CTS Turbo High-Flow Catted Downpipe

[yusoslo]

subbed to see how the odor is and if they are much quieter than standard catless DP. I love my exhaust setup sound with catless DP but I have not driven with the top down on my F12 M6.

[SpeedProtocol]

I want to know if they still muffle wastegate rattle like the stock cats do?

[SpeedProtocol]

I had high flow cats on my transam(ls1) and it sounded glorious compared to others with stock cats or straight pipes. Its a more refined sound IMO.

[x35250]

Originally Posted by Droner

I want to know if they still muffle wastegate rattle like the stock cats do?

I will let you know how the rattle goes. It may be a while though. It's much too cold for me right now to work on the car and I'm still waiting for the new gaskets I ordered.

I am hoping the catted DP sounds more refined on this platform also. They sounded better to me on YouTube videos, but recorded audio always sounds different than in person.

[A3ch]

Originally Posted by x35250

The reason for getting these is to improve the sound of the exhaust note and gain a bit more performance. I could get to Stage II with these, but don't really want to wear out the stock clutch on the DCT.

Even with a Meisterschraft valvetronic catback exhaust on a Stage I custom tune, I always found the exhaust note lacking - too quiet and smooth. This held me back from fully enjoying the car.

To me, the catted DPs sound cleaner, have less pops/bangs, and are less raspier. They also smell less than catless.

These would pop the CEL because they are 200-cell while the stock DPs are 400-cell. The emission control system is smart enough to detect the difference. A high-flow 400-cell DP costs thousands of dollars more.

By getting a custom tune, I can finally get the sound I've been looking for all along with a tad bit more performance than a Stage I tune. I think it is well worth the cost.

Not to mention for places where they inspect the car visually it will pass that test. highly interested. Been looking exactly for this because my wife gets headaches with the windows down and I dont want to have to keep the windows up like I did with my 335i.
I wonder if MHD flasher has a way to defeat the cat

[A3ch]

Any word on smell? Fitment? I'm ready to pull the trigger....just still on the fence

[ECB]

Originally Posted by A3ch

Not to mention for places where they inspect the car visually it will pass that test. highly interested. Been looking exactly for this because my wife gets headaches with the windows down and I dont want to have to keep the windows up like I did with my 335i.
I wonder if MHD flasher has a way to defeat the cat

I would assume a visual inspection wouldn't be an issue with this car considering the location of the cats. My M3 was catless for a little while. My wife complained too, and honestly I didn't like it either so I added cats back.

[A3ch]

Decided to wait until I move into our new house before doing anything that involves flashing the car

[mike@x-ph.com]

Originally Posted by A3ch

Decided to wait until I move into our new house before doing anything that involves flashing the car

[x35250]

Originally Posted by A3ch

Any word on smell? Fitment? I'm ready to pull the trigger....just still on the fence

Still just have the parts sitting in a box. It's been too cold for me to work on the car.

Also, Chicane Motorsports (local tuner) recommends inspecting the injectors before the tune, but I am going to replace them instead. The injectors are original for my 2013 M5 with 58k miles. The miles aren't bad, but I think ten years is a good time to replace them for peace of mind. Add another $1200 plus installation!

I'll install the DP and charge pipes myself. The only concern I have with the charge pipes is the CTS unit looks to be equal shape/size on both sides, but the stock charge pipes are unequal. Wondering if this can cause any issues or whether a custom tune will mitigate the difference.

[x35250]

Weather finally warmed up a bit. Downpipes are going in tomorrow. Wish me luck and hope for a snag-free install!

[mike@x-ph.com]

Originally Posted by x35250

Weather finally warmed up a bit. Downpipes are going in tomorrow. Wish me luck and hope for a snag-free install!

Good luck and let us know how it goes

[x35250]

Well, everything was going well until I was trying to get the stock V-band clamps installed. Turns out the flange on the CTS Turbo downpipe is a bit thicker than the OEM downpipe flange. The stock V-band clamp will not close all the way. Not sure if I can buy another V-band clamp that will fit...

The CTS Turbo unit did not come with a V-band clamp.

[Craze]

I would have thought it should be certain size based off dia?
Can a machine shop machine it down??

Does the stock one actually clamp flush?? Not sure if it actually matters as it has a gasket in it

[mike@x-ph.com]

Originally Posted by x35250

Well, everything was going well until I was trying to get the stock V-band clamps installed. Turns out the flange on the CTS Turbo downpipe is a bit thicker than the OEM downpipe flange. The stock V-band clamp will not close all the way. Not sure if I can buy another V-band clamp that will fit...

The CTS Turbo unit did not come with a V-band clamp.

reach out to CTS , they'll take care of it

[x35250]

The stock V band clamp finally worked. I used a large set of split-joint plies to bring the two ends closer. I was scared to do this in case it snapped.

Driver side is done. Passenger side will have to wait. I just noticed the midpipe end of the downpipe is warped. The gaskets won't fit at all. I'll have to wait until CTS Turbo can send me a new passenger side unit. They do have a one year defect warranty, so, hopefully it won't be a problem.

I wasn't aware of a gasket between the turbocharger and the downpipe on the S63TU. Is there one? If so, do you know the part number?

I also replaced the eight coilpacks with Delphi units and both crankcase vent hoses. My spark plugs have about 5k miles on them, so I left them alone. Debating now whether to replace the O2 sensors now also since I have to wait for the passenger side pipe.

[x35250]

My stock downpipe setup did not have a gasket between the turbo outlet and the downpipe flange, as mentioned in this threat and by Craze: https://www.6post.com/forums/showthread.php?t=1704555

Part #18307553601
https://www.realoem.com/bmw/enUS/sho...diagId=18_0952

On mine, which is a 2013, it is just the two metal flanges secured by the V band clamp. There doesn't appear to have been a leak without the gasket either as there is no soot/carbon near the joint nor was there a whistling noise from the engine compartment.

Maybe I will just order them in case and have them available...

The BMW manuals are terrible!

[ECB]

If I recall, my 2013 did not have gaskets there either when I did my downpipes.

[Craze]

I assumed thats where it was after all this talk of wastegate rattles??

[x35250]

I just went ahead and ordered some Elring gaskets. I suspect BMW probably added these gaskets in later model years to help reduce any noise. Figured it is a very small cost to avoid taking things apart again. I also ordered all new O2 sensors.

CTS Turbo said I can send back the dented downpipe for them to repair it. Not sure why they won't just replace it. The section that's warped just slips into the mid-pipe anyway so it's not a functional. I guess it's not a big deal if it is repaired right...

I'm checking with my Indy shop first to see how much they will charge to fix the pipe. Might be cheaper and faster than shipping it back to CTS Turbo.

This has been quite the adventure. Just want to get my car back on the road.

[Craze]

If its damaged upon receipt im pretty sure you are entitled to replace or refund your choice
Dont see how they can dictate a repair

[M5_Raz]

Man, I don't miss the headaches of installing downpipes. I had problems with mine too. If I knew what I know now, I would've paid a shop to do it from the beginning.

That being said, mine doesn't have gaskets at the v-band clamp location either.