Cold Air Intake


Asked by Aug 02, 2011 at 04:54 PM about the 2004 Ford Focus ZX5

Question type: Car Customization

Paying over $500 to replace the compmlete air filter box assembly is nuts ! I'm considering fitting a K & N cold air intake; what if any problems will I have with that?

24 Answers


I think you said I won't have a problem as long as I do not over oil the that right? Which K&N model should I install: Model 63-1101 or 69-3512 TP ?, or does it matter? the 63 series promises a few more HP and it's polished aluminum for the Boy-racer look under the hood, (it's also an extra $31 to buy). Charles

you should have no problem with cold air induction,thing is the filter clamps on end of tubeing,you dont oil it,you just take it off(filter)and wash it out with a waterhose.let dry reinstall.the K&N filters that are oiled is the round ones that replace a regular air filter,the round ones.


if youre going to buy a cai to get performance gains then dont buy K&N. if youre buying it to save money from replacing the stock system just get the cheapest one and be done with it.

4 of 4 people found this helpful.

Ok, I've seen K & N and AEM, are their others? NO performance gain, get the cheapest. I DO want some performance gain so which system is it?

1 of 1 people found this helpful.

Ok, I've seen K & N and AEM, are their others? NO performance gain, get the cheapest. I DO want some performance gain so which system is it?


join a ford focus forum. once in there do a search. they should have plenty of info for the best system available.

2 of 2 people found this helpful.

Go with the K&N CAI,will increass your HP by at least 5%.

1 of 1 people found this helpful.

Lol that's a good one.

1 of 1 people found this helpful.

you going to start now.DONT.


You gave false information. k&n system will not give him 5%. There's better systems out there. I told him where to go to find them. Leave it at that.

3 of 3 people found this helpful.

it will give it 5% or your homework.leave it at that.I warned you chase dont start.


It will give 5% you claim with a dyno tune where the hood is open because the cold air intake is actually a hot air intake. Real world application (what the driver actually sees on the road while driving) has huge issues with heat soak and raised IATs which cause retarded timing. Critical loss in power on the road. K&N will not give him 5% or more. Stick that Homework where the sun doesn't shine. Argument over. Now let it go. You were wrong.

1 of 1 people found this helpful.

Chase you real funny,now stop trying to be like your buddy,JL.if you can read look at the instructions on a K&N,CAI,it WILL tell how much gain in HP it will give a vehicle 5% or more.I asked you nice not to start with me.UNDERSTAND.


im not messing with you. im telling the OP that you are wrong on this subject and not to listen. so let me get this right...since K&N tells you it will give you an increase of so much you actually believe them? you do realize that their claimed gains are done with tunes to maximize hp readouts right? the K&N system on the 300C/charger/challenger and gto has actually been proven to perform worse than the stock option or at the same level as the stock option on the track. you do understand how tuning works dont you? do you know what heat soak is? do you know what IATs are? this is one subject youre wrong in. cant be right about everything.


sorry about the argument with this guy. i just didnt want you to be misinformed about the performance of certain products. just because they say it will gave you some crazy number doesnt mean it will. i think most people in the performance world know parts rarely make their advertised power. good luck on whatever decision you make


No worries Chase, Whichever way I go with this, K&N, AEM, FW Werks, Weapon R........I appreciate the feedback. Now do you have any comment regarding aftermarket exhaust systems?


By exhaust systems what are you looking for? Do you want an entire system? If you're just thinking a catback you will have minimum gains. Basically all aftermarket systems give roughly the same power gains. You can choose one based on sound. For maximum gains you would be best off in getting a full system. Header, high flow cat, and catback. Again I'm not positive on what systems have the best fit for these cars so you would be best off checking on a forum. Personally if kooks, stainless works, or American racing makes a header for your car I'd go with them. Great companies.


