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I have a few friends with imports mainly Honda's that have said i shud remove the air box resonator to more or less improve the sound and maybe the performance just slightly if at all.. Is removing the resonator worth doing even for just sound improvments, and secondly is ther any potential negative effects for the motor by doing so..? thid i my daily driver and im a college student without a ton of money :rolleyes: ..lol..

thanks in advance..:thumbup:
 

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it will make it louder. my first custom intake for my car I removed that box, and drilled a 5 1" holes around the bottom side of the box to alow more air into the prefilter side of the box. I did not notice any appreicable hp gains. but did notice alot more intake noise. what might make more sence is, k&n make's a cone filter with a opening that fits right on the maf housing. so you can make a basic short ram intake with your only investment being a filter. that is the setup I ran on my car for a long time after I tried cai's and other short ram intakes.

here is a pic of my old setup



good luck
 

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When I got my ZX3 the resonator AND snorkel were off (I think the previous owner had a CAI and just slapped on the stock airbox to trade it in). Anyway, I've acquired a stock snorkel and I'm trying to figure out what to do about the resonator. I'd like to do something performance-oriented, and based on what I've read here and elsewhere, the Iceman intake incorporates an SVT-like pipe that attaches where our stock Zetec resonator is on the side of the airbox:

http://www.myfordfocus.com/how-to/ice-man.htm

From that link I found THIS tutorial on a cheap and easy way to make your own Iceman tube to replace your resonator:

http://www.myfordfocus.com/how-to/ice-man-clone.htm

Later I came across THIS thread which might be of further interest to you:

http://forums.focaljet.com/zetec-tuning/578619-swiss-cheesing-airbox-need-help-2.html

I'm personally not a fan of the idea of "swiss cheesing" the bottom of the airbox, because the only thing that will do is allow the intake to suck in hot air from right next to the engine -- and hot air isn't what you want to be sucking in. What you want to do is find ways to get COLD air to your airbox from OUTSIDE the engine bay. To that end, THIS post in the "swiss cheesing" thread caught my eye, and I think this is the route I'm going to take to create my own homemade "Iceman" resonator replacement (it looks EXTREMELY cheap easy to do if you have a Dremel tool, and the end result has a clean stock look that looks very trick at the same time, IMO):

http://forums.focaljet.com/6527663-post32.html

Here's a link to the pictures that I'm going to try to emulate:

http://cid-5b2a6e30d8c06fda.spaces.live.com/photos/cns!5B2A6E30D8C06FDA!119/

Here's a pic from that site showing what the intake looks like in place of the resonator -- pretty cool, IMO:



Trick yet very clean -- and if you want something even more "custom" looking you could always paint the airbox and the new intake to give it more of an aftermarket look.

Hope this helps a bit!

FWIW, I can't comment on what removing the resonator does for the sound, because I've never heard my Zetec WITH the resonator, and my car came with a "******* cat-back" consisting of a straight pipe after the flex pipe and a TINY "muffler" at the end (smaller than the stock "lunchbox" resonator, if you can believe it!). As a result, my Focus is noisy as heck -- I feel like a boy racer every time I drive it. Thankfully, I've got an OEM SVT cat-back exhaust sitting in my garage, and I'll be getting THAT installed this week.

I will say this: Don't remove your snorkel -- my performance IMPROVED once I replaced the missing snorkel. Also, as cool as CAI setups look, my research indicates that the BEST-PERFORMING intake for any normally-aspirated Focus (SVT or stock) is either the SVT airbox and snorkel, or the stock airbox with an SVT snorkel and an Iceman-like side-tube. I don't have the links handy at the moment, but there were some posts here that showed extensive testing with various intakes, and only the Volant came close to out-performing the stock SVT airbox and snorkel arrangement (and the Volant is essentially just a "trick" variation of the stock airbox).
 

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Good link -- I kind of forgot about the HRW intake mod because I I noticed that it simply involves running an intake tube from the resonator without even removing the resonator, which leaves you with only the small rectangular resonator hole, plus the resonator box itself to add turbulence and restriction to the extra cool air being brought in. The gains shown are indisuputable based on the numbers, but it still seems like it might not be the MOST efficient mod. I think the "Jimmy_Dean0" mod (hereafter referred to as the "JDO" mod) might give even better numbers because it involves opening up the rectangular resonator hole to a full 3" round hole, which would provide for even more cool air:



Here's what the inside of the airbox looks like:



Something like this might offer even better gains than the HRW intake mod alone.

