[Papster1]

Hi, has anyone done a retro fit to their standard air box to create a copy of the M Performance as pictured?
Also if so have you created a modified duct to get cold air to it without sealing it?

Thanks

[Russbmw]

You will want to duct it, unless you simply want more noise and a drop in power - as it will be sucking in hot air from the engine bay without a duct.

[johnung]

Originally Posted by Papster1

Hi, has anyone done a retro fit to their standard air box to create a copy of the M Performance as pictured?
Also if so have you created a modified duct to get cold air to it without sealing it?

Thanks

Modifying the stock F3x N55 airbox like the M Performance Intake is pretty simple to do. Stay in the same area that you see in the MPI photo with the red plastic outline. That piece is supplying support to the hole. So when you cut yours, leave the vertical lines in the plastic for support as in the attached photos.

Absolutely no ductwork is needed. The MPI doesn't add ductwork! The extra hole is in front of the box in the stream of incoming air from the front grille.

The added hole will provide more sound and more air, but you won't get a bump in performance unless you swap the restrictive stock airfilter for a better flowing drop-in filter like the aFe Pro Dry air filter. See photo for part number. It's washable and reusable. Soak 2-3x a year in warm soapy dish detergent water, rinse and let air dry. Save your original filter to pop in during washing/drying.

I've seen all kinds of mod jobs from just drilling big holes to really clean cuts. It's down low in the engine bay and not really visible so being a craftsman isn't necessary. Just be sure to stay within the area that you see for the red outline in the MP Intake photos.

[johnung]

Originally Posted by Papster1

Hi, has anyone done a retro fit to their standard air box to create a copy of the M Performance as pictured?
Also if so have you created a modified duct to get cold air to it without sealing it?

Thanks

Here are some additional photos that may help.

[frchdragon]

Originally Posted by Russbmw

You will want to duct it, unless you simply want more noise and a drop in power - as it will be sucking in hot air from the engine bay without a duct.

The idea is to simulate the same opening as the MPPK air box, nothing else changes. You get the exact same results: More noise.
There is no ducting needed, you get the air from behind the headlight, the rest of the box doesn't change.

[johnung]

Originally Posted by Papster1

Hi, has anyone done a retro fit to their standard air box to create a copy of the M Performance as pictured?
Also if so have you created a modified duct to get cold air to it without sealing it?

Thanks

Some comments about intakes because there is a lot of misinformation circulating...

An intake mod like this home M Performance Intake mid is really nice because cutting the extra hole and adding an $85 drop-in filter adds a nice bump in performance and sound.

I would caution that an intake mod does not add a lot of performance. If it added 15hp, and that is a very big IF, that is only a 5% increase on a stock 300hp engine. And most intakes don't come close to adding that much.

It is a fallacy that an intake is adding a lot more air to the N55 engine. That's physically impossible. An intake opening could be the size of a watermelon and it wouldn't add any more air to the engine. That's because the intake feeds down to the Turbo Inlet Pipe that is less than 2" in diameter feeding air into the turbo housing.

So what the bigger air holes in an aftermarket intake like the BMW M Performance Intake are really doing is not letting more air in so much as letting more engine/turbo sound out!

If there is a small performance bump from an intake it is actually being created by the freer flowing air filter that comes with the intake. It's less restrictive so it allows air to flow through faster. It may only be 2%-3% more, but I think it's noticeable.

Many aftermarket intakes are poorly designed, even if they look pretty and sound good. If they alter the environment around the MAF sensor in the pipe immediately after the airbox, then the engine can run less efficiently and even cause a Check Engine Light on the dashboard.

If the MP Intake/drop-in filter mod isn't enough for you, IMO the MST is a great combination of performance and sound. Below is a video and link.

https://www.kiesmotorsports.com/coll...-system?aff=22

Hope this helps!

[frchdragon]

Filtration is also an issue.
OEM type filters filter better than Oil or dry filters.
Like everything else, it is a compromise.

[Papster1]

Many thanks for your replies.

I had the K&N typhoon kit on my old 335i GT and sounded great however it did whistle when on full throttle and I was never able to find where it was coming from.

So I know the existing air box is fine, and BMW created a box with no ducting with a big hole in it so I thought how hard could it be for the same results as OEM at a fraction of the price???? well clearly very easy judging by the replies.

BMW wouldnt fit a modified box without extensive testing so happy for holes to be cut but then I like it neat so I may buy it from the stealers for a standard fit. I'll see what the costs are or buy a second hand one to mod.

I saw the MST and only slightly cheaper that the K&N and agree I do prefer the non oiled filter.

Cheers for this

[Papster1]

Just got off the phone to BMW and the OEM MPI is £167, eBay second hand lower box £50 and to cut holes is free.....hmmmmmmm

I actually think round holes would be far better IMO and neater.

[johnung]

Originally Posted by Papster1

Just got off the phone to BMW and the OEM MPI is £167, eBay second hand lower box £50 and to cut holes is free.....hmmmmmmm

I actually think round holes would be far better IMO and neater.

Round holes will mean less flow so less sound compared to the M Performance Intake. I personally think rectangular cuts between the vertical supports in the plastic are cleaner. Photo is of someone who drilled holes. Either way it's too low for anyone to see with the hood open.

[Papster1]

Ok, time to make my decision now so will take a closer look. Thanks again 👍

[Papster1]

Just spotted this on an M2 N55, looks like BMW just cut the shape out and never bothered leaving the strengthening bars, well so to speak.

[frchdragon]

Originally Posted by Papster1

Just spotted this on an M2 N55, looks like BMW just cut the shape out and never bothered leaving the strengthening bars, well so to speak.

Looks like a different mold to me, the strengthening bars ends perfectly before the start of the hole.

No matter what, cutting in our original airbox will do the exact same thing and it is not visible how badly you cut it.
I think I will source one at the junkyard and drill into it to see if I like the extra sound, If I don't, I can use my original box.

[Papster1]

That's what I was thinking 👍

[johnung]

Originally Posted by Papster1

Just spotted this on an M2 N55, looks like BMW just cut the shape out and never bothered leaving the strengthening bars, well so to speak.

Maybe that photo is an M Performance Intake with the red plastic outline piece removed.

[Papster1]

Fair point on that, I suppose another symptom of extra air will be a shorter life of the filter fitted...

[KingPP]

Hey guys, someone actually cutted it like the m2 airbox? Without the supporting bars? Guess the plastic is strong enough to not bend

[richsvo]

In my experience, doing the mod listed above will result in CEL without coding. Coding can't be done because of the serialization by BMW for MPPK. Unless someone knows another way?

I tried this on my car (tuned) and got a CEL.

[lovnblack]

Originally Posted by johnung

Here are some additional photos that may help.

Hey John, old threat but I just found it, I want to ask a few questions to you, sent PM, can you plz check it