Do throttle body spacers really work?

This thread is LOL.. someone post actual number and not "I think I got more power" please. I would like to see what a documented upgrade can do, and please, not one from a manufacturer, they are very biased.


I have a spacer and I could not tell the different after. I've been running it for near 10 years and if I took it off tomorrow, I would be hard pressed to see any changes.


Quoted my self since I like the sound of me typing, and I am still waiting for the proof, not opinion.
 

Throttle body spacers work great if they are installed right :purple:
 

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This is what happened to my TJ 02 after the spacer install... i already had magnaflow exhaust and added a K&N air intake and a 1" spacer and when i really noticed the difference was when i put it in 4 wheel low. there was so much more torque.. really made a difference in low gear.. so i think thats the easiest way to tell the difference.
 

i installed a spacer along with a header, a glasspack cherrybomb,62mm throttle body, k&n filter and home brewed snorkel that sits in front of p side wiper.I did all of these mods in one shot,amazing difference in power,dont pay much attention to mileage.I read in jp magazine that they saw less than 1 horsepower difference with spacer.I have removed the spacer with no difference in performance.My thoughts are it is a placebo.If i had to do over would prob start with a header and exhaust work,then cold air intakeand free flow filter and then see if a 62mm throttle body is needed.It is pretty hard to increase power and mileage because we get more power so we use it throwing fuel economy out the window.
 
Quoted my self since I like the sound of me typing, and I am still waiting for the proof, not opinion.

This is a quote taken from here which in turn is a quote from ANOTHER site I cannot find:

GearPoet said:
Yesterday a 4.0L TB from a '98 Cherokee arrived by UPS -- to be installed on a 2000 2.5L TJ. With the help of a neighbor who teaches auto mechanics at the local high school (absolutely cool woman who decided to make it a day project for some of her students), I dyno-ed everything in stages. Checked the air flow, too.

Results, with stock (2.5L TB & no spacer)as baseline:

(1) Poweraid spacer only -- +2 HP, 8% less airflow (Evidently, the helix bore, lips of which extends beyond intake & TB opening, actually cuts down on airflow. But the spacer does "cool" and extend air volume, hence horsepower increase.)

(2) 4.0L TB only -- + 6 HP, 16% more airflow (no surprise here)

(3) 4.0L TB & grind out intake opening to match lower TB opening -- + 13 HP, 29% more airflow (Wow! Grinding out the intake opening did make a difference!)

(4) 4.0L TB & Poweraid helix spacer & grinded-out intake opening -- +16 HP, 2% less airflow from #3 above(overlapping helix bore is still cutting off airflow, but spacer is still cooling & increasing air volume)

(5) 4.0L TB & grind out helix bore in Poweraid spacer to match lower TB opening & grinded-out intake opening (the Big Kahuna) -- + 24 HP, 39% more airflow (Wow again; the optimal configuration, obviously)

It should be noted that grinding out the helix in the Poweraid spacer still leaves a partial helix in the walls -- the main difference being that the helix now has rounded edges rather than sharp ones. My auto mechanics-teacher neighbor suggests that these rounded edges are actually more aerodynamic than the original sharp ones, and will still "spin air" -- so perhaps the "pulse-organizing" effect I mentioned in an earlier post will be retained, if in fact there is such an effect.

So, to reiterate, I ground out on the helix bore of the Poweraid spacer, and ground out the intake opening, both to match the lower opening of the 4.0L TB I swapped in. Dyno-ed & tested airflow, results: +24 HP, 39% more airflow.

Seat-of-the-pants impression: idles smoothly, more torque on the low end, smoother accleration through the midrange, and better performance above 2700 RPM. No hesitation, no engine codes.

One MAJOR suggestion: if you grind out your intake opening, be VERY CAREFUL about aluminum filings in the intake manifold. We stuffed everything with tack cloth -- sticky cloths which can be purchased at a hardware store -- rather than shop towels. The tack cloth caught about 95% of the filings, but there was still a small mess in the intake. We vacuumed a lot of the leftover out with a shopvac, but we still had to use tack cloth attached to a long, thin screwdriver to "mop out" the runners. On the TJ there are also four open plugs/hoses attaching to the intake below the TB -- you'll have to clean those, too. It took longer to clean out the intake than it did to bore out the opening, but it can and needs to be done.

