Removing the milk jug, did it effect your MPG??

Hi guys,

 

I looking into removing the milk jug underneath the air filter and replacing it with HKS funnel. The question I have is for my fellow Legacy(2.5, 3.6 and GT) owners that have removed the milk jug, did they notice any difference in MPG good or bad.

 

I did do a search with "milk jug" and found a few threads that are 1-2 years old on similar. So it's 2014, looking for some new input from users that have done this mod and look forward to them posting their experiences.

 

Thanks, JT

Removing it may impact the flow by the MAF and subsequently "trick" the ECM to adjust or mis-adjust the fuel mixture. At best it's harmless, at worst it can cause you burnt valves.

 

I'd rather spend money on a tune.

Thanks. The tentative was plan is to get the HKS funnel + AEM filter(purchased already) and then get it tuned. Worse case, I'll just use the AEM minus the funnel.

That's the setup I have JT_36R. 45K miles on the ODO, maybe 20K with the funnel + AEM dryflow filter. 10K since tune. 0 issues.

 

Like Fredrik mentioned, you get a slightly lower IAT (intake air temp) hitting the filter and feeding through the manifold with the HKS funnel. MPGs were not affected (within the margin of error up or down, depending on weather and traffic cycle). The tune smoothed out any MAF reading deviations (although ehsnils does have a valid point - there are horror threads on other Subaru forums - NA engines + milkjug delete). In some cases due to the specific intake and exhaust vibrations of H4 and H6 engines, these resonation chambers are needed to prevent turbulance and resonance messing with sensor operation/readings.

 

You'll notice NA Leggies (2.5i, 3.6R) have at least 2 such resonance chambers in the stock intake setup.

 

1. milkjug chamber below the air box

2. smaller chamber near the intake track right before the throttle

 

The boxes not only help with preventing intake resonance that would throw off the MAF readings (low RPMs)

but also to smooth out the airflow and help scavenging on the intake side.

 

Less of an issue on an LGT, more on a 2.5i and 3.6R.

 

With an aftermarket exhaust, especially on an H6, there is usually a need for a similar resonator (helmholtz chamber, j-pipe, test-pipe) to combat drone at certain RPMs.

 

Now, coming back to the HKS funnel, I have not see any adverse effects from installing it in place of the milkjug.

With or without tune (we have plenty of guys running it without a tune).

 

Part of the reason behind this is likely because its not the same as just removing the milkjug and leaving a hole (or plugging it up).

 

I say go for it and if you can, log your MAF readings before/after.

I wonder if you'll see exaggerated readings between 1-2.5K RPM post install.

If you do, a tune would be ideal to calibrate those out.

^^I don't think the GT has 2 intake resonance chambers, just the milk jug.....well, unless you consider the TMIC a resonance chamber.

 

I did the "milking silencer" delete at about 8k miles with no effect on gas mileage. I just took it off, no plug, no funnel. I'm at 28k now with the AEM filter as well and I can hear my turbo spool better now. No issues whatsoever.

^^I don't think the GT has 2 intake resonance chambers, just the milk jug.....well, unless you consider the TMIC a resonance chamber.

 

It effectively doubles as one too. However, it may not be 'tuned' properly. However, that milk jug is likely not 'tuned' properly either. They probably just went for a minimum required volume that would fit in that space, where if they could make it bigger...no harm no foul...

^^I don't think the GT has 2 intake resonance chambers, just the milk jug.....well, unless you consider the TMIC a resonance chamber. I did the "milking silencer" delete at about 8k miles with no effect on gas mileage. I just took it off, no plug, no funnel. I'm at 28k now with the AEM filter as well and I can hear my turbo spool better now. No issues whatsoever.

Its a church pipe organ resonator! Seriously though, I haven't consulted the vacation pics and don't have a 5th gen LGT handy (boo) but doesn't your intake tube leading away from the airbox have any kind of chambers or strange flanges on it? If no, then I stand corrected. The 2.5i and 3.6R ones have some extra chambers near the firewall, where the intake tubing bends to mate up with the intake manifold. Can't really remove them but the Takeda aFe intake tubing does away with them.

http://legacygt.com/forums/showthread.php/samco-intake-and-coolant-lines-210144.html?p=4670064

 

Just a couple accordian sections that lead directly into the turbo compressor. The intake tube goes from the airbox toward the passenger fender then down and passes under the airbox and thru the frame rail to the low mount front turbo.

Zero issues. Zero MPG impact. Zero MAF misread. Improved throttle response.

