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New air intake

Posted: Tue May 21, 2013 6:52 am
by Rembly
Hey Guys, pretty new to this form.. so haven't read everything and im sure the information i require is out there but i going to ask anyway.

Looking to upgrade my exhaust and air intake in hopes of getting a bit more power. someone said to stay away from short ram. wondering what cold air intake i should upgrade to?

Re: New air intake

Posted: Tue May 21, 2013 8:01 am
by kimokalihi
There's not much you can do to your intake to better it. It's not really that restrictive either. Are you turbo or NA? If it's turbo you can do the "coffee cup mod" by deleting your resonator box and fabbing up your own replacement piece with all the necessary fittings but I think this is probably more hassle than it's worth. I doubt you'll notice any difference other than it will get louder and therefore may fool you into thinking you gained something.

I think the best thing you can do intake wise, (it's already a cold air intake from the factory) is to remove your airbox and measure the diameter of your intake piping on the engine side of the airbox. Then get a saw or dremel and enlarge the hole that goes into your wheel well behind the fender to the same diameter and also enlarge the hole in the airbox to match and find yourself a pipe of some kind, preferably with a smooth rigid interior and attatch it to the airbox and the wall. This hole is considerably smaller than the intake itself and thus it must be restrictive to some degree. You may also, at this point, remove your silencer box inside the wheel well called the "snorkus delete" which will also make your engine louder up front and add to your feeling of HP gain. Whether it be real or placebo, nobody knows for sure.

The exhaust you could try freeing things up a bit with an aftermarket muffler and an aftermarket high flow cat or cat delete if you want to risk that. You could also put on a larger diameter exhaust pipe but unless you have a turbo this won't do much for you and going too big could have negative effects.

The truth is, and it applies to most cars, intake and exhaust mods don't equate to much. They're often just a waste of money and if not done properly can be detrimental to your performance and certainly your wallet.

Handling is where it's at if you really want to feel some improvements that matter.

Re: New air intake

Posted: Tue May 21, 2013 5:13 pm
by Legacy777
I second Kimo's comments.

Let us know if you have a turbo or non-turbo Legacy and we can maybe provide you with some more specific recommendations.

Re: New air intake

Posted: Wed May 22, 2013 10:51 pm
by Rembly
Its 91 non turbo wagon. After reading that, Ill say it does seem pointless.

Re: New air intake

Posted: Wed May 22, 2013 11:52 pm
by kimokalihi
Indeed. But doesn't mean you should slap some bigger swaybars on and some grippy tires and have some fun in the twisties.

Re: New air intake

Posted: Thu May 23, 2013 12:06 am
by mike-tracy
I assume you mean "shouldn't" right Kimo?

Re: New air intake

Posted: Thu May 23, 2013 12:43 am
by kimokalihi
Yes, you should definitely do some handling mods.

Re: New air intake

Posted: Thu May 23, 2013 1:07 am
by Chrisg03
When i added a Weapon R secret weapon intake i did feel an increase in response and id say about 2-3 mpg increase on long drives

Re: New air intake

Posted: Thu May 23, 2013 1:29 am
by mike-tracy
I'm a cynic. But...2-3% change in mpg is statistically insignificant. You could wear different shoes, lose weight or empty trunk to get the same or better mpg improvement.

The throttle response change makes more sense to me, as having a CAI shifts your power band from down-low to higher in the rev range. You don't make any more (statistically significant) power but it is accessible higher. The tradeoff is in most cases your car is now sucking hot engine bay air. A well designed cai would suck cold air from the fender, but then again a puddle or deep water-filled-pothole could cause you to hydro lock. Like I said I'm a cynic;)

Re: New air intake

Posted: Thu May 23, 2013 5:43 am
by kimokalihi
Chrisg03 wrote:When i added a Weapon R secret weapon intake i did feel an increase in response and id say about 2-3 mpg increase on long drives
Is it a cold air intake or a short ram intake? Like I said before, the stock airbox is a cold air intake. It draws cold air from inside the wheel well so there's no need to put a cold air intake on unless you're doing so to make it flow better by smoothing things out.

Here's an interesting video debunking cold air intakes somewhat. It's not exactly scientifically accurate but I think it serves it's purpose in exposing snakeoil companies such as K&N and WeaponR.

https://www.youtube.com/watch?v=gCi2yo4UqPI

Re: New air intake

Posted: Thu May 23, 2013 8:10 am
by Rembly
This is all very helpful, nice to see both sides.
Would you suggest whiteline sway bars front and back then?

Re: New air intake

Posted: Thu May 23, 2013 9:33 am
by kimokalihi
Yes if they make one for NA. I have a whiteline 20mm rear bar and an 02 WRX Wagon 20mm front. I don't know if these fit the NA cars or not but I'm sure that info is in the suspension sticky thread.

Re: New air intake

Posted: Thu May 23, 2013 5:44 pm
by Legacy777
The rear bar is the same. The front bar is turbo & non-turbo specific.

Re: New air intake

Posted: Fri May 24, 2013 3:57 am
by Chrisg03
LOL its a short ram it revs a bit quicker and the airflow is clearly increased and contrary to popular belief the car is acutally quiter than using the stock airbox but as cynic as you are you are abit off :P our cars average 27 mpg on the highway so a 2-3mpg increase is closer to 10%

Re: New air intake

Posted: Fri May 24, 2013 4:51 am
by kimokalihi
That odd. My car was much louder with a short ram intake than it is now with the factory box.

Re: New air intake

Posted: Fri May 24, 2013 6:49 am
by James614
Chrisg03 wrote:LOL its a short ram it revs a bit quicker and the airflow is clearly increased and contrary to popular belief the car is acutally quiter than using the stock airbox but as cynic as you are you are abit off :P our cars average 27 mpg on the highway so a 2-3mpg increase is closer to 10%
One of the main reasons I got my short ram was for the increased noise. I find your acoustic findings odd.

Re: New air intake

Posted: Fri May 24, 2013 8:08 am
by Chrisg03
Yes it was defiantly odd it clearly makes more engine noise up front but the exhaust note wasnt as throaty

Re: New air intake

Posted: Fri May 24, 2013 8:20 am
by mike-tracy
Chrisg03 wrote:LOL its a short ram it revs a bit quicker and the airflow is clearly increased and contrary to popular belief the car is acutally quiter than using the stock airbox but as cynic as you are you are abit off :P our cars average 27 mpg on the highway so a 2-3mpg increase is closer to 10%
OK I misread 2-3mpg as 2-3%. I still cant believe ingesting hot air would be beneficial on a turbo, but I suppose if were talking long periods of freeway driving then the under hood temps could be a lot cooler than what I was thinking, ie. Stop and go traffic.

Re: New air intake

Posted: Sat May 25, 2013 1:42 am
by randomiam
its not really a study or anything but I thought the few videos those m2m guys did helped shed some light on the different intake setups:

http://www.youtube.com/watch?v=gCi2yo4UqPI
http://www.youtube.com/watch?v=PAIxeQUSg-Q

I don't remember if they tested an NA car but they specifically use a Liberty in one of those videos. They appear counter productive performance wise.. I guess I can see the appeal if they save a bit of space in the engine bay but meh.