88rxsedan Posted March 7, 2004 Share Posted March 7, 2004 im telling you the truth, the freaking car has way more high rpm power now.. Quote Link to comment Share on other sites More sharing options...
baccaruda Posted March 7, 2004 Share Posted March 7, 2004 yeah.. if anything, i'd question the CFM rating. and i wouldn't be surprised if the dramatic difference is only to be found on a naturally aspirated subaru, and the turbos get the real benefit. Quote Link to comment Share on other sites More sharing options...
MaroonDuneDoom Posted March 7, 2004 Share Posted March 7, 2004 The nice whooshing sound it produces after being cut is well worth it. The exhaust note will change too. Definitely to my liking. Even if it doesn't increase horsepower, you can feel the difference the first time you drive it. I think that the difference felt is not more power, but faster access to said power. Of course the engineers who designed the car wouldn't make the intake insufficient, but i think it can definitely be improved on. Just remember, the less restriction the better. The only drawback is the fact that the filter gets dirtier a little faster. Water is not an issue. You'd really have to try to get the filter wet. Stays nice and dry. Quote Link to comment Share on other sites More sharing options...
calebz Posted March 7, 2004 Share Posted March 7, 2004 I also experienced what rob did. after removal of the bottom of the airbox, my T-wagon was able to pull all the way to redline. it would 'run out of breath' before. I most definitely question Noah's numbers on this. Its nice to be able to say ' a certain mod only produces X amount of gain ', but it would seem very strange to me that so many people have had experience that contradicts this. Noah. Did you flow a turbo car? and what was your method? Quote Link to comment Share on other sites More sharing options...
MilesFox Posted March 7, 2004 Share Posted March 7, 2004 the RX hits a "second power curve" at 5000 rpm, you can hear the turbo and all, chopped BOTTOM of the airbox. we just did jims. i makes a nice grown when you crack the throttle open AIR FILTER DEBATE: k&n claims their filter flows as well as paper filters, but the advantage is you can cleqn and re-use it so with the open box, if you are prone to clog the filter quickly, that is where a "permanent" filter will have an advantage(think, motorcycle, k&n started with moto's) Quote Link to comment Share on other sites More sharing options...
asavage Posted March 7, 2004 Share Posted March 7, 2004 Originally posted by MilesFox AIR FILTER DEBATE: k&n claims their filter flows as well as paper filters, but the advantage is you can cleqn and re-use it. Not quite. K&N claims performance gains from "virtually unrestricted airflow" from their products. . . . so with the open box, if you are prone to clog the filter quickly, that is where a "permanent" filter will have an advantage(think, motorcycle, k&n started with moto's) I ran K&Ns in the 70's in my motorcycles. I had a gallon of K&N reoiling oil around for years, bought it when it was a lot more expensive than it is today, and I was a lot more ignorant. I recently used it to start some bonfires, it worked great for that. http://www.knfilters.com/filtercharger.htm "Our air filter is designed to achieve high, virtually unrestricted air flow" Virtually unrestricted airflow, but without adding additional square inches of filter media. You do this by reducing restriction. OK. How do you do that? Make the "holes" larger. Larger holes = more airflow, but also more dirt gets through. Having the "holes" be lined with tacky oil does not imply that the dirt is going to stick to the oil. ". . . stumbled on a cotton filtration technology destined to be great. Our high flow cotton gauze air filter is washable, reusable and built to last for the life of an engine. The filters consist of four to six sheets of cotton gauze layered between two sheets of aluminum wire mesh. This media is then pleated and oiled to enhance its filtering capabilities and overall performance." This is the same technlogy that LawnBoy, McCullough, and many others discarded in the early 60's, because the filtering efficiency of oiled media sucks. It's even worse than oil-bath air cleaners (like VW used through the end of the 60's). Yup, it flows more air. Yup, it it cleanable and resuseable. Does it filter as well as pleated paper. Not on your life. BTW: all filters' filtering efficiency goes up as the media becomes more saturated with dirt. Yes, this means that a "plugged" air filter or oil filter keeps more dirt out of the stream -- to a point, anyway, until the pressure differential gets high enough to break down the filter substrate. "The result is an air filter that allows dramatically more air into an engine, is washable and reusable, and will protect your engine for the life of your vehicle." The reduced life of your vehicle, is what they should say. TANSTAAFL (Google it, it's classic Heinlein) Quote Link to comment Share on other sites More sharing options...
