Nick86

iTrader: (1)

I'd still like to see some pics of your setup - first of all for general interest, and secondly I am somewhat hesitant to believe that it is the increase in HP that's causing this feeling of lag.

Have you inspected for vacuum leaks after the install?

iceblue

Sigh.. Some people so closed minded to facts other then they see fit.

There is a volume carectoristic of pipe. You could never get more air in your car befor then your smallest portion of your air box this being smaller then the inlet and outlet of your AFM thus resulting in a lower HP then posible du to restricted air flow.

BY matching the piping to the sizes of your AFM and TB you maximize your air fow and HP. The grater the length of this pipe = the grater amount of volme containd and thus resulting in more presure and or vacume to flow at 100% cfm's.

Take a straw and blow in it see how much air you sent through it? now put 3 straws together and now blow through them. You are blowing the same amount of air b/c your maximum inlet and outlets are the same but it is requiring you to blow harder! You have to blow harder b/c you have increased the maximum ocupancy of your item. Thus a longer piping will result the motor to have to pull much harder to get the maximum amount of air this not being generated untill a higher RMP.

Now if we shorten our item we rech maximum cfm at a much lower rate. You se here you are springing your motor to life with 100% CFM air flow immediatly and peaking it out befor you intended. A longer draw is taking more RPM to turn this gives your power curve a flater bottum and a higher top if you shorten it your curve is going to peak quickly and drop off faster. Your top HP is increasing in this setup b/c you are getting colder air .12HP per degree in F

MARTIN

Lol I agree

iceblue

It must be a bit chilly where you live. The only place I know that phisics does not exsist is in -300C I have never seen a place that cold.

RX-7Havik try this move your AFM and filter as close as you can to the TB yielding your overall setup lengh much shorter and then let us know what happens.

NZConvertible

Some people have been around for a lot longer than you too, and as a result have a much stronger understanding of fluid dynamics and how engines work.

Wrong. Removing a restriction elsewhere (e.g. the exhaust) would result in more airflow through thre entire engine, including the airbox. And the smallest part of the airbox is the same size as the AFM inlet, seeing as how they're bolted together.

If you're talking about the stock rubber intake duct, it already was the same size as the AFM outlet and TB inlet.

That has nothing to do with the volume of the pipe! A longer pipe has greater surface area, and it's the friction between the air and the pipe surface that causes resistance to flow. BTW, "occupancy" usually refers to the number of people of a room or building. It does not mean volume.

Exactly what does pipe length have to do with his intake anyway? It's about the same length as stock.

This is just a load of meaningless dribble. It can't even correct it, because I have no idea what you're trying to say.

Holy crap, that actually made sense, even if the number is wrong...

So that the filter only sucks hot underbonnet air? Yeah, that'd be a real improvement over the outside air it's currently sucking in.

RotaryEvolution

iTrader: (30)

he does have a point though, even though some of his info is wrong. the extra amount of air coming into the engine could cause the engine to be running a tiny bit rich at lower RPMs and picking up the slack at higher RPMs, if he had a way of tuning the fuel it would be more efficient all the way around.

the length of the pipe can affect how the throttle reacts to quick throttle applications because it is adding a volume of air to the intake, measured air which takes longer to reach the engine, these changes should hardly feel noticable though... it doesn't take but a millisecond for that air to travel the extra length.

sar

iTrader: (1)

Isnt the air flow meter still going to meter the same amount of air?

I've detached my air filter assembly completely and had neither rich nor lean conditions haunt me - granted i didnt exactly drive around long like this, but it was interesting.

To answer the question: You do not need larger injectors, keep in mind that using an s-afc to lean out the mixture actually tends to increase. I can't explain why you feel as though your power has changed, i doubt ram and cold air are going to change your whole 140hp and 138ftlbs by a substantial ratio that will make you unhappy or happy. On the ricer scale air filters give a 10-16hp gain... and that is generally a slightly skewed version of reality.

Where is the picture of your set up?

NZConvertible

You do understand how EFI works right? The AFM measures volume flow, the temp sensor in the AFM measures the air temp and the ECU calculates the required amount of fuel. If the airflow is a bit higher, and/or the temp is a bit lower, these changes are measured and the ECU acts accordingly.

The distance between the AFM and engine has not changed, so this does not apply in this case.

This is such a simple and common mod. Why are people acting like he's done something new and unproven, and trying to come up with possible weird results? Geez, it's just a cold air intake.

iceblue

You all are looking far to much into my post and making it to complicated. Just to try and finde a way to prove me wrong. So far I am the only person to even give the dood and axsplanation befor trying to attack my awnsers provide him with a relavant awnser as well. Or show even a theory of where im wrong.

All I can say is test it yourself. From what I see ither your over looking the entire way an engin works or just dont know.

This is what I see. STOP thinking as HP as a number or a mod of HP as a number. A engin any engin has a curve line. Evry single mod you do increases HP or lowers it and same for Torque. If you add a mod to your car you gain a number or lose or both somehwere in the RPM range. Its not like in one spot. A mod changes the way your entire curv goes. Thus if this application dosent realy take advantage to a higher RPM the curve will change more in that area thus in this application in high RPM's he notices a much grater curve in his HP then he does at a lower.

I was giving an exsplanation of what happens to air in a tube and why his car can react to it differently.

