It's not like you're gonna see like a huge gain or anything. More like low percentages relative to your engine. Kinda how K&N claim like a 2% increase. On a 100hp engine that's 2hp.

More air gives (which a CIA does) the fuel more air to atomize into. More surface area for the fuel to burn causing a more efficient and hotter burn which in turn equals more power.

Again these gains are small but every bit helps. Intake/exhaust, heads, ignition, plugs and wires and a tune could all add up. Each one helps the other but it also costs money to do all these sometimes being not worth it for a daily driver. Driving habits also help a lot too. Increased my average milage on my old 4 banger Ranger from about 380 miles a tank to over 450 with just doing the speed limit everywhere and not gunning it from stops.

I'm be no means an expert on this and could also be wrong on my thinking.

 

If the idea of the tb spacer is to twist the air in theory, I would think that once the twisted air smacks the back of the intake manifold or changes direction, the vortex is lost. Has anyone heard of putting the same idea between the head and intake. There, the vortex would be created at the cylinder.

 

I always thought the phenolic spacers acted as a thermal block to sort of insulate the intake from the direct heat of the motor.

At least back in the days of carbs, a phenolic plate was used for that purpose between the carb and intake if memory serves me correctly.

 

That might be true as well. I know that Mustang guys also use the spacers to raise the intake a bit to clear tall valve covers. Stock and stock style aftermarket 302/351 uppers hang over the head on the driver's side.

 

Sorry I am so negative with my posts lately on here guys and I don't mean to take this off topic but I have to disagree with the above statements.

Like any business car companies are doing what they do to make money and that is all.They don't care about the environment and they don't care about what you spend on fuel.They care about satisfying the required government regulations,selling cars and making money.
They have the means to produce way more efficient cars and trucks but fear we will not be willing to make the sacrifice of riding around in go carts which means they would have to take a huge risk rolling a new product line out that is not consistent with the norm.
If they did care then they would just shove the efficient eco friendly cars down our throats regardless of profits but really who the heck would do such a thing as business men and woman? I wouldn't, I would go where the sure money is.
Lets not forget the oil companies which drive the global economies.If they make no money then economies crash plain and simple.
I could go on and defend my stance further but as I said I dont want to take the topic off track.

Everything else looks like good information in this topic.I was thinking of getting a spacer for my jeep but probable will not bother now .

 

If you have more air coming in that's where a tuner/chip would come into play imo. If you have more air but tune the ecu to compensate and advance/retard the timing then you have a touch more power and better atomization/fuel efficiency.

Food for thought. My dad's ranger has a gutless 3.0 v6 in it. My buddy is a sct dealer and we spent an hour tuning the ranger. Air/fuel ratios, wot timing, shift points, shift firmness, converter lockup points, etc. All this truck has is a k&n drop in filter. Stock as the day it rolled off the assembly line.
0-60 times jumped. 1/4 mile times, cut 1.5 seconds off in the 1/4. Much more power, tranny shifts way better converter locks up better holds gears longer. All this makes the truck drive so much better as it drags around its heavy 4x4 ext cab self around.
So... does the fuel ecconomy suffer from better power? No absolutely not. It gained probably 2 MPG from the tuning. Impossible you say but its true. I just wish Chrysler products had stand alone tuning like GM and Ford. My $.02 for what its worth.

 

I agree with FordFoxGT, good wires, good plugs, good distributor first and then high flow exhaust manifold and a brand new trottle body or remove and clean the current one you have. remove the loose in the trottle cable while cleaning or replacing the trottle body. Replace the air filter with a k&n.