Finally, should say that the TJ has a two-stage K&N filter system, an MSD ignition system & coil, high-gapped Champion truck plugs, a Flowmaster delta-40 catback, and a case-full of Mobil 1 synthetic oil. All or part of which may have a synergistic effect on my results, since mods usually affect each other.

Cheers, GP http://www.forumco.com/jeffy/topic.asp?TOPIC_ID=858&FORUM_ID=6&CAT_ID=1

More Info: (1) The intake is soft aluminum, so we used a medium tungsten rasp, followed by a fine fluted grinder bit, followed by a fine polisher. I'll admit it's not even -- hard to get consistency around the runner walls which are nearly flush to the intake opening. The spacer is a harder grade of metal, and trickier, even when clamped in a vise. Doesn't look pretty anymore, at least on the inside.

(2) Tested at 1800 RPM and 2800 RPM with an average between the two -- but the results were fairly similar.

(3) We figured the following: At 2800 RPM, torque was up by about 16% with #5 option above. At 1800 RPM, torque was up by about 14%.

Again, folks, consider the mods and the synergistic effects -- your numbers may be different depending on what you have your rig, mileage, mechanical conditions, altitude, etc. I give this just as a general indication.

Ambient air temperature: 74 degrees Humidity: about 35%

From what I have heard, the TBS also moves the torque curve down a bit to the lower RPM range, which is good for Jeeps. Also, airflow increases, which means you can get more air (read, more O2 for combustion) in the same period of time, and the air should be a bit cooler (in theory, anyway), which also increases air density (again, more O2). Now, to get all the benefits, you need to increase the diameter of the intake manifold, and you need to make other mods (high flow filter, injectors and ignition mainly, but a more aggressive cam will also help) to take maximum advantage of this.
 

Notice those that think the TB spacers work on TJ's also put on a different air filtration system.

Think about it!
The intent of the spacer is to swirl the fuel and air mixture to atomize it better. On carburetors and on Throttle body injected vehicles where fuel is injected in the Throttle Body - fuel is up there where it can mix. They can and do work on those applications.

But TJ's and the like don't have fuel up there - it's injected in the head right by the intake valve.
Try it -- Look where your injectors are.
Swirling air somewhere else doesn't help any. By the time the air makes the turn under the spacer, then slides down the long manifold and makes another turn to the head, all that swirling has stopped.

If anything, the swirling of the air - turbulence - just below the TB plates could cause a bit of restriction. Notice how performance building also includes smoothing and polishing the intake runners to eliminate turbulence.
The swirling is counter productive.

But - those that claim improvements - 3 types of people.
1. -- Those that only added the spacer and are subject to the placebo effect. (I want it to work, therefor it does.)

2. -- Those that also added a "cold air" intake - it's not the cold air that helps, it's getting rid of the very restrictive stock air box trying to get all it's air through the tiny hole in the front of the box. (Try jogging while trying to breathe though that little airhorn.) That's a bunch of restriction eliminated.
Cold - When moving the air in the engine compartment is not much hotter than outside air - but it seems like it when you stop and open the hood.)
If it was a race car trying to get every tiny bit out it can make a slight difference. But thise is a JEEP!

Try it
, use a remote thermometer.

A 4.0 liter engine needs to be able to breathe in 2 liters of air every revolution. At 2000 RPM that's 4000 liters every minute - picture 4000 liters of coke!

Try it - simply disconnect the tube into the stock airbox and go for a ride. You'll see.

Eliminating the restriction lets it get more air - but that would make it lean. The ECM's adaptive memory soon compensates (and remembers) for the extra air with more fuel. So no gain in mileage there. The ECM still maintains the right A/F ratio. (Unlike caruretted systems that need to be re-jetted.)

But - to get the same amount of power from the engine the throttle doesn't need to be open as far. And when you try to accelerate it still takes less throttle opening. At WOT Wide Open Throttle is gets more air and fuel giving a tad more power.

Try it - try to jog with a gag over your mouth.

TB spacers - not a help.
Reducing the restriction from the stock box - priceless.