bushbasher Posted March 7, 2004 Share Posted March 7, 2004 I totally agree with asavage on the k&n issue, Quote Link to comment Share on other sites More sharing options...
NoahDL88 Posted March 7, 2004 Share Posted March 7, 2004 I did not flow a turbo car but i believe that the bottom boxes are the same for both cars, the tests were on a superflow flow bench and the machine was calibrated between each run. What it seems to me is that once someone has done this mod, they don't want to feel like punks and have it not work so they go with the majority and say that they got all this extra power from it, for instance going from 60 in 4th to 90 in 5th would be a net gain of over 50 hp, the hp needed to make that much difference between the speeds because of wind resistance. i'm not saying that it dosn't work at all but it would seem that, myself included, that after you make a mod you drive more aggressive, which in itself will make the car seem faster. Quote Link to comment Share on other sites More sharing options...
baccaruda Posted March 8, 2004 Share Posted March 8, 2004 i know exactly what you're saying, noah. to protect myself from being victim to that i used the example on the freeway.. with the same car, it would not accellerate out of 4th gear before the box was cut. there would have been no way to force it. after i cut the box, and on a later trip across I-90, on the same hill, the car was going 90 in 5th and it wasn't quite done accellerating when i decided to behave myself, since i'd just wanted to see how the engine pulled this time. that's why i'm pretty sure i wasn't just wanting it to be fast. plus, a turbo is a compressor. i don't know if flowbenches can compress, but the limits to how much air a turbo could draw through the intake, and how fast, are the size of the intake and how much compression the engine can tolerate. the entrance to the airbox thru the intake silencer is an oval the same shape as a deodorant stick's. eliminating the impedance of the intake muffler and enlarging the airbox entrance to a 5"x7" rectangle is a very dramatic modification (and actually a simplification if you think about it, which seems complementary to the increase ). please know that i'm not coming down on you at all, just explaining why i disagree. edit: i believe the bottom boxes are the same. hey, we could have an experiment. anyone near noah want to chop out their airbox? Quote Link to comment Share on other sites More sharing options...
MilesFox Posted March 8, 2004 Share Posted March 8, 2004 cone filters thru the hood! nuff said... Quote Link to comment Share on other sites More sharing options...
WJM Posted March 8, 2004 Share Posted March 8, 2004 with 15 for an adapter, and 25 for a cone filter, you get a good intake. way better than a stock airbox. Ive done this mod on my DL. As for the airbox cutting...it was the first mod to my RX....yes, it makes a noticable difference on turbo cars. N/A cars...not as much gain as you think...not until you get a new EJ powered sube do you notice a difference with a cut airbox. Even then, gains are minimal. Nuff said. Oh, and stiking it thru the hood is good. Cooler air. Quote Link to comment Share on other sites More sharing options...
Steveman09 Posted March 8, 2004 Share Posted March 8, 2004 Can somone post pics of thier modded box to give me some idea's? I'm debating to go either custom or do the mod. Quote Link to comment Share on other sites More sharing options...
speedbump Posted March 8, 2004 Author Share Posted March 8, 2004 pro/con I did it any ways.The pro side wins,acceleration is noticeably quicker with more power available in 3rd(3at) yippee! Quote Link to comment Share on other sites More sharing options...
the_bard Posted March 8, 2004 Share Posted March 8, 2004 I so want to stick mine through the hood. Definitely adds character. PK lifted wagon... custom bumpers, brushguard, & rack via soobme... 28" tires... and an air intake sticking out the hood. Think we can drum up some of those decals that are on the side of jet aircraft intakes? "Warning: Air Intake" Miles: Would it be possible to get a pic of under the hood? I assume that's a carbed model... I gotta figure out how to rig that up with a SPFI... Quote Link to comment Share on other sites More sharing options...
