On a NA car, and using the Apex I intake, you think this setup would gain more HP than the standard CAI?



This post has been edited by erics1one: Apr 22, 2005 - 11:41 AM

In a word - No. Will not give you postive manifold pressure.
Gary

Would there be noticeable HP gain compared to a standard CAI? 3 or 4 maybe?

any gains you get wont be felt.

and if you do get positive pressure, you get fuel cut unless you run some check valves

On paper you'll see a gain of around 5hp w/ a cold air once you start getting into bigger hp. With a 3s setup, around 240 whp you'll see a gain like this.

cruising at about 60mph, youll theoretically get a positive pressure of about 0.06 psi. In actuallity, youll get much less due to pipe length, 2D flow effects, and heat addition from the engine

to get 1 psi of positive pressure using a ram air setup like that, youll need to be moving about 228 mph. And thats not even taking into account the losses i said above, so its closer to 250-270 mph.

If you want turbo boost levels of lets say 8 psi, youll need to drive at 623 mph. About the cruising speed of a Boeing 777.

so.... no

does it rain in Phoenix, AZ at all? because if any water gets into that intake , your ****ed...

anyway... a nice downpipe or manuel or electronic boost controller would increase psi much better than dangerous CAI set-up.

CAI in a turbo car is kind of pointless since turbo cars have intercoolers to cool the air anyway... spend the money on co2 intercooler spray, or just any regular water sprayer would provide better and safer performance increase..


Mina

This post has been edited by XXX_Mina: Apr 22, 2005 - 5:36 AM

put it this way eric.....
i ran my intake exactly like that with a k&n air filter

yo DO notice a difference
no you wont' be getting a good deal of positive pressure but what you will be doing is eleminating the vaccum to make it about 0

just stick your hand out the window having your intake completely sealed and funneling from the front of the car does help and improve performance.......

i've done it once and i'm doing it again and i won't go back to the short ram BS or the lets keep my CAI filter inside the engine bay?

go with the design you have and you'll notice

-playr158+Apr 22, 2005 - 5:53 AM

Well I'm not sure if anyone else here has tried it...but I figured that you'd notice a difference. Did you have the pocket enclosed? Or was the filter just placed in that general area? Whenever you set this up again, try an Apexi filter (supposed to have a lot less resistance) and let us know how it feels.

I know this setup wouldn't give you a strong pressurized PSI within the manifold, but was mostly curious about its ultimate effect. Not like you could dyno the numbers or anything...so not sure how you could test it...

...and Mina, I mentioned it was for a NA.

well testing is drive stock filter

replace with new setup
yea for the filter i'm goin to just go get an apc for 20$
cause i'm goin turbo in a little bit and don't really wana spend that much on NA stuff
but yea the 1st system i built wasn't fully sealed i tried and it was a biatch to do but new ideas have come and this time it will be

there is no way to create boost from a cold air intake....sorry.

*changed subject: I'm not trying to accomplish positive manifold pressure through a CAI setup. Mostly curious as to the end HP gain at 70mph+

With the filter enclosed in a sealed pocket, and using the Apex i, there has to be a noticeable gain.

This post has been edited by erics1one: Apr 22, 2005 - 11:46 AM

You have a turbo already, why do you care about ram air?

You'll get positive pressure. I'm working on proving this right now. There no way that couldn't get at least some postive pressure. Stick your hand out the window and feel the air at like 70mph. I've had these systems on 2 of my cars now, and it feels like I've got a gain with them. If they didn't work, race teams wouldn't use them, and neither would manufactors. Simple as that.

he's not running turbo super READ

and yes you did notice a gain cause it does produce a gain

but it will not create a great positive pressure it will most likely take your engine outta vaccum and make it read about 0 which is still gaining HP

-Supersprynt+Apr 22, 2005 - 10:15 AM

Just inquiring about the concept.

-Bigmeanbulldog55+Apr 22, 2005 - 10:20 AM

Exactly, we've all seen the infamous High Beam CAI. Was thinking that if there was more of a pocket for the air to get trapped and pushed through the intake, there would be a fairly decent gain. This would be perfect for the peeps who'll spend $500+ for a performance header that will give you >10hp.

Anyone have a general HP number this might produce?

This post has been edited by erics1one: Apr 22, 2005 - 12:46 PM

Like i stated, it will cause positve pressure, but nothing of any significance that will increase HP. If you want to do the numbers yourself, i simply used the basic isentropic flow relations assuming that the stagnation pressure will be intake pressure. That is actually a very very bad assumption since the flow is not going through the intake head on, but through a filter, then through a length of pipe. Even the use of the isentropic relation is not accurate since there is bound to be heat addition as the flow goes from the filter to the intake manifold past the engine. But if you want to crank the numbers modeling this as a 2-D, adiabatic flow problem, then be my guest.

Im not saying it wont increase performance, because my bet is it will. But it will be a more effective CAI and thats it. Since you are getting intake air directly from outside as it is moving, it will be much cooler than any air that you will find in your engine bay. But you dont want to 'trap' air and try to force it through the filter. Any trapped air will loose velocity and thus be subjected to heat transfer from the engine, or any part of you car. If you keep the CAI in a moving air flow, as race teams do, then you will be getting intial intake air at standard atmospheric temperature, unsubjecated to any heat transfer before entering the filter.

-XXX_Mina+Apr 22, 2005 - 5:33 AM

And this is based on what evidence? >>
CAI will make a huge difference on a turbo car. Put cold air into the system - it is then 'heated' up by the turbo and cooled back down by the intercooler. Now, put hot air into the intake system (like a cone filter would by sitting unprotected in the engine bay) - as you have a higher start point, temps at the inlet manifold will be higher overall. If this wan't the case, then why do car manufacturers have a feed to the cold air box from outside the engine bay? And why do race car builders do the same. Guess the $ I've spent redesigning the intake system on my rally car must be a waste >>
Gary

Thanks orville, you obviously know the more technical side of things as compared to my general understanding.

What I was thinking:

Intake SUCKING cold air from bay = better than stock
Cold Air being PUSHED into intake from outside = better than sucking

Still unsure of how much better it would be...1 or 2 hp maybe?

This post has been edited by erics1one: Apr 22, 2005 - 3:32 PM

-erics1one+Apr 22, 2005 - 3:31 PM


yep. the cooler the air the better, but i would worry about driving over a puddle of water and causing damage to the motor with an intake like that.

nope don't run into any water issues because just a splash won't do anything

hell i've driven in pouring down ungodly rain and was fine

the ONLY time you really run into a water motor issue is if you submerge the entire filter

....coming from someone who has actually done it

thanks player

why dont you use Co2 sprayers on the intake pipe... i think they make those... it will freeze/ cool down your pipes... and might be usefull if your engine ever catches fire...

Mina