by "CodyVella" (codyvella)
Published 02/01/2017 at 00:33
by "CodyVella" (codyvella)
Published 02/01/2017 at 00:33
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Now, I’ve done a lot of research on throttle body spacers lately. I just couldn’t wrap my head around how the whole idea of a spacer could add any performance gains to a vehicle. I dug around the net and found that the opinion on these things was split right down the middle. After a lot of research, I came to the conclusion that a throttle body spacer would be an improvement on a carb’d engine, as it would separate the hot manifold from the carb. But on a modern engine, would it really make any difference?
What’s everyone’s opinion on these things? Are they worth it, or are they just selling you Unicorn farts? Pictured is the spacer for my Xterra.
"DC3 LS, will be perpetually replacing cars until the end of time" (dc3ls-)
02/01/2017 at 00:43, STARS: 3
I’m in agreement with you. I think they work for carbs, not FI. However one thing I’m curious about is thermal intake manifold gaskets, that are suppose to keep the manifold cooler. Something like that could work.
"If only EssExTee could be so grossly incandescent" (essextee)
02/01/2017 at 00:43, STARS: 0
I have lichrully never heard of a throttle body spacer before now
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"garagemonkee" (monke)
02/01/2017 at 00:43, STARS: 0
Air transfers temps eventually, the temp of everything under the hood will all be the same temp, throttle body spacer or not.
"If only EssExTee could be so grossly incandescent" (essextee)
02/01/2017 at 00:45, STARS: 6
Yes, the venturi on a carb is exactly the same temp as the exhaust manifold /s
"Urambo Tauro" (urambotauro)
02/01/2017 at 00:50, STARS: 0
You’re on the right track when you mention carburetors. The way it was explained to me is that it’s all about the location of fuel delivery. If fuel is introduced into the intake stream before the spacer, then the extra thickness of the spacer gives a little extra room for the fuel and air to mix before reaching the cylinder.
So if your injectors are down by the valves, the spacer doesn’t do anything. But if you have a carburetor (or TBI) where the fuel enters the stream near the throttle plate(s), then there is a potential gain.
But performance isn’t the only reason to have a spacer. If, say, you changed the heads and now have tall valve covers that interfere with the throttle-body, a spacer might be needed for fitment.
"CodyVella" (codyvella)
02/01/2017 at 00:52, STARS: 1
This, I could 100% see making a difference. A thermal gasket would have the same principle effects on a fuel injected engine, that a spacer would have on a carb’d engine. On a fuel injected engine, the spacer would be much further upstream. I’m sure it would have some impact, but would it really be worth the $80-120 that spacers cost?
"Textured Soy Protein" (texturedsoyprotein)
02/01/2017 at 00:53, STARS: 0
Nope.
"Jake - Has Bad Luck So You Don't Have To" (murdersofa)
02/01/2017 at 00:53, STARS: 0
I thought the idea was to give more plenum volume downstream from the throttle plate. Not sure how this helps performance exactly but it does alter airflow in the intake manifold to a degree.
"Flynorcal: pilot, offshore sailor, car racer and panty thief" (flynorcal)
02/01/2017 at 00:59, STARS: 2
Sawzall and velocity stacks and you’ll never look back.
"Matt Brown" (superfastmatt)
02/01/2017 at 01:01, STARS: 0
You might get some tiny improvement in temperature, possibly offset by a tiny decrease in airflow fro extra wetted area drag. I imagine there is probably a better bang-for-the-buck modification out there.
"CodyVella" (codyvella)
02/01/2017 at 01:07, STARS: 0
Yeah but it’s supercharged. I can have a single velocity stack! Realistically it’d just be an air horn taped to the intake.
"DC3 LS, will be perpetually replacing cars until the end of time" (dc3ls-)
02/01/2017 at 01:29, STARS: 1
Just looked this up on YT. It appears to work. Although Idk how much hp it’d make. Probably quite a bit more than a CAI lol
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"Logansteno: Bought a VW?" (logansteno)
02/01/2017 at 08:22, STARS: 0
My dad has one on his ‘04 Silverado and it makes a giggle inducing whistling noise when you get on it because of it, other than that I have no idea if it actually does anything.
