[HERR FSTIR]

I have been planning on installing DPs on my 335xi for the last several weeks. Due to my location, it would have to be a DIY job. I studied the BMW TIS and Bentley manual, and acquired necessary tools.

Things went fairly smoothly until the actual removal of the DPs (see below for full description). If anybody has advice on how to get beyond this step, then I can put together a DIY for this project.



As recommended by the BMW TIS and Bentley, I did the following:

1. Removed passenger side axle/CV

2. Removed bearing pedestal

3. Disconnected O2 sensors

4. Unclamped stock DPs at wastegates

5. Unclamped stock DPs from hanger/bracket

6. Unclamped stock DPs from catback



Initially this seemed to provide enough room to negotiate the stock DPs around the subframe. I was trying to remove the front turbo DP (cylinder 1-3) first as the rear turbo DP is totally hidden behind the front DP.

To my total irritation, I could not get the front DP out. I tried pulling the DP straight down (where the bearing pedestal normally would be). I also tried rotating it outwards (where the CV and steering knuckle are normally located).

No matter what I did, the back end of the DP (where it joins with the catback) could not clear the crossmember (that is part of the subframe. This was cut by a member who I think later came to regret it).



At this point there are only four options left:

1. Remove small heat shield attached to the back right corner of subframe. This would be difficult as one of the screws is very difficult to access, and I'm doubtful this will provide enough room to make a difference.

2. Loosen steering rack as is done for installing DPs on RWD models. I don't think this will work since you can't slide the steering rack forward as it would bump into the subframe.

3. Drop subframe about 2 inches. Doable, but a giant PITA.

4. Cut the stock DPs. Don't want to do this since I want the option of reinstalling stock DPs at later date.


Can anybody offer any help or suggestions?

[alextremo]

Had mine done at a shop, I believe they dropped the subframe.

[HERR FSTIR]

The more I think about it, the more I am convinced that dropping the subframe 1-2 inches would be easiest (after removing bearing pedestal). That would have given me enough clearance to get the front DP out.

Unfortunately, I had not considered that option before starting (since the TIS doesn't indicate it's necessary) and wasn't really prepared to drop the subframe.

But I did figure out a few things about the CV joints, seals, and differential. Replacing the CVs would be fairly straightforward. Anyone interested can feel free to send me a pm.

[scooby9]

How did the install finish up? Which DP's did you pick up?

I was thinking of doing the install but using a sawsall to cut the stock DPs and just slide the catless DP's in without doing the whole axle thing.

[itsbrokeagain]

Dropping the subframe is the easiest way to go. Routine xi installs usually take 2.5 hours.

It's really not as hard as everyone thinks. Just need some extra shop tools and a lift.

[HERR FSTIR]

Originally Posted by Matt@Camber-Toe

Dropping the subframe is the easiest way to go.

Yeah, I think on my next attempt I will start by dropping the subframe, and see if that gets me enough room to remove the stock pipes without touching the axle.

Pulling the CV and bearing pedestal made it easier to access to the DPs and O2 sensors, but it would be nice to avoid that altogether.

Any tips on dropping the subframe would be appreciated. Doesn't look very complicated: slightly elevate engine with cherry picker to unload subframe, pull the six fasteners and lower it down on jacks.

The TIS indicates the steering column needs to be disconnected from the rack, but I'm hoping there is enough play in it to avoid doing so.

[HERR FSTIR]

Originally Posted by scooby9

How did the install finish up? Which DP's did you pick up?

I was thinking of doing the install but using a sawsall to cut the stock DPs and just slide the catless DP's in without doing the whole axle thing.

I will give it another shot in a couple weeks when I get a free weekend. I am trying to install VK DPs.

If I can get the stock DPs out by only dropping the subframe without pulling the CV, then it will save a lot of time and hassle. This approach may be straightforward enough to try instead of cutting the OEM pipes.

Let me know if you have any questions. I will put together a DIY after completing the install.

[itsbrokeagain]

Originally Posted by HERR FSTIR

Yeah, I think on my next attempt I will start by dropping the subframe, and see if that gets me enough room to remove the stock pipes without touching the axle.

Pulling the CV and bearing pedestal made it easier to access to the DPs and O2 sensors, but it would be nice to avoid that altogether.

Any tips on dropping the subframe would be appreciated. Doesn't look very complicated: slightly elevate engine with cherry picker to unload subframe, pull the six fasteners and lower it down on jacks.

The TIS indicates the steering column needs to be disconnected from the rack, but I'm hoping there is enough play in it to avoid doing so.

You don't need to disconnect the rack. Unbolt the engine mounts from the bottom and the subframe will hang there supported by the suspension. Put a Jack under each side of the subframe, pull the 6 bolts and then slowly lower the subframe. Then unbolt the passenger side engine mount completely. No pulling axles or bearings or any of that stuff.

