Time and time again I talk to people that are doing an LS Swap, or have an LS Powered late model car, who rattle off some parts they are going to upgrade to “make more power”. Headers, exhaust, cold air kits, and throttle bodies seem to be on everyone’s list and no matter what I say they always look at me funny when I tell them that a throttle body is a waste of time and money. Sure, there are times when a throttle body might be needed, on say a bigger engine that has been outfitted with a larger intake manifold. But in most stock style builds, including those under boost, there is no real need to increase the throttle body size. But before you tell me I’m full of it, check out the video below as proof.
When Speed Secrets’ Richard Holdener did the test, back to back, on the engine dyno, the results speak for themselves. Watch the video and let us know what you think. And feel free to tell us what other parts you’d like to see tested, because we can probably make it happen. There are tons of things we can test, and we’d love to do what makes you happy.
In this episode of Speed Secrets, we test whether installing a larger diameter throttle body than your intake port opening really gains power! This highlights the importance of matching modifications together to create the most benefit. Parts used: F.A.S.T. Big Mouth Throttle Body: (part #54103 and #54091) COMP Cams 54-469-11 LSr Camshaft F.A.S.T 65lb/hr Fuel Injectors (Part #30657-8)
This is absolutely a waste of time. No duh a 102 mm bolted to 92 mm opening doesn\’t do anything. Now bore out that opening and blend it into the plenum, and you might have a real test.
You just restricted the air flow from 102 to 92. How about doing the same test with a lsx 102 intake or port the stock intake.
I have a 90mm throttle body and plan on running the lsx Intake. Would like to see if upgrading the throttle body is worth the money.
A 102mm TB into a 92mm opening is not a bright idea, a Darwin Award for sure.
You people are missing the point! Their point is those people who buckle and dime there engines believing the hype of “10-15 horsepower gain!” of the components they buy. They see the hype and believe “WOW! If headers give me 10-15 hp gain, cold air intake gives me 10-15 gain, TB will give me 10-15 hp gain, throw on some Holley, MSD, and FAST stickers, then I should get 30-45 more HP!” They don’t understand on what engine package or RPM range those gains were accomplished. They were merely proving to those “nickel and dime” people, buying a bigger TB for a stock engine does NOTHING.
And at what rpm does it make this extra HP. You can\’t run 5000 rpm every where you go!
I understand what was being accomplished here. It was a basic education on fluid dynamics. From an obvious point of view. Yes all you experienced LS lovers out there knew strapping on a 102 TB on to a 90mm intake would result in a 90mm outcome. As a little twister a FAST intake was thrown in for fun sake. If putting the dollar to HP/Torque bang for the buck. The FAST intake with the 102mm TB. will give you a gain. But nothing Comared to a Supercharger. For example take Matt and George. Both have an LS376/480 in their rides. Matt has a modified pro stock car. Where George has a 2500 Pickup. Matt want to lower his 1/4 ET. George wants more Torque going up a grade while towing 9,000 pounds. And decent fuel economy at highway speeds. So is a supercharger the best solution for both?
Is a FAST Intake with a 102mm TB the solution. Obviously not. Turns out for NALSE Normally Asoerated LS Engines. The greatest contributor to Torque for George is the runner length inside the intake. Is where George will obtain the most Torque. Which is what George needs. So as it turns out. There is already a truck intake that will provide more Torque for George that is found on the L9H 6.2L engine. It is an oddooking intake in that it is much higher than the FAST intake. Almost twice as tall. Giving a much lo longer runner from the Throttle Body into the Engine. There by increasing Torque. George\’s Torque range is pretty much flat over the rpm range. This and coupled with the factory cast iron exhaust manafold and a 4 inch cat back system. Where Matt on the other hand. Will benefit from a Supercharger, headers and a large cat back system. So what we have here is an example of accomplishing a set goal. Of Horsepower versus Torque. Of course there are other factors that affect both. Those being Transmission and rear end gear ratio. So to meet your goal one must consider both air and mechanical with the goals in mind to accomplish the task for the vehicle.
Lingenfelter tested a tb they ported on a 383 build-got 8 hp up top. I have one they ported for $100. Throttle response is instant. Probably not worth spending a few hundred unless you’re hoi.