"Smallbear wants a modern Syclone, local Maple Leafs spammer" (smallbear94)
02/01/2017 at 08:31, STARS: 0
In general terms, you’ve pretty much hit it. On a carb they allow more travel between the fuel being added and being burned, therefore they can* improve the flow of fuel and mixing and plenum volume and a bunch of other things I don’t understand. With any kind of FI that isn’t TBI, the fuel is added at the cylinder anyways, so it’s doing nothing for you.
With that being said, the effectiveness of the spacer depends on what it’s attached to. Without the right carb, jets, intake/head machining etc, it may show itself to be totally useless. Kind of a “strong as the weakest link” situation. And with THAT being said, sometimes the engines themselves are just ornery and won’t make power whatever you do. Had a friend that built himself an engine, following an actual plan that was supposed to net 500lb-ft of torque. Never broke (afaicr) 485 on the dyno. We changed jetting (3-4 sizes), carbs (3!!), spacers (none, 1", 2"), ported heads and intake, valve rockers and springs... just didn’t want to make power.
Parting shot: A guy that builds engines for a living told me once, “Carbs are voodoo magic--you can try 10 of the same model and they’ll respond 11 different ways.” I think that pretty much sums it up.
"wiffleballtony" (wiffleballtony)
02/01/2017 at 09:07, STARS: 0
I assumed it was snake oil.
"Dave the car guy , still here" (a3dave)
02/01/2017 at 09:42, STARS: 0
They work... sometimes. Best on carbs but seldom on FI cars. Usually the best spacers are thermal ones on intake runners not the throttle body types. The theory is the vortex is changed and increases hp and torque, but its a theory that doesn’t always work.
Thermal intake spacers on Audi/VW 1.8t models have shown 3-7 hp increases depending on material and fit. If they disrupt flow between the manifold and head they can destroy any gains from a good port and polish. I’d expect if a throttle body spacer didn’t match the opening well it could do the same.
"TheD0k_2many toys 2little time" (thed0ck)
02/01/2017 at 11:29, STARS: 0
EFI not really worth anything unless you just like to throw stuff on your car. I think it got popular from old hotrod guys using them and then when EFI stuff got common people just used them and “thought” they improved performance
"StudyStudyStudy" (jesterjin)
02/01/2017 at 15:18, STARS: 1
I was just about to say, a throttle body spacer will eventually get heatsoaked as well, but the throttle body thermal insulators seem to be an interesting take.
I bought one for my car, but the 5 mm or so thickness was too much for my application. People seem to really like them though.
"WiscoProud" (wiscoproud)
02/01/2017 at 15:36, STARS: 0
The problem with the heat concept is two fold: The spacers are made of metal which conducts heat and heat rises. If the spacers were made of something non-conductive, maybe a case could be made, but most I’ve seen are aluminum, which is very conductive. Even if the spacer was non-conductive, heat rising off the engine is going to heat up the carb anyways. Maybe not as quickly, but the carb is going to be the temp of the engine bay.
I have read that big spacers (couple of inches) can be beneficial on carb’d engines as they give the fuel more time to disperse in the air charge. Not sure how accurate that is, but it makes sense. That being said, a half inch spacer is likely too little for any kind of improvement.
For fuel injected engines, they are especially useless as you can’t even make the heat argument. Since the fuel is either injected into the intake runners or the cylinder directly, its only air that’s rushing down the intake. A thin piece of metal is going to have no effect at all.
About the only good use I can think of is for fitting purposes. If you’re having issues getting aftermarket components to fit together, a spacer might give you some extra room to play with.
"WiscoProud" (wiscoproud)
02/01/2017 at 15:39, STARS: 0
I realize you’re being facetious, but the venturi would be the coldest part, due to the constant flow of air. The float bowls and everything else would heat up nicely though.
"If only EssExTee could be so grossly incandescent" (essextee)
02/01/2017 at 15:44, STARS: 0
My point being that the commenter said everything under the hood is the same temp.
"WiscoProud" (wiscoproud)
02/01/2017 at 16:07, STARS: 0
Sorry, instead of facetious I should have said pedantic.
"Echo51" (echo2047)
02/23/2017 at 06:08, STARS: 1
It does, the early zetec’s run a thick plastic middlepiece between the manifold and head, and the laters have an all-plastic intake to reduce thermal conductivity/emission