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Discussion Starter · #1 ·
If you want a free Mountune airbox, remove your stock airbox, and cut the bottom out of it. This effectively creates an unlimited plenum intake which draws cold air from underneath/at the front of the car.

Having taken measurements of the Mountune box, the only benefit is having a shiny piece of metal that effectively conducts heat into the intake tract.

I used a dremel, there are other methods. Takes about 10 minutes including airbox removal. Decent gain of sound and 5whp/8lb ft tq on a mustang dyno with the Cobb stage 1 91 tune running 93 octane.
 

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Did you take any photos? I would love to see what/where was cut.
 

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Sounds interesting, can you take some pictures of your DIY?


Sent from my iPad using Tapatalk
 

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Id be very interested in seeing this too, had the same idea when i saw the Mountune airbox but not yet game to start chopping.
 

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Good idea here.
The only thing is my paranoia around dealer warranty. That's another advantage of an after market part is that I can 'stock out' when I go in for a service.
 

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Discussion Starter · #13 ·
Good idea here.
The only thing is my paranoia around dealer warranty. That's another advantage of an after market part is that I can 'stock out' when I go in for a service.
They wont notice... its not readily visible.
 

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Hmm, not bad, so its just pretty much a hole at the bottom of the airbox without the Mountune hose thingy right?
 

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Discussion Starter · #15 ·
Hmm, not bad, so its just pretty much a hole at the bottom of the airbox without the Mountune hose thingy right?

The mountune airbox replaces the last 12 inches of the stock airbox with a hose. This hole opens where the hose ends. The idea is to create an unlimited/infinite volume plenum for the intake to draw air while keeping it shielded from engine heat. Being plastic and not metal, the stock airbox is excellent at insulating the air charge, unlike the mountune box.

The restriction in the stock system is in the snorkel. In reality, the stock system has little restriction, but with this mod, throttle response is increased and the airbox can flow without restriction. There is also zero risk of hydrolock as there is a secondary intake pathway from the stock snorkel
 

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The mountune airbox replaces the last 12 inches of the stock airbox with a hose. This hole opens where the hose ends. The idea is to create an unlimited/infinite volume plenum for the intake to draw air while keeping it shielded from engine heat. Being plastic and not metal, the stock airbox is excellent at insulating the air charge, unlike the mountune box.

The restriction in the stock system is in the snorkel. In reality, the stock system has little restriction, but with this mod, throttle response is increased and the airbox can flow without restriction. There is also zero risk of hydrolock as there is a secondary intake pathway from the stock snorkel
Nice, I see that you quoted a pretty nice HP/TQ gain, do you have the dyno charts? thanks
 

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It's a little rough, lol.

I might do this but cut out the bottom and add in a duct more cleanly, also check the stock intact tract for any restrictions pre-turbo
 

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Discussion Starter · #19 ·
It's a little rough, lol.

I might do this but cut out the bottom and add in a duct more cleanly, also check the stock intact tract for any restrictions pre-turbo

Well, I did it 10 minutes before I left the shop for a St. Patricks Day party, dyno'd before and after, same day, same conditions. There is without a doubt restrictions pre turbo in the intake tract.

I am waiting on an email from the dyno.

I plan on sanding it down eventually ( maybe on the next oil change).... but that is a BIIIG Maybe as no one sees this and it serves its purpose
 
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