 

The only reason your mpg is gonna suffer is because you are going to develop a heavy right foot.

 

You have only $150 to lose and 6.5 whp and 9wtq to gain. At a minimum you will see 5whp and 5wtq.

 

If I could just get 5whp and 5wtq for every $150 spent, I would be in heaven! Especially on an NA motor.

 

You're standing at the edge of the pool contemplating. I'm the guy that just pushes you in

You're standing at the edge of the pool contemplating. I'm the guy that just pushes you in

 

We need you to jump in too

Hi guys,

 

I looking into removing the milk jug underneath the air filter and replacing it with HKS funnel. The question I have is for my fellow Legacy(2.5, 3.6 and GT) owners that have removed the milk jug, did they notice any difference in MPG good or bad.

 

I did do a search with "milk jug" and found a few threads that are 1-2 years old on similar. So it's 2014, looking for some new input from users that have done this mod and look forward to them posting their experiences.

 

Thanks, JT

 

 

I have a 2010 and just removed the jug...one week later after full tank same route same mpg...my car sounds cooler though!

 

 

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We need you to jump in too

 

I'm in. Just waiting for the Takeda piece to become available so I can jump in that pool as well

Keep in mind that I am currently working with KSTech to develop an airbox and intake for the GT and hopefully as his development progresses there will be an option for the 2.5 and 3.6R as well.

I had the HKS funnel put in while my car was in the body shop, so I couldn't really do a proper before and after comparison, especially since it was two months in between and the weather turned colder. One thing that definitely sounds different to me is the sound the car makes when it starts up. But that could also be a result of the accident or just from the car sitting there for that long.

I'm trying to find where I can purchase this his funnel I've looked on eBay and amazon and I'm coming up with just filters looked on Google and the one place is sold out and won't be getting any in if you could help me out and point me to the right place is appreciate it thanks

I'm trying to find where I can purchase this his funnel I've looked on eBay and amazon and I'm coming up with just filters looked on Google and the one place is sold out and won't be getting any in if you could help me out and point me to the right place is appreciate it thanks

 

 

I'm not sure if it works for your '09, but you should look into it.

 

Did you try these guys:

http://www.upscaleautomotive.com/import/subaru/wrx-sti/08-gr/intake/p-47885-hks-factory-airbox-air-intake-funnel-for-08-subaru-sti

 

I'm not sure if it works for your '09, but you should look into it.

 

Did you try these guys:

http://www.upscaleautomotive.com/import/subaru/wrx-sti/08-gr/intake/p-47885-hks-factory-airbox-air-intake-funnel-for-08-subaru-sti

Ok so what do these actually do? From what I read and father on here that it pretty much just helps throttle resp once and gives it a little more of a boxer sound??

Ok so what do these actually do? From what I read and father on here that it pretty much just helps throttle resp once and gives it a little more of a boxer sound??

 

 

What have you read? Please post a link, I'm really curious now.

 

Here is something worth reading.

 

http://legacygt.com/forums/showthread.php/2013-legacy-3-6r-intake-dyno-218087.html

 

What have you read? Please post a link, I'm really curious now.

 

Here is something worth reading.

 

http://legacygt.com/forums/showthread.php/2013-legacy-3-6r-intake-dyno-218087.html

just what was in this forum post

Keep in mind that I am currently working with KSTech to develop an airbox and intake for the GT and hopefully as his development progresses there will be an option for the 2.5 and 3.6R as well.

 

Just getting ready to order an AEM drop in and the Funnel...thought I'd check and see if you had any luck with KSTech!

I sent them a bunch of pics of the GT stock intake in December 2013. Emailed him about status in late January as he was planning to have me visit their shop for a test fit the last weekend of January.....and I never heard anything.

Bummer! Well, "A" for effort on your part. It's pretty awesome that you're always trying to help fellow owners, kudos good sir.

What is the consensus on the Milk jug delete? Does it improve performance on GTs or just NA cars. Also, will I need a tune. thanks in advance.

^^^ Answered my own question (or it was answered previously, I just found it)

 

http://legacygt.com/forums/showthread.php/5th-gen-gt-turbo-intake-bov-too-quiet-242622.html?p=5182831&highlight=pre-MAF+avoid#post5182831

I have been running my 3.6R with the jug deleted and a funnel replacement since the car was new....neat intake sound...no issues..... slightly better throttle response..... Mileage??? Not sure all around but it is really good on extended hwy trips.