3. -- And the 3rd type of person - with something to sell you!

And the 4th entity - magazines that have articles touting what their advertisers sell.


The 1" addition - the height adding power scam - if it was going to take advantage of the RAM effect in the intake, that spacer should be more like 2-3 feet long. About the same distance as a header runner before the collector.

I'd like to see a magazine do a shootout between the spacers and big STP stickers on the doors.
 
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Notice those that think the TB spacers work on TJ's also put on a different air filtration system.

Think about it!
The intent of the spacer is to swirl the fuel and air mixture to atomize it better. On carburetors and on Throttle body injected vehicles where fuel is injected in the Throttle Body - fuel is up there where it can mix. They can and do work on those applications.

But TJ's and the like don't have fuel up there - it's injected in the head right by the intake valve.
Try it -- Look where your injectors are.
Swirling air somewhere else doesn't help any. By the time the air makes the turn under the spacer, then slides down the long manifold and makes another turn to the head, all that swirling has stopped.

If anything, the swirling of the air - turbulence - just below the TB plates could cause a bit of restriction. Notice how performance building also includes smoothing and polishing the intake runners to eliminate turbulence.
The swirling is counter productive.

But - those that claim improvements - 3 types of people.
1. -- Those that only added the spacer and are subject to the placebo effect. (I want it to work, therefor it does.)

2. -- Those that also added a "cold air" intake - it's not the cold air that helps, it's getting rid of the very restrictive stock air box trying to get all it's air through the tiny hole in the front of the box. (Try jogging while trying to breathe though that little airhorn.) That's a bunch of restriction eliminated.
Cold - When moving the air in the engine compartment is not much hotter than outside air - but it seems like it when you stop and open the hood.)
If it was a race car trying to get every tiny bit out it can make a slight difference. But thise is a JEEP!

Try it, use a remote thermometer.

A 4.0 liter engine needs to be able to breathe in 2 liters of air every revolution. At 2000 RPM that's 4000 liters every minute - picture 4000 liters of coke!

Try it - simply disconnect the tube into the stock airbox and go for a ride. You'll see.

Eliminating the restriction lets it get more air - but that would make it lean. The ECM's adaptive memory soon compensates (and remembers) for the extra air with more fuel. So no gain in mileage there. The ECM still maintains the right A/F ratio. (Unlike caruretted systems that need to be re-jetted.)

But - to get the same amount of power from the engine the throttle doesn't need to be open as far. And when you try to accelerate it still takes less throttle opening. At WOT Wide Open Throttle is gets more air and fuel giving a tad more power.

Try it - try to jog with a gag over your mouth.

TB spacers - not a help.
Reducing the restriction from the stock box - priceless.

3. -- And the 3rd type of person - with something to sell you!

And the 4th entity - magazines that have articles touting what their advertisers sell.


The 1" addition - the height adding power scam - if it was going to take advantage of the RAM effect in the intake, that spacer should be more like 2-3 feet long. About the same distance as a header runner before the collector.

I'd like to see a magazine do a shootout between the spacers and big STP stickers on the doors.

I actually disagree; while I do agree that the Helix does nothing for you (the "tornado" effect), the spacer DOES help. If you look at my post above, it's hard to argue the dyno numbers. Basically, a TPS will move the torque curve slightly, which CAN be beneficial depending on where you want your curve...
 
Then maybe you can explain how they can mix the air and fuel when there isn't any fuel? Magic?

Placebo effect.

No, they are not mixing fuel; they create a larger volume of air PRIOR to the TB which can be readily ingested by the engine without having to pull it through the filter... or the non-smooth hose connecting the filter to the TB. This also means that you get a quicker throttle response.

And, by the way, the dyno does not measure magic; just reads out real data as measured by a computer. How can you argue dyno numbers (posted above)? Is the dyno affected by the placebo effect as well?

In my case, I studied my mods to complement one another. For better atomization of the fuel, I did 2 things; one was increase fuel pressure to 46PSI (keep in mind I also have a performance cam installed, which is why I went to 46 instead of 40PSI) and used 19# injectors (the one with 4 nozzles instead of 1 from the stock injectors; the 19# injectors are actually measured a t a different pressure than the Jeep runs stock, so you need to increase a bit the pressure to get the same flow, and in my case, I went with increased flow to compensate for other mods).

