I have purchased the comptech headers and AEM intake with bypass valve for christmas, Im getting them installed on the 26th!!! Do I need to break in the headers or what? Also I've been quoted on 385 dollars for the installation, for everything, (bypass valve, headers, AEM intake) Is this too steep? Im working on it with my general manager buddy at ACURA to get it done hopefully.

Nick

 

there's no moving parts in the headers so you don't need to break anything in.


headers and intake like you will :P

 

You'll have to check the torque on the header after a while.

 

The headers take about 2 hours to install (depending on experience of the dealer); the Intake installation runs around $50 to $75.

(The quote above was from the Acura dealer that did mine with a shop rate of $70/hr [no AEM bypass])

If you must have the bypass valve installed (I see your up north), see about getting a spare 3" hose and 2 hose clamps to replace the "valve" in the summer. The bypass valve (in a hot engine compartment under WOT) can negate any advantage of putting the CAI in there in the first place...

$0.02...

 

uh, that's a no.

looking at the stock intake, it draws air in from the engine bay (courtesy of that 'U' tube). it looks like if the resonator is removed, it will draw a little bit from under the engine bay, but still mostly hot air.

w/ the bypass valve, under WOT, if they open, it still draws most of the air through the main filter and a tiny amount through the bypass, if any, but not enough through the bypass to even remotely negate the CAI effect over a stock intake with the resonator removed.

 

uh, please have a look at the link below some additional information.

Get a bypass valve and give a test -- I have it in the box here and did some tests... (I spent a bit of time checking on under hood temps and called AEM [and others])...

IT was AEM Tech support that told me to install a hose to replace the bypass valve in summer -- and that was just due to the turbulence issues.

You can run a marathon with that bypass valve over your mouth (with one end blocked) and you would have no problem breathing through it (and only a little trouble breathing out of it). It opens into the VERY hot air at the top of the engine's hood. At WOT, there is vacuum in the entire pipe. The worst case is when the car is sitting at a stop light on a warm day with the hot air temps rising from 140 to 200 degrees F (or more). There are a number of people who have already done tests of under hood temps (in non-dyno situations). That's the part that people don't understand.

The engine temperature gradient from the bottom-to-top gets rather confused (turbulent) once the car starts moving. However, during static conditions, there is some turbulence caused by the hot air rising and the temp gradient from top to bottom is not completely uniform. However, the further up you grab for air, the hotter it is. The bypass valve is mounted at one of the hotter locations under the hood (outside of sitting next to the headers).

Read this before you get your mind too "stuck" (remember, I have an AEM CAI and purchased a bypass valve that is not going on now – hmmm…)

(AEM bypass valve -- some thoughts...)
http://www.acura-cl.com/forums/showt...threadid=55395

I just spent money for the cleaning kit, bypass filter, and spare filter (for “cleaning sessions”) -- you tell me what I have to gain by pointing out info that makes me look foolish for buying the valve I was going to install. I also spent a good deal of time checking the info out. (It was the very experimentation with the valve that led to my lack of enthusiasm with it!)

 

1) my bypass valve is mounted right where the hole is that goes to the underhood compartment.

2) ericl sent me a pm about this, so i'm going to use numbers he provided, namely that under wot, 20% of the air mixture is from the bypass valve.

3) if you look at the stock intake, there is a lot more turbulence caused by it. there is the U-pipe, which draws air in from the engine compartment (hot air), there is the resonator at the bototm of the U pipe contributing to tturbulence, there is the big square airbox and filter, which contributes to even a lot more turbulence, and then this all goes back into a round hole into. so which would contribute more turbulence? a stock intake with all those round to square profiles, or a CAI with a bypass?

4) if you remove the resontator from the stock system, then it may draw a little cold air from under the compartment, but it's a tiny-ass hole, so maybe 10% (if that) of the mixture would be cold. according to ericL, w/ a CAI and bypass under WOT, 20% of the mixture is from the hot engine compartment. i think the bypass valves is mounted differently on xephyr units (right above the hole on the bottom of the engine compartment. now what would you rather have? 20% hot air and 80% cold air, 80% or more hot air and 20% or less cool air?

im' not arguing there isn't a loss when comparing a CAI w/ a bypass to one w/o a bypass, 'cuz there is.

but how can there be a loss between a cai w/ bypass vs. the stock intake, when all the arguments about losing power can be applied to the stock intake, except to an even greater degree?

 

This is now starting to get interesting. EricL or whomever, dyno's of OE intake, and AEM w/bypass would give us what we need. As I'm in the same boat with you, bypass unit sitting in the garage.

I'll search both sites for a bone stock dyno. Somebody help me here and find us an CAI / bypass only dyno (or go make us one!)

 

All I have to say is that someone with an AEM (w/ bypass) should race me in the summertime and if Eric's theory about it pulling hot air into the intake is true, I should be able to pull on them since I'm getting cooler air from down bottom.

 

There are two extreme conditions worth considering:

Colder air from the car’s front infiltrates into the engine compartment through a modest size hole. This hole is getting its air from the front of the car and the air pressure at the front of the car is proportional to velocity^2.

Hot air rises and the bypass sits near the top of the engine.

For example – if a car were sitting in 90-degree heat waiting to do a drag run, the under hood temperatures near the location of the bypass valve gets extremely hot. If this same car is in slow traffic or idling for a long period, it will also have very high temperatures next to the bypass valve; it should be mounted high on the pipe [as it is on the Xepher and on area downside of the 90-degree bend on the AEM].

Alternate example(s) – if a car is moving a 65 MPH or if it on the freeway, there is more air mixing in. There is a point, where the car is finally moving fast enough that there is only a small increase in the temperature (compared to ambient) near the hood with enough velocity.

So, in one situation, the bypass valve will have minimal impact of the performance of the car. In another situation, where the car has been sitting a while (like at a drag strip) the hot air will take a while to mix with the colder outside air.


RE: “Let’s just settle this and run some dynos” – sure great idea…but…

However, the problem is knowing how the cooling air and fans were placed during the run(s). Was the hood closed? If so, how long? If the hood is open and the dyno operator brings in 2 or 3 giant 480V 3-phase AC fans, how accurate does anyone think the test will be for simulating the actual temps during various “real world” conditions?


IMO -- There are some circumstances where a stock system could actually outperform an AEM intake w/bypass or a Xepher system. That small opening near the splashguard with very cold air is not all that far from the opening of the stock intake or the two CAIs. The transient condition is hard to model on a dyno. Before this turns into flame city – think about it for a while (more than a few minutes). With a quick stomp on the gas, the opening towards the front of the car provides a mild “ram” effect and it will get cooler in this area before the top of the engine compartment.

Finally, there is that nasty issue about dirt getting into the engine through that foam element on the bypass valve.