Home brew intake mods
 

So I have been reading for the least hour about cold air vs warm air and it just goes back and forth. So what's the conclusion? I was thinking about just smoothing out the intake lines with new tubing. Need some help hear. I know this beast has 55 BIG PONEYS but if I can gain HP or MPG without any loss either way I'm down with what ever.

-Matt

...COLD intake air helps HP at higher rpms.

...HOT intake air helps FE at lower rpms.

...remember the ICE is a adiabatic engine, ie: http://upload.wikimedia.org/math/6/e...2884024348.png

...hotter air in, yields better compression, in turn producing more power

...also, hotter intake air yields more consistant control of NOX.

Anecdotal info, for what it's worth:

My 01 s10 (4.3L) is equipped with a scangauge (that shows me IAT) and an aftermarket intake with heat shield & mylar/bubble insulation. I can tell no driveability difference whatsoever between heat shield & insulation on, 50 degree farenheit intake air, vs. filter mounted straight to the MAF which nets 150 degree farenheit IAT on the same day/same tank of fuel.

However, the less restrictive full intake DID make a huge difference in driveability vs. stock intake... not just on the butt dyno, the scangauge showed an immediate increase in fuel flow GPH at WOT compared to stock intake, which to me indicates more air's going in there too (fuel trim % did not change)

big engines do not care, (it starts with big air at 2 liters)...

little engines, the smoothing of channels, preventing surges (a calm cool source it can get on its own without changes) is a good way to go.

inlines have the intake danglng in the willywags, it makes it more sensitive, I learned this via my own boxer and inlines, I run both. the boxer needed a venturi, inlines don't care what the pipe is.

smooth for small is good.

As I understand it, Cold Air Indtake will allways be best for the effencicy of the engine. How ever - we most of the time drive on the first 0 - ½ inch of the accelerator, and only minute changes at the foot, can cuse one to use too much fuel.

By making a Hot Air Intake, you reduce the efrencicy of your engine, which means, that you now have to push the acc further down to achive the same speed.

The thorttleplate will thus be opend more.

Wheater or not this in itselves should lead to more mpg I really doubt, but having a wider range for your foot on the accelerator might be what generates the better mpg.?

But then again - I don't know much about HAI's and the theory behind it - but I understand the CAI in details.

I my car It's someehat diffucult to control the acc with the right accuracy, and just a slightly to hard a push on the acc, will cause FE to god down.

As for engines with Lean Burn technology - things about HAI might be different I suspect?

Don't konw anithing about those...

Shovel - seems like the stock airintake was very retictive on your car. New the engine can gett all the air it needs, thus improving on throttle responce and driveability...

A cold ir feed from the lower front of the car to near the airfilter / intake could further improve things.

I was thinking of changing the piping with smooth angles and droping the intake lower to get more cold air in.

-Matt

old tele man is right ,forget all you think you know about cold air intakes they are for hp and performance,warm air intakes increase fuel effecincy, and lower hp,there is alot of data to back these facts up, but dont try to tell someone from the performance arena that.

Two side of the same coin
 

Cold air gives you extra hp. It's up to you how to use them. FE or more speed.

You say it yourselves: "......and lower hp"

CAI might actually work better for him, with his big engine, than at HAI....

Can't really say what's best before it has been tried out on the specific wihicle.

Jyden-

I'd like to point out that what you just said makes absolutely no sense at all.

If you're making more HP, you're using MORE fuel to do it. There is never a point (OK, there is, but I doubt you're going to work it out) where you're making MORE HP with LESS fuel, meaning that a CAI which makes MORE power is going to get you the same distance with MORE fuel. Comprende?

If you can increase engine efficiency (there isn't much room for improvement here, really), at a given RPM, even if there is a net power increase, you will get better FE by doing it. That has nothing to do with burning more or less fuel per unit of power, though.

Adding a CAI to the engine means that two things happen -
1- The engine has to overcome more pumping losses, because colder air is more dense, thus doesn't flow as easily
2 - The engine has to induct air from a point further away than it would have been in most cases. This is not always the case, and it's a minute factor, but it does cause effects to power.

If you've got a dyno sheet that shows power or efficiency gains in a normal RPM range (sub 4500) with a CAI versus the OE intake, both at WOT and during normal acceleration (no more than 40% throttle), I'll delete this post.

I can say that because I already know you don't. They don't exist. I still have yet to see a CAI that makes any more than a few extra HP up at the very top of the RPM range, and that's attributable solely to the engine cooling action that the intake of colder air has.