For improved air to the engine, I used a 4.0L TB bored out to 62mm and the 62mm TB spacer. I also use a high flow filter (I have found that the Fram Airhog to be a better choice than the K&N), and I use a snorkel (which acts as a CAI, as the air is not coming from under the hood but rather way up and from outside; to a certain extent, the snorkel also works a bit as a ram air).

I also improved ignition with a Performance Distributors system, which allows you to gap up to .060" isntead of the stock .035".

So now you have more air, more fuel, and a stronger ignition to light it up. All you need to take care of is the exhaust, which I did by means of a high flow cat from Magnaflow and a cat back from Borla.

I also freed up a few ponies by using a FoMoCo eFan, and helped the engine by regearing to 4.88 (to compensate for my 33" tires). My 2.5L drives just fine in my opinion (I drive it at least twice a year from Panama to Costa Rica, a 600 mile roadtrip, and wheel it as much as I can).
 

""""""No, they are not mixing fuel; they create a larger volume of air PRIOR to the TB which can be readily ingested by the engine without having to pull it through the filter''''''""

+++ Prior to the Throttle body? - you mounted it ABOVE the TB"? Or you mean AFTER the TB.
The slight extra volume of 62mm x 1" adds an insignificant amount of air compared to the air ingested at even 2000 RPM. 2.5 Liter * 2000/2 = 2500 Liters/minute. Talk about placebo! +++


""""""And, by the way, the dyno does not measure magic; just reads out real data as measured by a computer. How can you argue dyno numbers (posted above)? Is the dyno affected by the placebo effect as well?""""""

+++ As a former owner of dynos in performance shops, they can be distorted to read what you want. It's impossible to duplicate runs when you have to take time between runs to change parts like that. Temperatures change in everything, from the PA unit, engine, oil, water, trans, diffs. +++
+++ And YOU did the tests yourself, or a magazine selling something?+++

""""""In my case, I studied my mods to complement one another""""""

+++ obviously read the advertisements. +++


""""""increase fuel pressure to 46PSI""---"" and used 19# injectors"" - """I went with increased flow to compensate for other mods).""""""

+++ Ford injectors can have an increased flow, but that extra flow is only utilized at Full Throttle - IF even then. The ECM simply closes them quicker. The amount of fuel delivered is governed by the open or "on" time of the injector, NOT the ability to flow fully open - which never happens.+++

""""""For improved air to the engine, I used a 4.0L TB bored out to 62mm""""""
+++ I won't argue that - a good mod - useful at or near WOT. At lower speeds not utilized.+++


""""""I also use a high flow filter (I have found that the Fram Airhog to be a better choice than the K&N), and I use a snorkel (which acts as a CAI, as the air is not coming from under the hood but rather way up and from outside; to a certain extent, the snorkel also works a bit as a ram air).""""""

+++ Advertising again - you must have the filter mounted in the snorkel - isn't the tube to the snorkel long? Restriction in itself.
Ram air - maybe slightly at speeds above 100 MPH - helps overcome the added tube restriction.+++

"""""I also improved ignition with a Performance Distributors system, which allows you to gap up to .060" isntead of the stock .035".""""""

+++ They are usually known by the name DUI here - a "prettied up" up HEI. The polished chrome does what? Same guts.
Try gapping the plugs at .045 - idle will be better and WOT won't have the misfire you now have. Use the plugs the heads were designed to use, not "trick Performance" bling.+++

Enjoy -
 
Prior to the Throttle body? - you mounted it ABOVE the TB"? Or you mean AFTER the TB.
The slight extra volume of 62mm x 1" adds an insignificant amount of air compared to the air ingested at even 2000 RPM. 2.5 Liter * 2000/2 = 2500 Liters/minute. Talk about placebo!

You are right; I meant prior to the intake, not TB. And the effect is not constant, but rather RESPONSIVE (ie. read the complete sentence); how much air is available for immediate consumption to MAKE the engine rev up.

+++ As a former owner of dynos in performance shops, they can be distorted to read what you want. It's impossible to duplicate runs when you have to take time between runs to change parts like that. Temperatures change in everything, from the PA unit, engine, oil, water, trans, diffs. +++
+++ And YOU did the tests yourself, or a magazine selling something?

