Throttle Body Spacers?

Flash12623

Original poster
Member
Dec 3, 2011
44
Are throttle body spacers even useful on the newer 4.3 liters? Seems like they would only be useful if the trucks were throttle body injected which they aren't right?
 

blazinlow89

Member
Jan 25, 2012
2,088
I had a rather long post about this on the OS. No they will do nothing to produce anything useful for practically any engine that is not carb or TBI. In fact you might lose some speed from the extra .4 lbs of aluminum under the hood, be fore you had any real power gains. I am not going on an entire rant about why I feel/know this, but if someone thinks other wise please PROVE me wrong.
 

The_Roadie

Lifetime VIP Donor
Member
Nov 19, 2011
9,957
Portland, OR
I agree. Snake oil supported by no rational physics.
 

Flash12623

Original poster
Member
Dec 3, 2011
44
Ok cool. One of my friends was swearing up and down by them saying they gave his "dang near 10 more hp"
 

The_Roadie

Lifetime VIP Donor
Member
Nov 19, 2011
9,957
Portland, OR
Flash12623 said:
...they gave his "dang near 10 more hp"
A common lie by victims trying to rationalize their hillbilly gullibility. We call that the "butt dyno" effect. Butt dynos are notoriously unreliable and never come with a certificate of calibration. :biggrin:

For more details, see: Butt Dyno [ARSE411] - $399.95 : KaleCoAuto, Hard to find automotive items!

View attachment 19410


Just install a great mod like a cold air intake? Electric supercharger? Big Muffler? Magnetic fuel line ionizer? Awesome wing? Are you getting no respect from your friends for your newly found power? As we all know, these are high end and sophisticated modifications. Some may be TOO sophisticated to actually show up on a traditional dyno. So here we have: The Butt Dyno. Simply place it in the seat, and drive fast, weaving in and out of traffic. (On a race course, of course.) Now you can tell your friends with confidence "That oil-saturated air filter gave me 20 horses!"
 

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burnedfingers

Member
Mar 4, 2012
16
Back in the days of carbs spacers actually worked and the gain was seen on a chassis dyno. Been there done that as I grew up with muscle cars and .25 premium leaded gasoline. The spacer had to be correct as too little produce no gain and too much resulted in a nasty flat spot.

In the age of fuel injection the spacer would add absolutely no gain and probably a loss in power. Computer programs are available that can figure the runner size and length in the intake manifold/s to provide optimum torque, power, and fuel economy.

I finally learned about 19 yrs ago that computers on cars were very handy and usable. I have a 93 Z-28 in the garage with a D1R Procharger on it that produces 18 lbs of boost. Stock cam low compression and mega boost= an easily manageable streetable car with the ability to drive to the strip and run low 10.s
 

burnedfingers

Member
Mar 4, 2012
16
Quote:
Just install a great mod like a cold air intake?

Actually I will disagree with you on this one. Cold air intake like on a 1996 Z-28 SS for example is proven to produce a ram effect in which the computer compensates by making the fuel mixture richer to go along with the increased air and air pressure. There is a proven HP increase in this example as noted by both the factory and published 1/4mi times.

A 1967 Buick Grand Sport 455 is another example of a Factory cold air package that has a marked performance increase. Buick actually pioneered the first truly usable cold air package that worked.

The common bolt on cold air package does little to promote any HP increase but rather decreases it because hot under the hood air does not make for horsepower. Bought a 1997 Z-29 Camaro with a add on cold air intake which when run at the strip produced no decrease in ET when put up against the standard air intake setup on the same car.
Now, take that same basic cold air package and modify it so that it pickes up cold outside air and air pressure and it will result in a performance gain.
 

STLtrailbSS

Member
Dec 4, 2011
1,617
If you pay me $100 I will add the same amount of HP a spacer does by topping off the washer fluid under the hood.
 

blazinlow89

Member
Jan 25, 2012
2,088
The throttle body spacer was originally designed to allow the air and fuel to get a more optimum mixture to provide better detonation, and power increase. The only reason these things work on a carb setup is because the spacer goes between the carb and the intake manifold. Since the fuel is mixed in prior to the spacer the helix effect could in turn give a bit more of a "mixing" effect to the fuel/air. However this should be negligible, as the air going into the manifold, then turning from the intake runners into the head and around the valves should already create a nice air/fuel mixture. This is not to be confused with a velocity stack, which has an arc and larger inlet than the carb, this gives a nice long curve which helps to accelerate air into the carb. The same thing works with a super charger, when I worked for my uncle we could see a 1-2 lbs boost increase with a velocity ring taking the veloute inlet from 4" to closer to 5.5-6".

