Throttle body spacer

[Nosho47]

Has anyone ever used the volant or any other throttle body spacer? I have a 4.8 tahoe and just looking for small mods for now. Is it worth getting? I had a throttle body spacer in my 01' s10 and I felt a difference with the acceleration. I am also try to get more mpg...

 

[Gzes]

Alot pf people say its no real gain. I thought about one for my 5.7 but i dont have themoney to just buy stuff that wont do anything noticably more

 

[LTLux]

Does nothing for newer engines but make a nice whistle sound.

Do a search in here, there are a ton of posts about it.

 

[imi4tth3w]

i have one but for the only reason that i got it for free.. they do nothing but make a sweet turbo sound yeah yeah

 

[doubletapdrew]

I had one on my 92 5.7L TBI Yukon. It boosted the low end torque noticeably but seemed to kill some of the top end.
On my 02 5.3L silverado I added one of those VaraRam velocity stacks. I don't know what that did because I put on a magnaflow cat-back and diablo tune at the same time.
I'm sure if you were handy with a dremel you could port the factory throttle body and get the same or better results for free. Thats what I did on the camaro (along with the bumpstop mod and coolant bypass). Seemed to free up a few ponys.

 

[handstr]

my volant doesn't make any sounds.. i thought something was wrong with it.

 

[stevek]

Here's a post I found on another forum to explain why throttle body spacers are a paperweight

I have had several requests to make this short write-up into a sticky so here it is:

Throttle Body spacers sound good in theory but do not work in practice. Assuming the spacer could impart enough spin on the incoming air to bring it to the level of better blending the A/F mixture it would still have to surmount a few hurdles.

First there is the throttle plate itself. In all but wide open applications this plate is sitting at an angle to the incoming air. This is kind of like having something lodged in your windpipe. The intake air enters through two crescent moon shaped openings at the top and the bottom of the throat of the Throttle Body. This means at best only a portion of the intake air is subject to any possible rotational action to be imparted by the Throttle Body spacer.

Second, let us assume that the air does remain spinning after passing the angled throttle plate. Now that air stream needs to be split into 8 separate paths - and mind you these paths are not continuous flow but rather start and stop spurts. As each cylinder draws air in through the open intake valves air rushes down the intake runner into the cylinder. As it does so it rushes past the fuel injector (HOORAY!!!) which sprays fuel into the passing air stream. Hopefully the fuel is sprayed in rather than squirted as the idea is to have the fuel evenly dispersed as a mist in the air stream and not as droplets - as a side note clogged, blocked, or caked injectors result in coalesced fuel droplets rather than an even mist which decreases fuel economy so keep those injectors clean!

Now, back to what is taking place in the intake manifold and runners. The cylinder draws its air and fuel charge and then the intake valves spring shut. The air previously rocketing down the intake runner now slams to a halt. Simply stated, Newton's Third Law encompasses that for every action there is an equal and opposite reaction. Ooops. The air bounces off the now closed intake valves and the shock wave travels back up to the intake manifold where it collides with all the other air milling around in there. This is followed immediately and continuously by the air from the other 7 cylinders. Any spinning imparted by a Throttle Body spacer is systematically pummeled to death by the shock waves created when the air being drawn into the cylinders ricochets off the closed intake valves.

For this reason Throttle Body spacers do not provide improved fuel economy. But the story does not end there.

There are ways to tumble the intake air as it enters the cylinders. A few years back I came across "intake tumblers" while researching a theory of mine. Audi did this awhile back by placing adjustable tabs in the intake runners just before the cylinder head. They would adjust according to intake velocity in order to provide the most beneficial mixing of the air and fuel as it entered the cylinder. They had some problems with the set-up and I am not sure if it was ever perfected but the idea is intriguing. It also brings to mind that any tumbling or spinning should be "tuned" to a particular RPM and Throttle Body spacers being a fixed object are unable to react to or adjust to changing intake velocities. If they did work it would only be in a very limited RPM band - probably in the upper extreme RPM range where things got to moving so fast that each intake stroke of each piston would be so fast as to POSSIBLY compensate for the reverse shock wave created by the intake valve closing.

I have yet to have a manufacturer of Throttle Body spacers agree to provide their product for testing after explaining that I would post the results here in this forum.

---------- Post added at 05:40 PM ---------- Previous post was at 05:39 PM ----------

I had one on my 92 5.7L TBI Yukon. It boosted the low end torque noticeably but seemed to kill some of the top end.

You're full of it

 

[NORCAL SS]

guys get the ported manifold by peak speed shop. I put up pics on my esky and it deff made a nice difference.

 

[doubletapdrew]

You're full of it

I was surprised as I didn't think it would do anything but the butt dyno showed a noticeable boost off-idle to about 2500rpm, but felt like it lost some higher rpm pull. I installed a Jet stage II prom chip first and it woke up the top end a little. Then the TB spacer seemed to boost off-idle torque and cancelled out the improved top end from the chip. It probably just shifted the torque curve toward the lower rpm range, since i never dynoed it.

 

[stevek]

I was surprised as I didn't think it would do anything but the butt dyno showed a noticeable boost off-idle to about 2500rpm, but felt like it lost some higher rpm pull. I installed a Jet stage II prom chip first and it woke up the top end a little. Then the TB spacer seemed to boost off-idle torque and cancelled out the improved top end from the chip. It probably just shifted the torque curve toward the lower rpm range, since i never dynoed it.

Dyno sheets or shenanigans.