Posted by a fellow forum member not selling anything; all the data is recorded, and there are no changes in temps or settings. But I wont argue the fact that dynos can be made to read in the general direction you want it to show... However, they still remain the best way to measure differences.

Ford injectors can have an increased flow, but that extra flow is only utilized at Full Throttle - IF even then. The ECM simply closes them quicker. The amount of fuel delivered is governed by the open or "on" time of the injector, NOT the ability to flow fully open - which never happens.

I disagree; more pressure and shorter times, plus the 4 nozzles instead of one gets better atomization of the fuel. Also, with an aggressive cam, and increase flow of air into the engine, you can burn more fuel to get more power. Power is a question of how much fuel you can burn in a certain period of time. The ECU WILL compensate the flow of the injectors (except at WOT and at warm up), but not for a certain volume. It compensates, rather, to reach a certain mix of fuel/air. Put more air in and you can burn more fuel and this results in more power... Basic principle used by turbos and superchargers.

you must have the filter mounted in the snorkel - isn't the tube to the snorkel long? Restriction in itself.
Ram air - maybe slightly at speeds above 100 MPH - helps overcome the added tube restriction.

I said SORT OF works as a ram air (ie. READ before answering!), and pressure increases faster than you mentioned. It's exponential, as air density is constant, but speed is not.

Anyway, the reason for the snorkel in my case has nothing to do with CAI or ram air, but with river fording... Nothing kills an engine faster than a mouthfull (or pistonfull) of water... But it DOES help the engine ingest colder air, as the air source is NOT inside the hot engine bay.

They are usually known by the name DUI here - a "prettied up" up HEI. The polished chrome does what? Same guts.
Try gapping the plugs at .045 - idle will be better and WOT won't have the misfire you now have. Use the plugs the heads were designed to use, not "trick Performance" bling.+++

Enjoy -

So now I am NOT using the sparkplugs the head was designed for? It's the same plugs, just gapped differently... Oh, and now I have got misfires, as well? Funny, I did not notice them until I read your post...

My point is not to argue (although it seems to be your!), but rather to point out that one mod needs to complement another. A single one will not cause that much difference unless you make other changes to take advantage of that mod. Oh, and most of the mods on my Jeep are not from commercial houses; the adjustable FPR, bored TB, TB spacer, hand throttle, etc. are not from commercial house but rather home made, so there is no advertising to buy...

And last, but not least, have you tested these mods to be able to toss them aside as pure hype? I have... And while not all the mods have made significant changes, all of them together make the Jeep work better than it used to (but I will concede that this is seat of the pants testing, so some placebo effect may influence my perception).

Regardless of what you think/know that works or not, the important fact is that the Jeep does what I want it to do rather well, which is a good balance between street and trails (mud mostly). So you mod your Jeep as you see fit, and I will do with mine as I see fit.

Anyway, I dont share your opinions, but I respect that you have a different view from mine, so I will not get into an argument from here on.
 

It's your rig, believe what you want.

But you've missed a mod that's as important, if not more important than most of your mods.

BIG STP stickers on the doors.

BTW - if you are using the stock plugs and bending them out to .060 it's too far - the spark won't jump to the ground electrode's tip, it'll hit somewhere on the side. Reduce the gap a little - you'll probably feel a difference.

:p
 
Throttle body spacers offer no real improvment on anything a wet intake ie carb to tb injection where increasesd plenum length is benificial. Multi port motors are just air going through the throttle body and have plenty of runner volume to supply the engine. Tge biggest way to boost power is cold air kit and an exhaust.
 

I strongly beleive TB spacers do work, the old style with the screw design only works at slow speeds and is good for torque only. Smooth bore is better flow smooth air transitions and increase performance all around. If you are interested we carry some that will outperform the competition. If you like look under the vendors forum, it will explain how this new design works. Its under GSP Power Spacers. Let me say they work extremly well under all RPMs with smooth air transitions. I am not trying to sell you one or push one on you, just saying they work along with cold air intakes and bigger throttle bodys. All I am saying it will explain how they work.
 
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