This is usually the easiest way to do it. It will take another person to assist you in this.

Where are you located?

[HERR FSTIR]

Originally Posted by Matt@Camber-Toe

It will take another person to assist you in this.

Where are you located?

I've got a buddy who is a skilled mechanic. He helped with the first attempt, and I will undoubtedly get his help for attempt #2. Thanks for your input.

[mattsfeir]

Originally Posted by Matt@Camber-Toe

You don't need to disconnect the rack. Unbolt the engine mounts from the bottom and the subframe will hang there supported by the suspension. Put a Jack under each side of the subframe, pull the 6 bolts and then slowly lower the subframe. Then unbolt the passenger side engine mount completely. No pulling axles or bearings or any of that stuff.

This is usually the easiest way to do it. It will take another person to assist you in this.

Where are you located?

Thanks for this info, I installed a set of AR downpipes on my xi today using the method above. Accomplished solo in my garage with 2 jacks and a set of jackstands. Definitely challenging for a shadetree mechanic, but doable.

[NiVeDh]

Do you have to get an alignment afterwards if you drop the subframe?

[mattsfeir]

Good question, I don't think so as the subframe goes back to the exact same spot and the usual alignment adjustment spots were untouched.

[kdiggz]

Originally Posted by mattsfeir

Thanks for this info, I installed a set of AR downpipes on my xi today using the method above. Accomplished solo in my garage with 2 jacks and a set of jackstands. Definitely challenging for a shadetree mechanic, but doable.

going to give this a shot soon. so how doable is this in your garage by yourself with 2 jacks and some jack stands? is this like a whole day thing or what? any tips? should i just cut the dp's off? haha

[mattsfeir]

It's doable if you're patient. You'll get the O2's out and factory downpipes completely disconnected, then have to drop the subframe to squeeze them out towards the back of the car between the subframe and unibody.

Even when the subframe is hanging by the suspension, I still didn't have enough room, so had to pry the subframe down even further to slide the factory downpipes out and new downpipes in.

Took me the better part of a day since it was my first time and I also put in an intercooler.

Cutting isn't necessary or recommended, but if you do, you'll still have to drop the subframe to get the new downpipes in place.

[kdiggz]

good info, thanks. did you have to unbolt the engine from the motor mounts and jack it up to give yourself more room? or just drop the subframe?

[itsbrokeagain]

Originally Posted by kdiggz

good info, thanks. did you have to unbolt the engine from the motor mounts and jack it up to give yourself more room? or just drop the subframe?

if you do not have access to an upper engine support brace or a hoist to hold the engine, you will need to put a jack under the engine to hold it in place. I usually dont move the engine at all..on the lift i use a block of wood and a pole jack to keep the engine from moving, and use the other pole jack to raise/lower the subframe...makes it easier to line up.

Replace the pole jacks with actual pump jacks, and you can accomplish the same thing.

I can usually get them in and out in 2 hours, provided they actually fit right.

[ChrisB41]

Originally Posted by Matt@Camber-Toe

if you do not have access to an upper engine support brace or a hoist to hold the engine, you will need to put a jack under the engine to hold it in place. I usually dont move the engine at all..on the lift i use a block of wood and a pole jack to keep the engine from moving, and use the other pole jack to raise/lower the subframe...makes it easier to line up.

Replace the pole jacks with actual pump jacks, and you can accomplish the same thing.

I can usually get them in and out in 2 hours, provided they actually fit right.

This is how I did it, with a pole jack and lower the subframe. Took 1.5hrs from start to finish.

[kdiggz]

Originally Posted by ChrisB41

This is how I did it, with a pole jack and lower the subframe. Took 1.5hrs from start to finish.

wow that's not bad at all. ok, i'm feeling better about this now

[erikj7]

Originally Posted by Matt@Camber-Toe

Dropping the subframe is the easiest way to go. Routine xi installs usually take 2.5 hours.

It's really not as hard as everyone thinks. Just need some extra shop tools and a lift.

Thank you!! This was very helpful

[itsbrokeagain]

Originally Posted by kdiggz

i can't find anyone locally to do mine. they all want to charge by the hour and won't commit to a fixed amount. i've had issues with this in the past where they estimate 3 hours and charge for 10. "oops it was more difficult than we thought." i wish there were more options around here

Might just have to make a trip to nyc this weekend

[j2m]

Just got my Vishnu Kittyless DP. I am having it installed next week. Robert sent me instructions on the install for the N55. I thought I would post it up and hope it may help others.

[nailer335]

Good information here. So my CL DPs have been taunting me long enough, time to get them on. After reading this I feel more confident about install information/tips/duration/etc. but aside from the above post, is there anything I should know post install with respect to codes and whatever else?