throttle body install finished (in all of about 15 minutes), the truck was thrown back onto the dyno at The Dyno Shop. Mark Macneil hooked up a T-fitting inline on one of our vacuum hoses to tell if there was a difference in the amount of vacuum into the engine (Macneil did this for our stock TB as well). If the engine had a little less vacuum, then it would prove that the new throttle body was actually allowing more air to flow into the engine. |
What about throttle bodies? They are pretty pricey pieces of metal, but we've heard that if ported correctly, they can be a really nice addition to your engine. But how can they help so much? Throwing a performance carburetor on top of an engine will net you some fantastic results, but they flow the fuel to your engine as well as regulating the airflow.
We wanted to put the infamous performance throttle bodies to the test, so we called up F&B Performance, one of the better-known and highest-quality throttle-body manufacturers we know. F&B agreed to meet us at The Dyno Shop in Santee, California, to bolt one onto our recently running (again) red '94 Dodge. What we didn't tell F&B was that this truck was notorious for making stuff not work right and that the engine had already had a lot of flow work done to the manifold and heads. We knew it was going to be hard for the new throttle body to give us anything at all.
Boy, did we give F&B a challenge to overcome. Not only was this engine not stock, but it was our Jinxy truck to boot. If something could go wrong, it was going to go wrong. Mark Macneil of The Dyno Shop verified that F&B had brought Magnum-engine-equipped vehicles to them in the past and proved gains of 7-8 hp with an F&B TB. With that said, we spun the tires on the dyno and got our numbers. The vacuum in the engine did in fact drop just a little bit, proving better airflow. At the peak, we did in fact see an increase of almost 3 hp to bring our total to 259.4 hp at 5,164 rpm. Through most of the rpm band we made 4-5 extra hp.
But driveability is the real test. We went out for a ride in our Dodge and found what would be the real selling point for the snazzy throttle bodies-the responsiveness. The gain of a few horsepower was not too noticeable, and the fuel economy increase wouldn't pay for the throttle body for many thousands of miles, but the responsiveness of the pedal sold us on the idea that performance throttle bodies are worth it.