Lmfao. Now you recommend chokemasters? They are not the least resitrcitive on the market. not even close. Their systems do still make good power though. Right now par with any other aftermarket exhaust systems. Again feeding false information. I believe maybe you've been a tech who works on repairing cars but that doesn't make you any sort of master when it comes to aftermarket performance. And that's clear.


btw here is an INDEPENDENT study done on a large amount of different mufflers. check where chokemaster fits in. like i said you might know what you are talking about when it comes to repairs but when it comes to aftermarket you dont. The results in HP order: 1.Flowtech Warlock (open) 374.2 hp/ 333.1 tq 2.Bassani Real Street 373.7 hp/ 333.8 tq 3.Hooker Maxflow 373.5 hp/ 333 tq 4.Borla XS 373.3 hp/ 332.6 tq 5.Magnaflow 372.8 / 332.5 tq 6.MAC 372.3 hp / 331.5 tq 7.Flowtech Afterburner 372.3 hp/ 330.1 tq 8.Hooker Aerochamber 372.1 hp/ 330.4 tq 9.Bassani 372 hp/ 333.5 tq 10.Spintech 371.6 hp/ 332.2 tq 11.Edelbrock Performer RPM 370.9 hp / 331.3 tq 12.Borla XR1 370 hp/ 334 tq 13.Flowtech Terminator 369.5 hp / 331.3 tq 14.Dynomax Ultra Flo 369.4 / 333.2 tq 15.Flowmaster 369.4 hp / 331.8 tq 16.Flowtech Warlock 366.3 hp / 325.3 tq 17.No muffs 365.2 hp / 330.1 tq Sound Off in Quietest to Loudest (Decibels): 1.Borla XS, 80db at idle, 90db at 2,000 rpm, 110db at WOT. 2.Hooker Maxflow, 80db at idle, 90db at 2,000 rpm, 120db at WOT. 3.Magnaflow, 82db at idle, 91 at 2,000 rpm, 114db at WOT. 4.Flowmaster, 82db at idle, 93 at 2,000 rpm, 115db at WOT. 5.Flowtech Warlock, 83db at idle, 92 at 2,000 rpm, 112db at WOT. 6.Dynomax UltraFlo, 83db at idle, 94 at 2,000 rpm, 113db at WOT. 7.Borla XR1, 83db at idle, 96db at 2,000 rpm, 118db at WOT. 8.Bassani Street, 83db at idle, 96db at 2,000 rpm, 120db at WOT. 9.Edelbrock RPM, 84db at idle, 93db at 2,000 rpm, 118db at WOT. 10.Bassani Real Street, 84db at idle, 96db at 2,000 rpm, MAX. (120+db). 11.Flowtech Afterburner, 86db at idle, 94db at 2,000 rpm, 115db at WOT. 12.Flowtech Terminator, 86db at idle, 94db at 2,000 rpm, 119db at WOT. 13.Hooker Aerochamber, 87db at idle, 94db at 2,000 rpm, 114db at WOT. 14.SpinTech, 87db at idle, 97db at 2,000 rpm, 116db at WOT. 15.MAC, 87db at idle, 98db at 2,000 rpm, 119db at WOT. 16.No Muffler, 91db at idle, 103db at 2,000 rpm, MAX. (120+db).

what is this,1 independent study.Google search,real cool.CHASE,stop this now befor it gets out of hand,like it did with your banned buddy.I dont have time to BABY SIT here.just give it got your opinion,I got mine.leave it at that.


If you go ColdAirIntake, make sure you buy a Bypass Valve so that way water does get into your engine if your system has your filter below your engine like mines. If the system has your filter where you old air box was, aka ShortRamIntake then you shouldn't experience any problems at all. Just get ready to enjoy your car's new attitude.


Shouldnt have any, I recently did mine with Spec D cold air($50 kit) and it worked like a charm, better than the k&n short ram($90 kit) it replaced. I would buy the Spec'D piping and use K&N filter, its a little cheaper that way. Install is damn easy though


Chase, your right. and no intake can guarantee 5% gain on every vehicle, not even most. it does require dyno tuning, and for a guy who had some done a few months back to his 89 XJ6, i can tell you for a fact I got less than 3% HP off a K&N CAI. Charles needs to go away with his false info, K&N isnt god...


Steeda makes the best intake for the best price. FSWERKS also makes a good intake. If you are looking for a good forum you can go to the Focus Fanatics. You wont get a 5% hp gain, you might get a 5hp gain, but normally it will help with mpg. I put a steeda intake on my 08 and i got a small power gain and 5mpg higher average on the highway.

1 of 1 people found this helpful.

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