MilesFox Posted March 8, 2004 Share Posted March 8, 2004 somewhere i had a pic, if i was at my own computer right now, i could find i.... speaking of cutting the airbox, i made a MAF adapter by cutting the part of the box where it mounted, found some old exhaust pipe, cut it don the side, and expanded it to the diameter of the filter. i welded this to the mount, and therefore had an adapter. i made a little tab to fit on the screw on the back of the turbo plenum its ugly, no entirely sealed(but duct tape will fix!) but now i have the system movked up and mounted, so i can go from there for improvements right now the filter has been apsent ince the turbo motor didnt last 100 miles, had a carb, but i will use it with teh ej22 i am now working on in the same car Quote Link to comment Share on other sites More sharing options...
rallyruss Posted March 9, 2004 Share Posted March 9, 2004 ok so all this debate made me think of a compromise mod. what if instead of hacking the bottom out you made the opening to the fender (cool air) bigger with the silencer removed. this should give me at least 20hp for doing it first. mabey another 5hp if it looks good too. ok Im off to the garage. :cool: Quote Link to comment Share on other sites More sharing options...
Meeky Moose Posted March 9, 2004 Share Posted March 9, 2004 well i can say that there is a noticable difference in how the rx revs, and how high it will rev.. i put a cone filter on it very nice imo.. deffinitely worth it.. now on my spfi wagon i took the airbox off and replaced it with an MRT cone style filter (made down under) its hella loud, but i didn't really notice a difference in power.. maybe a little better acceleration past 5k but not enough to make the gain offset the sound.. so its gettin a stock setup again when i do the tranny.. Quote Link to comment Share on other sites More sharing options...
speedbump Posted March 11, 2004 Author Share Posted March 11, 2004 actually,the most important thing I did was blast an dpolish the intake plenum and paint all but the top machined area wrx blue! good for at least 20 ft/lb of torque! Quote Link to comment Share on other sites More sharing options...
rallyruss Posted April 14, 2004 Share Posted April 14, 2004 ok so all this debate made me think of a compromise mod. what if instead of hacking the bottom out you made the opening to the fender (cool air) bigger with the silencer removed.this should give me at least 20hp for doing it first. mabey another 5hp if it looks good too. I did it finaly. I busted out the sawsall and made the hole bigger. air box and body. sealed off the gap to the engine compartment. test drive felt really good. dont know if I can claim any actual power increases but it sure pulled hard. ok so thats my idea of a good cheap air box mod. no hot air here. Quote Link to comment Share on other sites More sharing options...
bushbasher Posted April 15, 2004 Share Posted April 15, 2004 I pulled out my silencer when I took off my fenders, and put a screen in the opening so gravel and junk wont make it into the airbox... Throttle response is noticeably better, It no longer hesitates for a split second when I punch the throttle hard. My dual exhaust definitely made more difference... probably several more feet of burnout possible now Quote Link to comment Share on other sites More sharing options...
baccaruda Posted April 15, 2004 Share Posted April 15, 2004 screen's a cool idea for the box chop. Someone a while ago compared chopping the box bottom to installing an aftermarket style intake and cone filter. I recall reading that chopping out the bottom of the box worked just about as well, because the only kind of air it got was cold air from under the car. recall that the bottom of the airbox is level with the middle of the engine, and the only way for air to get into the engine bay is through the grille and radiator or from *under the car*.. right up into the chopped out airbox! I read a comparison on airfilters a bit ago (might have been on www.bobistheoilguy.com ) and the K&N style didn't filter nearly as well as a paper style filter. Quote Link to comment Share on other sites More sharing options...
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