With modern manifolds it is an entire different ball game. The things like the "tornado" only do one thing, and that is restrict flow through the intake tube. Getting into the new throttle body spacers all they do is provide a nice shiny piece of aluminum that are just that, bling that has no effect on engine power. The only thing they might do is increase plenum volume, which for most vehicles means absolutely nothing. Since the fuel is put into the mixture before the head, all mixing is done within that area. Mixing is not required as with a 4 stroke engine the actual air/fuel mixture will sit in the cylinder for an entire cycle before detonation at the end of the compression stroke.

ET time has very little to do with how something adds additional power, strange thing is you add more power to get a quicker time. The real goal is for efficiency, getting rid of baffling, an smoothing the intake path can help accelerate the velocity of the air entering the intake plenum, however it is only going to go as fast as it is drawn in. This is how alot of the big name intake manufacturers sell product, with a label that says 15hp increase it sounds all fine and dandy, until you look at a dyno graph. Alot of aftermarket intakes have a slight drop off on low end torque and power but have huge gains on the top end. Ideally you would want peak increase to be linear rather than just in a certain section, and a drop off on the low end. Most driving is down between 1500-3500 rpm. However the intake does make the engine sound alot more aggressive and cleans up the under hood look for a more custom appearance, all while giving slightly better efficiency.

In short throttle body spacer=expensive paper weight.
 

burnedfingers

Member
Mar 4, 2012
16
Quote:
In short throttle body spacer=expensive paper weight.

I believe I said about the same thing.

Quote:
ET time has very little to do with how something adds additional power, strange thing is you add more power to get a quicker time. The real goal is for efficiency, getting rid of baffling, an smoothing the intake path can help accelerate the velocity of the air entering the intake plenum, however it is only going to go as fast as it is drawn in. This is how alot of the big name intake manufacturers sell product, with a label that says 15hp increase it sounds all fine and dandy, until you look at a dyno graph. Alot of aftermarket intakes have a slight drop off on low end torque and power but have huge gains on the top end. Ideally you would want peak increase to be linear rather than just in a certain section, and a drop off on the low end. Most driving is down between 1500-3500 rpm. However the intake does make the engine sound alot more aggressive and cleans up the under hood look for a more custom appearance, all while giving slightly better efficiency.


ET means that you have added more power/more efficiency. There are tricks one can do to the aluminum intake manifold to increase efficiency/power and that would be to polish the internals and take out any air dams and such. There is a process in which an abrasive material is injected into a manifold manifold is off the vehicle by the way. The abrasive polishes the internals of the manifold. This is done with some aftermarket supercharged engines and the actual result is a decrease in the boost pressure which means the air is being able to be used more efficiently less in the way of the incoming air.

Actually a properly tuned manifold will yeald gains all thru the power band. A manifold designed to be efficient at 1500-3500 rpm will have the most torque in that range and less power in the top of the RPM band. An example was the third gen Camaro with tuned port fuel injection. It was designed to provide maximum torque and power up to 3500 rpm but fell on its face above that and there are dyno graphs to prove that. I also had one. The ONLY way to make this setup perform at a higher RPM was to change the runnner length and or change the manifold.

Now, if we want to talk variable valve timing we have the best of all worlds.

If you would like to talk aftermarket chips I could tell you that most result in a power loss instead of power gain. Dispite their adds that claim a 60hp gain I have not run across any yet that yeald a gain on a chassis dyno.
 

Irishboy02

Member
Apr 1, 2012
222
If you drive at WOT for a minimum of 2hrs on a highway, you MIGHT see a slight increase in gas mileage. Other than that youl just get a little extra WOOSH sound which will actually become annoying around 30-35mph. Concept worked, slightly, back in the day when dealing with the carb setups, now with EFI everything is computer controlled anyway so it wont change anything that the computer doesnt already know.
 

jimmyjam

Member
Nov 18, 2011
1,634
if you are running a carburetor i say go for it
 

burnedfingers

Member
Mar 4, 2012
16
Quote:
Installed this mod and gave me 30+hp and lowered my BP

all in all an A+

I guess there is a child in everyone:crazy:

Since I have been around for many years I have had experience using throttle spacers with carbs. These instances have been documented thru chassis dyno sessions. It is proven when set up correctly spacers do work with carbs. I don't recommend trying it with throttle body because there will be no gain.
 

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