Yes, we do. It's also one of those things that might not be restrictive at 300 crank horsepower, but if you add mods that bring you up to 330, it may have an affect. Drag goes up with the square of velocity (at least the simple models do), so a 10% increase in air velocity (which is roughly how much more air you'll need to get 10% more horsepower, at least) equates to 20% more drag (110% squared).

Am I getting my math right? (rusty..)

 

At first glance, you would think that this thing is not very restrictive... but when you take into acount all the welds and the fact that all the surfaces are rough, and not smooth... I think it maybe something to consider. I might take mine out when I get home from work. Basically, what is the general consensus here? Any reason not to take it out?

 

And M1Rifle... how did you take this thing out. I just went down and tried it here at work... don't have much to work with as far as tools. But it has that annoying lip on it, and the thing doesn't want to come out. Any hints on how you got it out? Any trick to it?

 

Yes. Just use the tips of a rat nose plier to push the rubber lips back behind the front edge of the metal cylinder. Once this rubber lip is no longer blocking the darned thing, then grab the outer cylinder (not the vanes!) of the unit with the same pliers and tug it out, a little on one side, then go around and tug some more, just keep going around the edge.

The rubber lips only overlap it by about 1/10" all the way around.

 

Ok, will try it tomorrow... thanks.

 

your kidding,that thing is the most restrictive thing i've ever seen in a auto's intake.

 

Hopefully that piece isn't necessary to achieve certain flow characteristics.....though I'm not sure what making the flow more turbulent would accomplish?

 

Man, that thing looks really restrictive...I wonder if removing it will have any effect on passing emissions tests...I'd stash that piece away somewhere in case u ever need it again.

 

I'll be putting it back in for Monday, when I drop it off at a dyno shop for a couple of days while I am on business.

I think they'll throw the hydrocarbon trap in, and stock exhaust, and take a baseline. I have Flowmaster Super40's on it now, and will be getting an SCT XCalibrator plus some tunes on it.

Details Wed/Thurs this week.

 

Can't wait to see the results. I'd be curious to know if you get any gains when taking out the trap.

 

Not sure if they will A/B test the trap alone. Also, I think the most important test would be trap/no-trap at 6500rpm (only valid AFTER a flash that increases the RPM limit)

 

I put a K & N filter on my 2004 Civic and removed all the factory stuff...shot the heck out of the gas mileage (25% reduction!). Put the stock stuff back on - mileage went back to high 30s. I'm wondering if putting on a K& N filter and removing the 'trap' will result in decreased gas mileage for my GT. I understand getting the car to breath and exhaust better results in more HP, but what about the affects on mileage?
:scratch:

 

I can't speak to your 04 Civic, but any removal of intake restriction will cause you to have better gas mileage.

Removal of exhaust restriction is a different story, since exhausts are tuned to scavenge unspent gasses, which increases MPG.

This does NOT include catalytic converters, which do no scavenge unspent gasses, but rather keep carbon monoxide from exiting the tailpipes. Cats hurt both MPG and HP, but help out in keeping the emissions low.

 

I pulled my HC filter out today and noticed that the filter itself looked a like it was a bit clogged up with what looks like a dry'd up white clay like substance.

Anyone have any idea what I might be looking at?

Also I noticed my car idle's a little bit higher. Say around 500 RPM.

Does anybody know if removing the HC filter will affect the air flow sensor, creating a need for a tune?

One more thing, the exhaust sounds a little deeper without the filter.

By the way what is the overall consensus on this topic. IN or OUT?

 

Let me give you my experience. I took my automatic '05 to a local shop, Delk Performance, to get a bone stock baseline. They have a Mustang dyno, and on the first 2 pulls it registered 255.3hp/265tq, 255.7hp/267tq. With no other modifications other than the removal of the HC trap, the next 2 pulls netted 261.2hp/269tq and 261.9hp/271tq. Engine temps on all pulls were within 2 degrees of each other.

That tells me there is definitely a restriction with the HC trap. Also, I have emission tested (sniffer) my car to see if there was any detremental effects by not having it in. It made no difference.

BTW, the white "stuff" in the trap is the material that catches the hydrocarbons, not the metal itself.

 

over 2000 miles on my car now and trap was out at 300 miles.No problems at all,nada,zilch.

 

It's not an HC Filter. It is an HC trap.

The white stuff is the stuff that actually does the work. My spelling is probably wrong, but it's a ziolite. That's a mineral that has qualities such as being able to absorb hydrocarbons.

The white stuff is the part that makes it work.

I took mine out. I had it tuned with it out as well. 4-7hp.

 

HC Trap. Gotcha!

thanks for the inputs!

Think I'll wait for the intake and exhaust kits before I take her in for a tune though.

 

Your car idled lower than 500 before removing the trap? :scratch:

See this thread, most people's idle went down to 750.

http://forums.bradbarnett.net/index.php?sh...c=12046&hl=idle

 

Your car idled lower than 500 before removing the trap? :scratch:

See this thread, most people's idle went down to 750.

http://forums.bradbarnett.net/index.php?sh...c=12046&hl=idle [/b][/quote]
Mine idles at 750 stock.