M57 - How to fit a N54 intercooler and delete red boost hose

Krazi3azn

Private
Nov 7, 2016
29
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Canada
Here’s a how to delete your red boost pipe and get an intercooler for under $300

Not so much a DIY since it’s a straight forward install. Main reason of doing this is eliminate the leaky red boost hose and also find an alternative better than stock. Yes, there are alternatives out there like ATM which have a plug and play options BUT this will enable you to install any high performance N54 intercooler like the VRSF 7.5" race.

Things you need
1. Intercooler, I bought the cheapest one off aliexpress for testing purposes but more importantly I wanted to delete the red boost hose. You just need a style like below, not the clip connects.

7-FMK8-Front-Mount-Intercooler-Kit-for-BMW-exchanger-N54-N55-135i-335i-intercooler-E82-E88.jpg

2. HPS 90 degree coupler 2.25" to 3" (HTSER90-225-300-BLK), this will need to be cut to fit, will explain further below. You can find your own locally, but this was the only one I found that was long enough with 4" legs (need at least 3")

41Y3peEmAzL.jpg
3. 45 degree coupler 2.75" to 3", I used a performance world 118273 reducer, again longer legs the better, this was 5"
118273-2T.jpg
4. Hanger bolts, nuts, washer, plastic spacer at your local home depot
Hanger-Bolt.jpg_350x350.jpg

Installation Methods
Won't go through how to take out the intercooler but how I managed to get this installed. Basically just gotta remove the intercooler and cut the shroud depending on which one you bought. Lots of these photos were stolen from other DIYs.

Step 1:
Hot side Method 1 (most ideal)
Get an insert from ATM, he does sell these separate if you ask or I could maybe CNC them locally. This would allow you to install the 45 degree coupler easily. Did not have to cut the coupler but thinking back a bit might of help inserting the intercooler.

Screen Shot 2019-11-30 at 10.55.12 AM.png Screen Shot 2019-11-30 at 10.55.02 AM.png

1a. Hot Side Method 2
Cut the red boost hose and clamp the coupler on top. Its a bit tricky since you have to put it back on with the clip.
Screen Shot 2019-11-30 at 10.25.08 AM.png Screen Shot 2019-11-30 at 10.25.14 AM.png

Method 3
Orions way, seems to be the least effective since all they do is shove a coupler in and clamp it
Screen Shot 2019-11-30 at 11.06.19 AM.png


Step 2:
Cut off the cold side intercooler coupler. I used a Dremel and carefully cut the clamps off. Then install the 90" coupler (I had to cut about 2" from the top and 1" from the bottom)
Optimized-20151129_182825.jpg

3. Put in intercooler and install hanger bolts and hardware. As the stock intercooler bolts wont be long enough this is where the hanger bolts come in.
Screen Shot 2019-11-30 at 10.26.48 AM.png

4. Finished product, no more leaks or have to replace any more $$$ orings.
IMG_1965.JPG intercooler.jpg


Hope this helps, in the future I will be helping a friend with his X5D.
 
Last edited:

HobbsyUK

New Member
Mar 5, 2025
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0
I believe it was around $50 usd shipped, you’ll have to email ATM.Will prob upgrade to a vrsf stepped intercooler in the future but this will do for now.
Sorry if you no longer have this setup but I wanted to do the same for my 335D, currently noticeable oil residue on both cold and hot side, the boost hose in place is MTC and I need to replace with my recent purchase:

7.5” intercooler for 335i (as yours is) for a 335d, and the hoses I have are:

1 x 90-Degree Silicone Transition Coupler 2.25" To 3" Mishimoto MMCP-R90-22530BL

1 x Mishimoto 45-Degree Silicone Transition Coupler, 2.75" to 3.00", Black

What size hose clamps did you use? I’ve got 68-73mm which are too small for the intercooler connection and too large for the 2.25” but I have smaller clamps that work for the small connection.

With step 1, is this the same: “
MTC MOTORSPORT BMW 335D ALUMINIUM
INTERCOOLER CONNECTOR BOOST for E92”

Sorry to post on a very old post but I like this setup.

Thank you.