Yes opneing hte exhoust or so forth enables you to flow more air. I dont car if your exhoust is 45in and 2in long you still can not flow any more air then your weakest point in the entire engin process. If your inlet is .5in for the intake you will never flow more out your exhoust then is posible with .5in inake of air.

If he used 3in pipe to is AFM from filter and a 6in pipe from AFM to TB you will have a big lag. one you can not get more air in there then 3in as well the AFM is reading for 3in of intake now the air must fill a 6in volume befor he can start pulling air in at a maximum of 3in of volume considering his engin internals and exhoust allow for full 3in volume of air to pass through it.

NZConvertible

I did not need to look hard to find ways to prove you wrong. If you have issues with my responses to your post, then let's hear them. You can’t just complain about your answers being "attacked". If you think anything I said was wrong (and you obviously do), then say what and why.

You seem to be ignoring one very simple point. This is a very common mod on these cars and many others. Many people here have done it or something like it, and had no problems. It's not something new or weird. The symptoms described are not problems usually caused by this mod, so your attempt to explain them made little sense.

What you're explaining is a pretty simple concept. I'm pretty sure most people understand it. But the thing with a simple mod like a cold air intake is that is does effect the engine's performance right through the rev range, because the effects of lower temp are always there. There is absolutely no reason to expect any loss of performance anywhere in the rev range from doing this.

This is completely wrong. Fluids do not behave like that. If this were true then it would be impossible to make any gains without changing every part of the engine that air flows through. But we know that is not how it works. Put a bigger exhaust on a car and it will make more power despite the fact that the same airbox is there. Change the airbox for a pod filter and the engine makes more power despite the ports being untouched. The smallest part of a system does not make the system flow as if it were all that size. Forget that idea now.

Probably true, but that's not what he did, so it's not relevant at all.

You're wrong about that again. The AFM does not measure "3in of intake"; it measures whatever air passes through it. The S4 AFM inlet is 63x50 (equivalent area to 2.5" diameter), so your theory falls apart right there.

RX-7Havik

I will try it. It makes sense to me Iceblue. I'll be honest about my results to everybody.
Pics are coming.

NZConvertible

Don't do it, it's a bad idea. If you don't believe me, look around the forum at the way others have done it. Many have done it the way you have (most successfully) but nobody has been foolish enough to think moving the filter closer to the hot engine is a good idea.

iceblue

NZConvertible I know your reputable hear but I have to say you are compleatly wrong and taking my awnsers out of contaxt. Frankly what I said is compleatly right and the knowledge is taken compleatly from race proven macanics with many natinal titles under them and there motors. I care to less to try and exsplain it further or brake apart your replays. My opion why dont we wait and see what RX-7Havik has to say about his results and go from there.

ultradef

Wow. Just wow. I'm speechless.

The newest ebay trend: The Hot Air Intake. Guaranteed to lose 13 rwhp!

JinZemog

Havik, you broke something when installing your cai.
Its that simple.
You didn't just magically change your whole torque curve by putting a damn cone filter on your car!! The fresh air intake gained you 5whp and you messed someting else up when installing it. Now, change your oil, replace your sparkplugs and do some research on your car.

MARTIN

first of all, your theory is completly incorrect... I dont know what team let you work for them but I wouldnt let you work in a tire outlet.... you are saying that if you have a 1 foot long 3" pipe with a 2.5" nipple at the end of it, that it would flow as if the whole pipe was 2.5. The truth is that even if there is a reduction in diameter, the setup will still flow the same ammount, the only difference is that it will be at a greater psi...

iceblue

Only if you increase PSI. Then you are compresing air like a turbo to flow more then naturaly. If you cant see how this works anyone who this applys to you realy should find a new hobby

End3r

Lack of basic car knowledge aside, I would probably disregard anything said by someone with as poor English skills as iceblue. I take that statement back if English isn't his first language, but somehow, I doubt it.

beefhole

iTrader: (29)

I don't get it. iceblue is wrong, yet doesn't understand despite clear explanations by everyone else who knows what they are talking about.

iceblue

It is simple I am right if you dont see ur ignorent. Why not stop posting and give some facts as well lets wait and see what rx7havic has to say when he does some more testing and that will show whats up.

NZConvertible

JinZemog

If yu want tu be beliveable wiht this argument izeblue.....
Then at least try tu speel correctally, and rite full sentances we can reed.

kontakt

... ... ... ::sigh::

if the volume of air was a problem, then my EJ22 wouldn't benefit from the plastic air box next to the intake manifold. the box is there due to the small plenum on the manifold, it provides air instantaneously upon demand before the engine has to draw air through the whole system.

Lenght of pipe determines flow in a different manner. I will try to make a simple ascii diagram.
\|/
|ll|
|ll|
|ll|
/|\

\|/
|ll|
/|\

as you can see with the shorter pipe, air coming from many directions can flow straight through without hitting the wall of the pipe, whereas the longer pipe requres more force because it uses some of it to force the air in it's direction.

just my .02

SJ_chameleon

Thank you

muythaibxr

Installing the afm closer to the engine is a bad idea... You'll be sucking in hot air... and hot air is less dense...

Also, what iceblue says about intake length is backwards... usually longer intake causes more tumbling, so is decent for low-end torque because it helps mix the gas and air better... and shorter intake is better for high-end, because it can flow more air. But if I remember correctly, both of these usually refer to intake runner length on the manifold, and not the intake length in front of the throttle body.