45 degree airbox or "cone" filter for the Link

Post by **Legacy777** » Thu Jul 24, 2008 2:55 am

I'd like some thoughts on the issue. We've discussed/debated the stock airbox vs. the cone filter before with the stock setup using the MAF for air measurement. What about for a MAP based car. I don't think the turbulance issue is that big of a deal. However I'm not sure if there are other issues associated with the MAP based system that would benefit from the stock airbox vs. a cone filter.

I prefer the 45 degree airbox because it still looks kind of stock and pulls colder air from the fender vs. the engine bay.

The benefit of the cone filter is predominently more air flow.

If I were to do the 45 degree airbox I would move the velocity stack over from the stock air box, modify the bottom of the airbox so it keeps my additional intake tube to increase airflow. I would need to have a pipe fabbed up with a tube so it can feed the IAC valve.

I will probably swap over to the two port charcoal canister and put a check valve in the line so I can do away with the aux. purge. I also believe with the MAP based setup I can bleed the wastegate solenoid back to atmosphere. There may be a slight advantage to venting it back to negative pressure (vacuum) vs. atmosphere....but I'm not sure it's worth the extra headache in adding a fitting.

For those that haven't seen the 45 degree airbox. Here's Jeff's setup.

http://bbs.legacycentral.org/viewtopic. ... city+stack

Thoughts/comments?

jefferson · Post by **jefferson** » Thu Jul 24, 2008 3:17 am

I am all for high flow cold air, hence my setup. I really like the flow potential with the pod setup, but hate the idea of higher than ideal intake air temps.

Autospeed got substantially cooler intake air temps by removeing the snorkel, opening up the intake on the stock box, and getting rid of the resonator.

I have been keeping an eye out for tha Volvo intake piece that I used to open up the intake to the airbox, but I have never seen another one on my many trips to the several pick and pulls in the area. I really wish I had paid attention to what year and model Volvo I pulled it off of. It makes opening up the intake so simple and I seriously doubt you would even need to mess with the bottom of the box. If and when I come across another one I am for sure going to grab it for someone else that needs to mod their box.

I also feel that with the improvement the mods did for the stock turbo, if you are running a modded turbo it would make an even larger improvement. I would almost bet you are kind of choked off with yours and will really love the free breathing afterwards.

Jeff

jefferson · Post by **jefferson** » Thu Jul 24, 2008 3:44 am

I just thought of something else that would be pretty neat that they have for the Audi S4 I have, and you would probably be the one to work this out. AWE has an s-flow for the Audi that involves a pod filter inside the stock airbox. The best of both worlds. It would involve an angled adapter to do, but I think our airbox is big enough.

Jeff

Post by **Legacy777** » Thu Jul 24, 2008 3:56 am

Jeff,

I never saw the piece you're talking about from the Volvo? Any pictures?

I have opened up my stock air box and added an additional intake tube, so I would assume it's flowing better then the stock setup...but who's to say for sure.

jefferson · Post by **jefferson** » Thu Jul 24, 2008 4:38 am

I don't have any pictures. You have seen my attempts with pictures and the internet. I only used a few inches of the piece off the Volvo, just enough to flair one end and get into the box. If I ever find another one I will take a picture and send it to you. I have figrued out the email picture thing, except for the size.

Jeff

Post by **Legacy777** » Thu Jul 24, 2008 2:46 pm

If you have any other pictures then what you already sent me, please send them over. I'll through them on my server.

93forestpearl · Post by **93forestpearl** » Thu Jul 24, 2008 4:39 pm

I've been running speed density for over a year and a half with my G2, and wouldn't have it any other way. It is a little more work on the tuning end with getting your air compensations dialed in, and you do that when different temps come around. Its not hard if you have a wideband, which you do.

Personally, I like the flexibility of speed density as far as your intake plumbing goes. You don't even have to have an intake if you don't want to. Also, venting the BOV to atmosphere makes life easier and the engine bay cleaner, and besides, TiAL > all.

My shorty intake is a pure function of a lack of time and proximity to a welder. I'm going to get some 3" aluminum bends and tubing to move the filter down to where the intake silencer was, its just a matter of having the time. I do suck in some pretty hot air from the engine bay at times.

The other perk to speed density is if you pop a coupler off of your piping the car will still drive, as opposed to mass-air systems being crippled.

Post by **Legacy777** » Thu Jul 24, 2008 5:02 pm

Thanks for the comments Dan.

Post by **Legacy777** » Sat Aug 02, 2008 3:53 am

Any more comments?

93forestpearl · Post by **93forestpearl** » Mon Aug 04, 2008 4:21 pm

I suppose if you are keeping the stock turbo for a while it would be easier to run an intake setup similar to that. Running speed-density vs. mass-air is your call. A mass air system will be easier to tune off the bat, as speed density requires you to adjust your air temp compensation table when those temps arise.

I like the flexibility of speed-density, but it is more work.

Post by **Legacy777** » Mon Aug 04, 2008 6:14 pm

I've got the turbo I plan to use in there now.....and understand the issues with speed density once you go and change stuff....which is why I'd like to get it figured out....

kamr0n · Post by **kamr0n** » Thu Aug 07, 2008 2:57 am

imo stock air boxes are fine. just throw in an ams oil filter...

http://www.amsoil.com/catalog.aspx?code=EAA74-EA.

most cones ie k&n are crap for filtration.

