hatterasman

I’d have to go a 3 or 4. I did not consider this difficult. It is working in a tight space. I think a decent 3/8” drive flex head ratchet, a universal joint, and a couple of different extensions are needed to reach the bolts for the v-bands.

A set up E-torx sockets (reverse torx) are needed for the exhaust mounting bracket and 2 transmission bolts holding the cat bracket. (The cat bracket is not needed and must be removed.)

I watched a YouTube video for a 335 and read a couple of 335 DIY’s. I did not find a 535xi write up, other than a few comments that it is harder on the x drive. Bentley says to remove the right side axle bearing block on the x-drive. YouTube video shows dropping the steering rack. One write up even mentioned dropping the sub frame. None of this was necessary. Needless to say, I was prepared for this to be a lot more work than it was.

I found getting the O2 sensors out to be the biggest pain. With hindsight, I would probably try to drop the pipes with the sensors in and I would try to fit the new ones with the sensors mounted. I found a 7/8” crow’s foot helpful for reaching the OEM sensor locations. A thin and short 7/8” open end was helpful putting the O2 sensors back. AR sensor locations are different and slightly easier to reach than the original locations.

It’s probably worth mentioning that my car has never seen salt. The exhaust system to down pipe bolts were in perfect shape and came right off. Fighting rusty fasteners could add some work.

The YouTube video from AR is worth watching. The only tricky part is lining the pipes up with the exhaust. The video offers the tip of not tightening the v-bands so the pipes can be rotated slightly to align them perfectly with the flanges. I realized that aligning them is critical, however tightening the exhaust flange bolts before the v-bands pulled the pipes away from the turbos. After I loosened the exhaust flange bolts the v-bands were loose. Once I tightened these up and snugged the pipes up to the turbos, I was no longer perfectly aligned with the exhaust. Tedious, but not terribly difficult.

I found that that the exhaust bracket on the transfer case bolted back in a slightly different place. The exhaust is pulled closer to the front of the car by about a ½”. The AR pipes are slightly shorter than the OEM ones.

Pay attention to O2 sensor location relative to the “front” and “rear” turbo locations the AR pipes are routed differently. I inadvertently crossed the sensors and had to pull them again and swap them.

One other item to note is there is a gasket in a groove in the back of the turbo. I did not replace these and they appeared to be in good shape. The flanges are machined perfectly and are sharp. Use care not to dig into the gasket when inserting the pipe flange.

If you consider yourself a decent mechanic with decent tools, it's a DIY job.

pocholin

It looks great. Reading your experience makes me want to get mine! Congrats!

hatterasman

Two videos for comparison. First is the 535xi with the AR Downpipes, second one is a 335i with stock exhaust.

535xi w/ AR resonated DP's


335i Stock Exhaust


Exhaust sound inside the car is not noticeable. Nice exhaust note at WOT.

chea

was holding out on this mod because people said it was a pain but looks like this will be my next mod. Great write up Thanks for posting

sterile stork

Those two sound so similar, and the down-pipes add such a minimal amount of rasp; awesome! Thank you for sharing. Now I need for the turbos to need replacing so I can lump new units alongside the new downpipes

radarcontact

Man, I guess I'm not a decent mechanic because I spent ALL DAY today just removing the old pipes, nevermind getting the new ones installed. Mine is a 2010, maybe different than the 2008 and my pipes are VRSF not AR. Don't know. One of the hardest things I've ever done mechanically.

ericono

Do the AR or VRSF pipes need modification due to the xdrive?

Thanks,

Eric

hatterasman

The AR pipes I installed were a direct fit. The pipes were slightly short of the exhaust flanges but it was easy enough to pull the exhaust forward slightly.

This is working in tight places and that makes alignment a bit of a PITA, but in the end the fit is perfect. I probably couldn't get two sheets of paper between the block and the closer pipe, but it doesn't touch and that's what counts.

BTW, I'm still loving the change and absolutely recommend the AR's.

apaisncsu

hatterasman, thanks for this post and the inspiration to tackle this task

After reading this thread, I decided to give installation of AR downpipes a shot on my 2010 e61 535i xDrive. The most difficult part about getting the OEM DPs out were getting the v-bands unstuck and getting the O2 sensors out, but these issues caused much less stress than the fitment of the AR DPs.

I worked for 4 hours yesterday to try and get both DPs installed flush to the turbos with no success. The advice that I read elsewhere about inserting both pipes simultaneously was helpful. I was able to get the rear DP attached with the v-band fastener barely attached within the first hour. Then, I spent the next 3 hours trying to get the front DP flange to sit flush against the turbo flange. No matter how I positioned or rotated the DP, I could not get the two flanges to mate flush. I am almost convinced that either the front or back DP (or both) is/are slightly out of intended shape. If the curve just before the flange were slightly extended (i.e. longer curve length, same radius), then I think it would work. When I got the flange as close as it would go, it was in place on the right side (looking toward front of car) and there was a gap between the two flanges on the bottom left side. If I could rotate the rear of the front DP down and left, the gap would close, but the rear DP is in the way even though I have it rotated as far toward the block as it would go.

Did you have any issues like this?

hatterasman

I found lining them up to be the most challenging part of the install. If I recall correctly, there was something on the side of the block that I bent/moved to get an extra bit of rotation. I remember being concerned about vibration if the pipe remained in contact with the block. In the end, when I tightened the v-band for the pipe next to the block, the pipe moved away from the block. Probably can'take get a sheet of paper between the blocking and pipe, but it doesn't touch.

I guess all I have to offer here is to check if the pipe is truly touching the block or something you can move to get the extra bit of rotation you need