HOT AIR SUCKED BY OPEN TYPE AIR FILTER

[wannaberacer]

hmmm..interesting ang topic

i just wanna ask kung how much mag palagay ng fabricated heat shield and kung kailangan pa ng ducting hose para lumamig lalo....

i've been using a short RAM intake for my ride and ive been sucking hot air for a couple of months now  

thanks

[Jango]

hmm before reading this thread, i had no idea that bolt ons required this much study...

now im leaning towards putting my stock airbox once again...

[Accord GTR]

hmm before reading this thread, i had no idea that bolt ons required this much study...

now im leaning towards putting my stock airbox once again...

I don't mean to make a big deal out of bolt-on mods.  It may not be as bad as I make it sound to be.  But this is what I've learned lang from my experience with different set-ups and learning about engine management systems.  Cars nowadays are so well-tuned and sophisticated that kaunti lang change and you really get to notice the difference.  Like when I first got my Type R and brought it to the dyno to baseline it.  It was using the stock ECU with a bolt-on short intake system.  It put out 150whp but the mid- and top-range was dangerously lean.  I got an AEM EMS and had to learn how it worked so that's how I found out about how all these sensors work.  We tuned it again and added about 10whp to the peak and 20whp to the mid-range but the important thing is we "cured" the lean condition.

Running lean kasi can do a number of things to your engine.  1st, it creates higher than normal combustion chamber temperatures.  Since your valve seats have the least amount of material, this will be especially vulnerable and after a while, may crack, resulting in leaks and loss of compression.  2ndly, sustained high temps will heat up the sharp edges in you combustion chamber such as piston domes, spark plug ends and sharp edges in your chamber tops and make them glow red hot.  This will lead to pre-ignition where the air-fuel mixture ignites before your spark plug fires.  This usually happens as your piston is still well into its upstroke.  When that happens, something has to give, either the connecting rods, piston rings, pistons or valves resulting in a blown engine.

[Jango]

ok now i might really swtich back to stock...

[7gk20a]

JaNgo - I don't think putting CAI alone will make your car run lean like that...I am sure the current ECU has enough to compensate for the change.

[Jango]

hmm SRI eh... the  tube gets REALLY HOT. Hot enough to melt some rubber tube that was put on tope of it

[R-A-Y]

hmm SRI eh... the  tube gets REALLY HOT. Hot enough to melt some rubber tube that was put on tope of it

Is it those metal/aluminum tubes? Yes they can get quite hot if they are

[borly]

maybe heat shield na talaga ang kailangan...

[mykboo]

ok now i might really swtich back to stock...

question po... i know that the stock ecu can compensate for the greater air after installing an intake pero wat if the car doesnt have an ecu?? i installed an intake in my truck (L200) using a simota filter and an aluminum tube.. its just an SRI pero could this in anyway lean my mixture?? or it doesnt matter in diesel engines?

[the driver]

I'll try to answer both your questions, Mark & wcv:

Not so familiar with your engine Mark but I'm assuming its fuel injected or EFI?   It its carbureted, then I'm just wasting my time!  ;-)

All EFI engines have a factory-programmed ECU that contains the fuel & ignition maps that determine how much fuel and ignition timing the engine gets for a certain set of engine parameters:  throttle position (how much you step on the gas), rpm, engine load, coolant temp, air inlet temp, etc.  The result is to give your engine a power curve (HP & torque) that more for economy and daily driving.   These maps are programmed at the factory for the climate and conditions where the car will be marketed at.   Naturally, if you get a JDM (japanese) engine, it won't be optimized for our climate and conditions.   But since you have a PHIL model, lets assume it was tuned perfectly for the Phils.

So what happened after you modified your engine...you gave it more air and you reduced the backpressure in the exhaust.   But the ECU doesn't really know that and its still using the same maps as a stock engine.   So you kinda ruined the mix.   It's like, you wanted your wife to bake you your favorite dish that your Momma used to make you when you were a kid so you asked Mom give her the recipe.   But your wife thinking she's a better cook than your Mom, put more sugar and spices without changing anything else.   So, anyway, finish the story...the recipe is like the fuel & ignition maps.  The sugar and spices are like the modifications you made.   Is the end result what you really wanted?

This is what I think is happening:  The I/H/E basically did give you some added torque in the lower range and a bit more hp in the upper rpm's simply because of better flow.   But your engine is now running leaner, meaning the air-to-fuel ratio or AFR is now less than what the factory wanted it to be.   Lean engines get more economy but also run hotter because they are more prone to higher combustion chamber temperatures with less fuel to burn.   What do you do when you want to make your BBQ hotter?   You fan the flames, right?   That's what you did with your intake/filter when you didn't bother giving it more fuel.   Added fuel, if you can burn it, makes more power and also serves to bring down combustion chamber temperatures.   But added fuel hurts economy and causes more harmful emmisions so Toyota tunes to get that optimum "balance".   Screw with it at your own risk!

So your engine runs ok for a while but after awhile, your combustion chamber temp is rising.   Do you sometimes hear a metallic rattling sound when you accelerate from idle or climbing uphill from low rpms or carrying a heavy load?   That's the sound of death for your engine or "knock" or pinging!   Sucking hot air during heavy traffic just makes things worse but the problem is more the AFR than the hot engine air.  Eventhough you add a cold-air intake, the problem would still be there or get worse. 

Here's more bad news facts that you'd like to know.  Most modern engines are tuned to what's called a "lean-burn" technology for better economy (only racer's like power over economy anyway).   By putting in your I/H/E, you made your engine burn even leaner.  So, bad, very bad.

How to solve it without going back to stock?   Hehe.   Add a piggyback engine management system from the folks at Fusion R that will re-tune your ECU and have Autoplus dyno your engine to tune it.   Minimum cost?  P35,000.   But for what?  You don't race.  You just wanted more power.   But like the recipe of your Mom, you need to change everything else to get back the "balance" if you want a safely running, efficient and powerful engine.

Sorry  ;-)

   Air Fuel Ratio means the computer will read the amount of air intake and have the right amount of gas based on that ratio. Meaning it will compensate and adjust automatically as an ECU designed for. So even if you modified it will run with the right AFR. IN MY OPINION AND UNDERSTANDING NO PROBLEM WITH BASIC MODIFICATION.

[Dom]

Ganda ng post na ito. Very informative.

Please correct me here if I'm wrong. But from how I heard before that when replacing the stock air box to an aftermarket part, the positioning of the air sensor (i forgot what its called) is important to retain the engine's efficiency. Where there could be gain or loss when there is significant change in it. So changing to drop in will be good for the engine.
Pansin ko lang na ang ginawa ng Spoon is like drop in. Mugen is different because they used the same tube and changed only the airbox. (not sure where the sensors for the mugen if changed). Just my ten cent thought.

Tama ba ito?

[2slow240]

i think it depends on the sensor that the car is using.

if its using MAP sensor it just reads pressure in the intake manifold to calculate how much air and fuel its going to put in.

on MAF equipped vehicles, it measures the actual amount of air going inside the throttle body.


the MAF compensates for changes in the intake and the exhaust system better(aftermarket intake or exhaust), while with the MAP you have to re-tune, to properly use your upgrade.

cheerio

kung mali correct na lang hehe