has anyone tried making an intake heater?

[jrscteg]

Originally Posted by cbaber

Thats the idea for more power but we are after more MPG. Cold, dense are will make the ECU use more fuel, resulting in more power. In our world we want the opposite. Warmer air would require less fuel to burn, making less power but more MPG.

This is what I was thinking, I may try it but don't have a good way to a b a it yet.

[racerc2000]

instead of an electric heater why not do it like they did on the old cars? a tube coming from the exhaust manifold heat shield into the airbox. with an on/off controlled by vacuum

at the least it wouldnt cost more energy to heat the intake. it would just use the excess heat.

I do know my intake manifold has coolant running through it (people block it off for performance)

[jrscteg]

I was thinking for initial start up, until the car reached normal operating temp. Have it on a switch and use it the first 5 to 10 min of my commute. A tube off of the exhaust manifold isn't going to produce heat that fast.

[Frank Lee]

Alls Y'alls know this is a mini fuel burner right? It's not an electric heating element.

Wouldn't want to use it with a plastic intake manifold!

[oil pan 4]

Originally Posted by Frank Lee

Wouldn't want to use it with a plastic intake manifold!

I didn't thank of that, I dont have that problem (got a sheet metal intake and cast aluminum intake manifold).

If you are worried about the exhaust not warming up fast, cold start it one morning and see how long you can hold your finger on the exhaust manifold, or dump a little water on it and see how long it takes to go from dripping to completely dry.

[Ryland]

Originally Posted by jrscteg

I was thinking for initial start up, until the car reached normal operating temp. Have it on a switch and use it the first 5 to 10 min of my commute. A tube off of the exhaust manifold isn't going to produce heat that fast.

Really? because my first two cars had exhaust heat for preheating the air and it was warming up the intake air in less then a minute of the engine running, the exhaust is the first thing to get hot, even the Honda N600 that we have uses the exhaust for cabin heat and you get heat by the time you get out of the drive way!

[cbaber]

Originally Posted by kach22i

Maybe I'm faulty in my logic, but if you make more power, aren't we talking about efficiency?

A more efficient engine gets better MPG, right?

I know that there are always exceptions to the rule, just talking comparables here.

From what I have read the denser air will make more power because your ECU senses the better air and adds more fuel. Yes it is more efficient because you are making more power with the same displacement. But it won't really increase MPG because your ECU compensates the dense air with more fuel. If you could tell your ECU to allow the engine to run lean (not adding more fuel to the mixture) then your MPG would go up. This is why the lean burn engine in a civic HX gets better MPG than a standard civic.

At least thats what I understand. If you google this question you see many opinions but you cannot trust all of them.

[racerc2000]

many things come into play with making an efficient car.

for instance. compare my 2010 honda element SC 2.4L 166hp
to someone I know with a 2003 honda element 2.4L turbo 463 WHP

when driven in a normal manner why do I avg 17.5mpg but he avgs 26mpg

epa is 20/24

even if my best was 24.4 still it goes against the logic.

so I guess it all comes down to doing it right. not just half way.

[unorthatrox]

hi Im new here, searching this subject brought me to the forum so Im starting here. First off, I have an RX8, incredible little potent engine with a very modern emissions setup. But for those that never knew... city driving yields about 12-14 mpg out of that 1.3L engine. I have over 80k miles, and it runs very clean. It's internal seals are also incredible. Ive pulled vacuum lines to find it still holding high vacuum over an hour after shutting down.

On to the subject. Heating an intake charge is not what we look for to increase performance and thats proven on the drag strip by boosted cars using ice water in air/water intercoolers. Also proven by dyno testing when heat soak consistently lowers horsepower. Now the RX8 uses coolant to heat the throttle body. I suspect this is one of the late additions that lowered its horsepower rating upon release. Attempts have been made to bypass the throttle body in order increase power. Ive never seen dyno results of this but I think it would give a very small gain but show resistance to power fade due to heat soak in repeated testing. The side effect of the bypass is that MPG suffered greatly (some reported 1/3 total mpg losses). Here's my reference for that, note user comments at the bottom. Never mind I need 5 posts to post a link here.

now racerc2000 brings up a good point about turbo cars. Ive personally seen several turbocharged cars pulling mid 30s for mileage and several of these are 80's cars that bleed oil like its cool. There are 2 reasons a turbo car gets awesome mpg, first the turbocharger heats the intake charge a LOT. Intercoolers are widely utilized to cool this down to increase power and reduce detonation risk. Also note that a critical element to creating boost is load and the heat generated on the turbine side of the turbo increases load. Methods are employed here to coat and wrap the metal so that the heat gets to the impeller and is not soaked into the metal and lost into the engine bay.

These 2 together are about all the proof I need that a heated air charge does indeed raise your mpg. Yes this comes at the risk over power output but probably not greatly so and ultimately im talking highway driving very city/spirited driving for when you want this heat.

[unorthatrox]

I wanna get a few things outta the way as well for future conversation. This is the only (green) forum I have ever joined due to my view conflicting with the politics and many of the users that push such "green"ness. I wish to not discuss the politics and simply put out that I am strictly against any method of energy "saving" that uses one form of power output to convert something else into power for and engine. Gasoline is proven to be the most potent way to produce energy that can be harnessed by a street driven vehicle. There are some small exceptions like acetylene dual fuels for example that are better but simply impossible or impractical. If this werent the case I'd be lobbying for nuclear powered cars. My existence here is to aid in the discussion of ways to convert lost energy into used energy.