[Infamouscrew02]

Briefly looked around for a DIY to install a Down Pipe on my f10 n55 and didn't come up with much. Saw a bunch for the f30 but not the f10. So I figured I'd make one. Obviously this would be easier with a lift, but I managed just fine doing it on my garage floor with the front end jacked up.

REMOVING THE DOWN PIPE:

Step 1: Pop hood and remove the engine cover.

[img]https://c2.staticflickr.com/9/8350/2...4363a668_c.jpg[/img]

Step 2: Remove sensor on the intake tube.

[img]https://c4.staticflickr.com/9/8624/2...bae723d1_c.jpg[/img]

Step 3: Remove intake.

[img]https://c5.staticflickr.com/9/8260/2...1da3f788_c.jpg[/img]

Step 4: Gain access to the o2 sensor connectors and disconnect.

[img]https://c2.staticflickr.com/9/8284/2...48348b81_c.jpg[/img]

[img]https://c2.staticflickr.com/9/8667/2...75a1219b_c.jpg[/img]

Step 5: Remove body shield to gain access to the down pipe. (A electric impact drill makes this a step go by a lot faster, there are a lot of screws.) Size 8mm

[img]https://c2.staticflickr.com/9/8160/2...06622d46_c.jpg[/img]

Step 6: Loosen up the down pipe and mid pipe band clamp. Size 15mm

[img]https://c7.staticflickr.com/9/8517/2...e23505c6_c.jpg[/img]

Step 7: Remove the two nuts that hold the down pipe brackets in place. Size 13mm

[img]https://c1.staticflickr.com/9/8081/2...f36b951a_c.jpg[/img]

Step 8: Loosen and remove the V-band clamp that connects the down pipe to the turbo. 13mm

[img]https://c2.staticflickr.com/9/8025/2...aa2e597f_c.jpg[/img]

Step 9: At this point you can apply pressure and the down pipe will separate from the turbo housing. You will also need to apply pressure to the mid pipe while wiggling the down pipe to separate the two. (Took some convincing to get them to come apart.) Once they are apart the down pipe will be free and you can slide it out from under the car.

Step 10: Remove the o2 sensors from the stock pipe and install into the new down pipe.

[img]https://c7.staticflickr.com/9/8791/2...dd2c8000_c.jpg[/img]

Here's the difference between the two:

Catted:
[img]https://c7.staticflickr.com/9/8098/2...679f12b2_c.jpg[/img]

Catless:
[img]https://c6.staticflickr.com/9/8196/2...bcc80b0f_c.jpg[/img]

INSTALLING THE ER DOWN PIPE

Step 1: Slide the down pipe and the mid pipe together.

Step 2: Slide the down pipe brackets onto the mounting bolts.

Step 3: Alight and slide the down pipe into the turbo housing.

Step 4: Install and tighten the V-Band clamp onto the down pipe and turbo. This step is important to make sure you get a good seal.

Step 5: Tighten the nuts onto the bolts that hold the down pipe brackets in place.

Step 6: Tighten the mid pipe band clamp.

Step 7: Fish the o2 sensor connectors up into the engine bay and reconnect them.

Step 8: Install the intake and engine cover

Step 9: Start the car and be amazed by the glorious sound.



Tips and trouble that I ran into:
I had a hell of a time getting the ER down pipe into the mid pipe, I had to expand the mid pipe inlet out some so that it would slide in.

When trying to get the down pipe to seat in the turbo, I wanted to blow the damn car up and burn my house down. It was very frustrating. Finally after many tries I pulled the pipe out and compared it to the stock down pipe. Only difference I saw was that on the ER pipe, the holes for the brackets were just barely big enough to go on to the bolts. The holes were much smaller compared to the stock DP. I got the drill out and made the holes bigger and the down pipe slid right onto the turbo.

Also, wear gloves when working on this project. My fingers got all sorts of cut up while working on this.

[Bmw doubles]

Nice write up man!

[mike@x-ph.com]

Very helpful, thank you!!

[lsturbointeg]

Thanks! Will save this for future references. BTW any gas smells? How does it perform?

[Infamouscrew02]

Originally Posted by lsturbointeg

Thanks! Will save this for future references. BTW any gas smells? How does it perform?

I haven't noticed gas smells. I do notice the exhaust fumes are a little more pronounced if you idle for a long time. Nothing smells within the cabin.

Definitely can hear the turbo spool much more pronounced. The boost hits sooner in the RPM range and I can see the values in my p3cars vent gauge climbing quicker.

Love the exhaust note. Seems like some of the drone has been taken from the in cabin as well.