93forestpearl · Post by **93forestpearl** » Thu Aug 07, 2008 5:12 am

My compressor wheel looks just fine after a year and a half. $20 cone filters ftw. I have a few friends who run zero filter.

A1Fiddler · Post by **A1Fiddler** » Fri Aug 08, 2008 6:57 pm

So does nobody have pictures of this volvo piece? Where can I pick up this 45* airbox as well?

jefferson · Post by **jefferson** » Fri Aug 08, 2008 8:36 pm

The airbox is off the 2nd gen. Legacy and possibly Impreza too. The top clips on rather than bolts down as ours does. The only interference is the mounting bracket for the boost controller etc. It gets in the way of the rear clip. I just moved the assembly over and it is held on with one bolt now.

The Volvo piece isn't critical. It just made it very easy to enlarge the intake tube into the airbox. I cut up the Volvo tube and just used the straight piece of tube as it was just the right size to fit tight in the hole in the airbox. I drilled out the rivets on the plate that holds the rubber seal around the tube and removed it. The piece of tube I used off the Volvo fit that much larger hole snugly after a little sanding to make the hole slightly larger .I then used some weatherstrip foam with the sticky back to use as a seal around the tube on the fender side. Aluminum tape holds everything in place from the inner fender side. I bellmouthed the end of the tube that sticks into the fender by useing heat and a metal funnel. Worked great. Alot more area to flow air.

Jeff

92 ra-r · Post by **92 ra-r** » Mon Aug 11, 2008 3:52 am

I just got done doing this mod. It makes a pretty big difference. I'd love to share my swap info as well. How do I post pictures?

Post by **Legacy777** » Mon Aug 11, 2008 5:50 pm

You need a hosting provider/server for the pictures.

If you email them to me, I can host them.

Post by **Legacy777** » Sun Aug 17, 2008 6:27 pm

I did some testing fitting of the 45 deg airbox. My Impreza has this airbox, so I stole it for a test fitting.

I think it will work in the Legacy. The tube connecting to the turbo 90 deg hose will probably need to be fabricated. I'm not sure if I can buy anything that will piece together.

Here's pictures
http://www.main.experiencetherave.com/s ... irboxtest/

Here's some pertinent specs

- There's about 1/2" rise from the airbox to the 90 deg hose on the turbo intake

- The angle from the turbo intake to the airbox is about 55 degrees.

- Straight line distance from the airbox opening to the 90 degree turbo intake hose is aproximately 8.5"

- 90 degree turbo inlet receiving diameter is about 2.55". Probably need piping with 2.5" OD

- MAF adapater dia is aproximately 3.172"

- IAC hose fitting is aproximately 0.782". Would need 3/4" hose.

jefferson · Post by **jefferson** » Mon Aug 18, 2008 4:32 am

I am pretty sure that raceparts.com has the parts you need. You will need a 3" to 2 1/2" adapter and a 45 degree elbow in aluminum. You won't find anything for 55 degrees and the 45 works fine. Then you will need the tubing for the iac line and some bungs for the screw in nipples for the other lines. The bungs were much deeper than need be so I ended up having to grind quite a bit off the inside to smooth everything up. They must have protruded at least 1/4 to 3/8 of an inch inside the tube.

The one thing I would do differently would be the end that goes into the 90 degree rubber elbow. It needs to be larger to fit right and we were thinking expanding that end to fit. It could be better and I think I figured out a better way. You should have some left over straight pipe that you took the elbow out of. Cut about an inch length of that and then split it and open it up to fit over the 90 degree elbow end of the 45. Weld it on and fill in the gap with weld and I think you will have the right od size for the inside of the 90. You will also have a double thickness of metal there for strength. Much cleaner than the way I did it.

Jeff

Post by **Legacy777** » Mon Aug 18, 2008 2:36 pm

Thanks for the feedback Jeff.

Post by **Legacy777** » Wed Sep 03, 2008 5:48 pm

I talked with the shop that is doing the tuning. They said they could fab me up something. The issue they have is the reduction section. It'd be easier to keep it 2.5" all the way, and while the decreased diameter probably won't be that big of a deal, I'd prefer to keep it 3" if possible.

www.siliconeintakes.com has 2.5" to 3.0" reducer & 45 deg bend coupling all in one. I'm leaning towards using it, and a silicone joiner to mate up to 90 deg intake before the turbo. That way I can keep the 3" piping from the airbox to the reducer. Plus it should minimize their work. They'll still need to fab up a line going to the IAC valve hose.

Here's links to the coupler & joiner
Joiner
Coupler

PhyrraM · Post by **PhyrraM** » Fri Sep 05, 2008 6:11 am

Josh, added a pic here that might help you with your figuring.

http://bbs.legacycentral.org/viewtopic. ... 3&start=47

Post by **Legacy777** » Fri Sep 05, 2008 6:26 pm

Thanks for the pics!

It's a shame it doesn't turn a little more. It'd be perfect then.

jefferson · Post by **jefferson** » Thu Sep 25, 2008 8:28 pm

Was wondering how your airbox project was coming along? Any updates?

Jeff

Post by **Legacy777** » Fri Sep 26, 2008 1:55 am

No updates. I haven't really worked on the car for about 2-3 weeks. The hurricane put a stop to last weekend, and I just haven't really been motivated.

I still have been collecting the parts, and think I have mostly everything I need.

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45 degree airbox or "cone" filter for the Link

45 degree airbox or "cone" filter for the Link