It would be cool to see some numbers using the JDO mod which removes the airbox and enlarges the hole, combined with the tubing routing method used in the HRW mod.

All of these solutions offer good gains for very few $$$ -- good stuff, no matter what you decide to go with!

:thumbup:
 

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jbodin said:
It would be cool to see some numbers using the JDO mod which removes the airbox and enlarges the hole, combined with the tubing routing method used in the HRW mod.
Did a little thinking about this today while planning out my own version of the JDO mod, and it occurred to me that combining the resonator delete and larger opening from the JDO mod with the tubing routing of the HRW mod might result in an intake "bypass" of sorts, at least at high speeds (and this could be even worse if you're using an Iceman snorkel or an SVT snorkel, which are larger than the stock snorkel).

Consider that the snorkel up front sucks air into the airbox from the bottom -- then consider that the large opening of the JDO mod combined with the HRW tubing routed to the cowl area . . . visualizing the possibly airflow path, I could see air coming IN from the snorkel and then being sucked OUT through the HRW tubing going up to the cowl area. If something like that were to occur, it could lead to considerably LESS air being sucked through the filter and into the intake, which would NOT be good for performance.

Given this possibility, I'll probably route my JDO tube forward, towards the headlight area.

Something for others to consider -- it would be interesting to see the results if someone gets brave enough to experiment with this, though.
 

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Broke_Two_Foci said:
it will make it louder. my first custom intake for my car I removed that box, and drilled a 5 1" holes around the bottom side of the box to alow more air into the prefilter side of the box. I did not notice any appreicable hp gains. but did notice alot more intake noise. what might make more sence is, k&n make's a cone filter with a opening that fits right on the maf housing. so you can make a basic short ram intake with your only investment being a filter. that is the setup I ran on my car for a long time after I tried cai's and other short ram intakes.

here is a pic of my old setup



good luck
Do you remember the part number for the K&N Cone FIlter that bolts to the existing maf housing? I think this would be a good simple set up for my 2000 ZX3...

Thanks
 

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i dont rember the part number. I will look at it this weekend and see.
 

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:eek:

Hit a deer, huh? There ARE easier ways to remove the resonator, you know!

:D

I kid! I kid!

Sorry to hear about your misfortune -- hopefully your Focus will come back no worse for wear!
 

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maybe, but remember that the cowl area is a high pressure zone. Maybe not as much with a steep windshield as in the focus, but that is where NASCAR cars get ALL their air for the engine!

When the air coming from over the hood must change direction, and fight oncoming air flowing against the windshield, it creates a high pressure zone. Now I am curious if it works on a mostly stock focus!!
 

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Hmmmm . . . didn't know that about NASCAR cars. Interesting. Good info, Brian -- thanks!

So if the cowl IS a high-pressure area, the intake routing of the HRW mod combined with the enlarged opening in place of the resonator with the JDO mod really COULD show some impressive gains as an intake mod. I think I'm going to have to play around with this one a bit (and my ZX3 is bone-stock at the moment, so if it makes a difference it should show up on the finely-calibrated "butt-dyno").
 

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a butt dyno would be the only place you would see an increase. on a regular dyno there would not be enough air flow across the hood to create the high pressure area at the cowl. and yes it works on the focus. try roling your window down just a little bit, then with the ac on outside air you should feal air flow through the vents. the ac system picks up air at the cowl on the pass side.
 

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Okay, I've been thinking (always a dangerous thing) -- once you remove the resonator and enlarge the hole to implement the JDO mod, it looks like there's still enough room to provide for an opening for a 2" (or so) opening that could potentially accomodate a duct for the HRW mod. This would enable you to have a forward-aimed JDO mod duct AND a tube routed to the cowl to incorporate the HRW mod. This is what I'm envisioning:



The JDO duct would work as an additional cold air intake port at lower speeds while taking advantage of some slight "ram air" effect while in motion, and the HRW tubing would take advantage of the high-pressure effect at the cowl area at speed as well. By extending an inlet tube into the airbox slightly for the HRW mod (perhaps just a little 1" stub angled to point towards the filter above), I think you would avoid any "bypass" effect that might occur from the forward-facing JDO inlet and the rearward-facing HRW inlet at speeds where there wasn't enough cowl pressure to allow for induction through the HRW inlet.

I am really fascinated by the possibilities here. The gains might be miniscule, even through the tried-and-proven "butt dyno," but the coolness factor would be high enough to make it worthwhile, I think. Now I just need to locate a spare lower airbox so I can start hacking away with my Dremel tool.

:cool:
 
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