New air intake

Front, Top, Air, Water.

Moderators: Helpinators, Moderators

Post Reply
Rembly
First Gear
Posts: 67
Joined: Thu Apr 25, 2013 4:33 am

New air intake

Post 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?
kimokalihi
Fifth Gear
Posts: 8360
Joined: Mon Nov 06, 2006 3:41 am
Location: Tenino, WA

Re: New air intake

Post 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.
98 Metro Hatch Daily Driver :)
91 SS EJ20G Engine/Tranny/Diff Swap Build Thread Here
"Your testes are close to your bottom but you still play with them all the time." Jeremy Clarkson
Legacy777
Site Admin
Site Admin
Posts: 27884
Joined: Tue Oct 15, 2002 11:37 am
Location: Houston, Tx
Contact:

Re: New air intake

Post 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.
Josh

surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT

If you need to get a hold of me please email me rather then pm
Rembly
First Gear
Posts: 67
Joined: Thu Apr 25, 2013 4:33 am

Re: New air intake

Post by Rembly »

Its 91 non turbo wagon. After reading that, Ill say it does seem pointless.
kimokalihi
Fifth Gear
Posts: 8360
Joined: Mon Nov 06, 2006 3:41 am
Location: Tenino, WA

Re: New air intake

Post 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.
98 Metro Hatch Daily Driver :)
91 SS EJ20G Engine/Tranny/Diff Swap Build Thread Here
"Your testes are close to your bottom but you still play with them all the time." Jeremy Clarkson
mike-tracy
Moderator
Moderator
Posts: 5000
Joined: Tue Aug 25, 2009 7:52 am
Location: Des Moines, Wa

Re: New air intake

Post by mike-tracy »

I assume you mean "shouldn't" right Kimo?
1992 Legacy SS 5mt, build in progress
Josh Colombo wrote: Mon Jan 14, 2002 10:23 am Wait....I'm confused now.
kimokalihi
Fifth Gear
Posts: 8360
Joined: Mon Nov 06, 2006 3:41 am
Location: Tenino, WA

Re: New air intake

Post by kimokalihi »

Yes, you should definitely do some handling mods.
98 Metro Hatch Daily Driver :)
91 SS EJ20G Engine/Tranny/Diff Swap Build Thread Here
"Your testes are close to your bottom but you still play with them all the time." Jeremy Clarkson
Chrisg03
First Gear
Posts: 126
Joined: Wed Dec 14, 2011 11:43 pm
Location: Bakersfield CA
Contact:

Re: New air intake

Post 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
Always open to learn
mike-tracy
Moderator
Moderator
Posts: 5000
Joined: Tue Aug 25, 2009 7:52 am
Location: Des Moines, Wa

Re: New air intake

Post 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;)
1992 Legacy SS 5mt, build in progress
Josh Colombo wrote: Mon Jan 14, 2002 10:23 am Wait....I'm confused now.
kimokalihi
Fifth Gear
Posts: 8360
Joined: Mon Nov 06, 2006 3:41 am
Location: Tenino, WA

Re: New air intake

Post 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
98 Metro Hatch Daily Driver :)
91 SS EJ20G Engine/Tranny/Diff Swap Build Thread Here
"Your testes are close to your bottom but you still play with them all the time." Jeremy Clarkson
Rembly
First Gear
Posts: 67
Joined: Thu Apr 25, 2013 4:33 am

Re: New air intake

Post by Rembly »

This is all very helpful, nice to see both sides.
Would you suggest whiteline sway bars front and back then?
kimokalihi
Fifth Gear
Posts: 8360
Joined: Mon Nov 06, 2006 3:41 am
Location: Tenino, WA

Re: New air intake

Post 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.
98 Metro Hatch Daily Driver :)
91 SS EJ20G Engine/Tranny/Diff Swap Build Thread Here
"Your testes are close to your bottom but you still play with them all the time." Jeremy Clarkson
Legacy777
Site Admin
Site Admin
Posts: 27884
Joined: Tue Oct 15, 2002 11:37 am
Location: Houston, Tx
Contact:

Re: New air intake

Post by Legacy777 »

The rear bar is the same. The front bar is turbo & non-turbo specific.
Josh

surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT

If you need to get a hold of me please email me rather then pm
Chrisg03
First Gear
Posts: 126
Joined: Wed Dec 14, 2011 11:43 pm
Location: Bakersfield CA
Contact:

Re: New air intake

Post 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%
Always open to learn
kimokalihi
Fifth Gear
Posts: 8360
Joined: Mon Nov 06, 2006 3:41 am
Location: Tenino, WA

Re: New air intake

Post by kimokalihi »

That odd. My car was much louder with a short ram intake than it is now with the factory box.
98 Metro Hatch Daily Driver :)
91 SS EJ20G Engine/Tranny/Diff Swap Build Thread Here
"Your testes are close to your bottom but you still play with them all the time." Jeremy Clarkson
James614
Fourth Gear
Posts: 1744
Joined: Sun Jun 10, 2007 4:35 am
Location: Arkansas

Re: New air intake

Post 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.
93 Touring Wagon (EJ20G 5spd Swap) -- Finally back and running strong as ever!

05 Outback 2.5XT 5spd -- Now the wife can have her SUV and get in on the turbo Legacy goodness at the same time.
Chrisg03
First Gear
Posts: 126
Joined: Wed Dec 14, 2011 11:43 pm
Location: Bakersfield CA
Contact:

Re: New air intake

Post by Chrisg03 »

Yes it was defiantly odd it clearly makes more engine noise up front but the exhaust note wasnt as throaty
Always open to learn
mike-tracy
Moderator
Moderator
Posts: 5000
Joined: Tue Aug 25, 2009 7:52 am
Location: Des Moines, Wa

Re: New air intake

Post 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.
1992 Legacy SS 5mt, build in progress
Josh Colombo wrote: Mon Jan 14, 2002 10:23 am Wait....I'm confused now.
randomiam
Second Gear
Posts: 349
Joined: Fri Sep 17, 2010 1:17 am
Location: Auburn, WA

Re: New air intake

Post 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.
Subaru-less
Post Reply