[mike@x-ph.com]

Originally Posted by lsturbointeg

Thanks! Will save this for future references. BTW any gas smells? How does it perform?

Originally Posted by Infamouscrew02

I haven't noticed gas smells. I do notice the exhaust fumes are a little more pronounced if you idle for a long time. Nothing smells within the cabin.

Definitely can hear the turbo spool much more pronounced. The boost hits sooner in the RPM range and I can see the values in my p3cars vent gauge climbing quicker.

Love the exhaust note. Seems like some of the drone has been taken from the in cabin as well.

As with any catless, if you keep the car on idle for a while you will notice gas smell (on the outside of the car only, no smell inside)

99% of the people are fine with it since you rarely have the car on idle for a long time but if you are very sensitive to the smell get the catted option

[lsturbointeg]

Can you describe the tone of your exhaust...did the tone get higher in pitch/tone or just louder if you know what I mean? Or is it more raspy? I know the Meisterschafts I got will be pretty loud especially when they are open but with DP's I was a little bit concerned if it was going to be obnoxious loud

What other performance mods have you done Silver? As soon as I'm done with the exterior mods I'll be working on performance next. The only thing I have but it's sitting in storage is my Meister's but I've been doing enough research that a tune, DP, CP is on my list

[mike@x-ph.com]

Originally Posted by lsturbointeg

Can you describe the tone of your exhaust...did the tone get higher in pitch/tone or just louder if you know what I mean? Or is it more raspy? I know the Meisterschafts I got will be pretty loud especially when they are open but with DP's I was a little bit concerned if it was going to be obnoxious loud

What other performance mods have you done Silver? As soon as I'm done with the exterior mods I'll be working on performance next. The only thing I have but it's sitting in storage is my Meister's but I've been doing enough research that a tune, DP, CP is on my list

Instead of describing, post a video

My advice to you is to do the exhaust first and if you still want more sound get the downpipes.

[izaazk]

Also interested in how it sounds! I have a f10 535i and debating between catless dp or catback

[Infamouscrew02]

I'll work on a video soon.

[Secret_Asian]

n55 catless sounds decent, not too loud no drone but on cold start its noisey

[Bmw doubles]

Originally Posted by Secret_Asian

n55 catless sounds decent, not too loud no drone but on cold start its noisey

Ya need cold start delete

[FSociety]

Originally Posted by Bmw doubles

Ya need cold start delete

Then get a N20 hahaha jk
Let it be, catless is not that loud after a few seconds just the initial start.

[Secret_Asian]

Originally Posted by Bmw doubles

Ya need cold start delete

already have it I figured I'd say that because most people probably dont, much better with cold start delete

[Shnitzer]

Thanks a lot for the detailed instructions on downpipe install , Mustered up the courage to do it in my garage worked out well about 2-3 hrs . I probably would not have done it without a lift if I had not seen your write up thanks again!
this makes a big improvement everything feels better , I still retained factory mufflers car is quiet with a little burble at idle ( Very little) I like it !

[Proimport]

Any check engine light?

[jderek22]

Hello,

I am currently trying to replace my downpipe. I have a question about your install. How were you able to access the nut on the top bracket of the original downpipe?

Thanks,
Jon

[sweettalker]

Anyone in socal area have downpipes? I feel mine is getting too much rasp by the dp area almost like an exhaust leak sound when giving it throttle. My installer says it is on proper,but im not sure. It sounds like when the mating part is not fully tightened on the exhaust piping.
Can anyone in socal help me out and let me hear ur car? Im in la area koreatown midwilshire

[chris_mauck]

Nice work. Just did mine today, took longer than expected. Sounds great other than a small exhaust leak I can't get to seal up.

[ssgm1x]

F10 N55 currently running High Flow Catted DP but that will change tomorrow. Going to gut out the $900 High Flow AR Design Cat so when i take car to BMW at least it looks like i have a Catalytic converter....Lol.
Im just tired of the stock sound and also want some burbles. Also got a "catalytic efficiency below threshold" code after 3 months with my high flow cat so why not gut it now.....nothing to lose at this point.

[John H.]

Originally Posted by sweettalker

Anyone in socal area have downpipes? I feel mine is getting too much rasp by the dp area almost like an exhaust leak sound when giving it throttle. My installer says it is on proper,but im not sure. It sounds like when the mating part is not fully tightened on the exhaust piping.
Can anyone in socal help me out and let me hear ur car? Im in la area koreatown midwilshire

In the very near future, I will be installing a catless DP. I work in 90210, and can stop in K-Town. I'll keep you posted.

[_BSMM5]

How much do you think a garage would charge to install this?