We always used to laugh at the dyno shop and say that we wanted to take all the “As seen on TV” type of performance parts and install them all to see if they actually made any power improvement. And I don’t mean one at a time. So if one part says it makes 20 horsepower and the other says 10 and another says 15, then if we install them all it should make 45 more horsepower right? Probably not. But that doesn’t mean that simple bolt-ons won’t make a power improvement, or that they won’t help you make more power after other modifications. Let’s take a throttle body for instance.

Whether fuel injected or carbureted, a naturally aspirated engine will make maximum power when it receives the maximum amount of air and fuel that it can physically ingest. An LS engine, for example, will use whatever air and fuel is can suck into it and that is going to be based on the airflow capabilities of the engine itself. Those are based on compression, cylinder head flow, intake flow, camshaft specs, throttle body size, etc. If the throttle body, or carburetor, is too small and doesn’t allow all the air into the engine that it wants, then it won’t make maximum power. If the throttle body does allow all the air it needs, but the injectors don’t flow enough fuel, then it won’t make maximum power.

But why would the manufacturers not install a throttle body, injectors, cylinder heads, etc that will support maximum power? Cost, performance goals, etc, all have an impact on what comes on the engine from the factory, so those parts are not usually designed for max performance efforts.

This is why bolt on components can add more power than factory, in a lot of cases without breaking into the engine itself.

So when can you expect a gain in horsepower from changing out a throttle body? And do they always make more power?

Video Description:

SHOULD I UPGRADE MY STOCK LS THROTTLE BODY? DO BIGGER THROTTLE BODIES ADD POWER? HOW MUCH POWER IS A THROTTLE BODY UPGRADE WORTH? DOES A BIGGER THROTTLE BODY ON A SMALLER INTAKE OPENING REALLY WORK? WHEN SHOULD I INSTALL A BIGGER THROTTLE BODY? DOES A BIGGER THROTTOLE BODY ADD POWER TO A POSITIVE DISPLACEMENT SUPERCHARGED LS? IS A THROTTLE BODY UPGRADE NECESSARY ON A TURBO OR VORTECH SUPERCHARGED LS? CHECK OUT PART 1 OF WHAT’S IT WORTH WHERE I DEMONSTRATED THE POWER GAINS OFFERED BY THROTTLE BODY UPGRADES ON A STOCK 4.8L LS, ON A 383 STROKER AND ON A TVS SUPERCHARGED 5.3L. FOR GREAT DEALS ON LS PERFORMANCE, CHECK OUT richardholdenerperformance.com.