Equal-length exhaust discussion: new S55 sounds

[RugbyBro]

Originally Posted by matty088

Do you get smell from removing the rear cats? What about passing emissions? A cel?

In all honestly there is a tiny bit more smell but I only ever notice it during the cold start sequence when I’m pulling out of my garage - once warm I’ve never smelled any more fuel than normal. I drive with the windows open and dislike the smell of catless cars due to a sensitive nose; I don’t perceive any more fuel smell than stock. It won’t trigger a CEL as there are no sensors in the secondary cats. So long as your emissions test is an OBD scan (which most are from what I’ve seen on cars this new), you’re good to go. If you have to go to a state ref to do a visual inspection then I would imagine they’d fail you, and I don’t know what the threshold is for a particulate test tho I’ve never run into that. Goes without saying but there will be more particulates by removing the secondary cats so take that FWIW

[Kuucheki]

I really want to order the AA non resonated midpipes but waiting until they are readily available.

[bensf82]

Originally Posted by Kuucheki

I really want to order the AA non resonated midpipes but waiting until they are readily available.

Not a bad idea, ordered 3 weeks ago from AA, still no word. Totally fine waiting on it but basically being kept in the dark (sent 3 emails with no reply at all) is annoying and feels a bit frustrating after I dropped 1.3k on some curvy pipes.

[jeepin29]

Originally Posted by RugbyBro

Hmm is the vibration prevalent all the time or only on cold start? The DP rattle typically only happens when the metal is cold - once it’s hot it expands and forms a seal and the rattle will go away. The gaskets act to fill that space in between the pipes all the time so there is never any rattle. It can also be due to loose bolts at the DP.

If it’s not DP related and there’s no visible touching then I’d check all the clap points to make sure they’re cinched down correctly/tightly. I’m not exactly sure what else would cause it in the exhaust chain if it isn’t any of those things. Anyone else have ideas/input?

I am going to go ahead and replace the gaskets just to completely rule it out. The rattle does happen mainly during warm up, but not nearly as bad as in Tommy L Garage’s video. Hopefully the gaskets do the trick!

[Rokoz]

Originally Posted by jeepin29

I am going to go ahead and replace the gaskets just to completely rule it out. The rattle does happen mainly during warm up, but not nearly as bad as in Tommy L Garage’s video. Hopefully the gaskets do the trick!

I would check the spacing on your midpipe from the brace. I had some vibrating on cold start like you describe with my Dinan midpipe hitting the cross brace.

Still patiently waiting for my AA midpipe to arrive

[Blessm]

Originally Posted by jeepin29

I am going to go ahead and replace the gaskets just to completely rule it out. The rattle does happen mainly during warm up, but not nearly as bad as in Tommy L Garage’s video. Hopefully the gaskets do the trick!

If replacing the flange does not work I would also make sure the midpipe is not hitting the heat shield. When I installed mine last weekend the pipe was nearly touching the heat shield at the spot circled in red so I had to push the heat shield up in that spot. It was also touching the side of the heat shield in the spot circled in blue. I had to put the spacer block there before doing the final tightening.

[Commanderwiggin]

Originally Posted by Blessm

If replacing the flange does not work I would also make sure the midpipe is not hitting the heat shield. When I installed mine last weekend the pipe was nearly touching the heat shield at the spot circled in red so I had to push the heat shield up in that spot. It was also touching the side of the heat shield in the spot circled in blue. I had to put the spacer block there before doing the final tightening.

Be careful with pushing the heat shield up since the driveshaft is just above that and you'll make an even worse noise and potentially scuff up a nice CF driveshaft (if you have one).

[jballer123]

Has anyone tried to buy a equal length recently, I am waiting to place an order until we can actually get them

[Blessm]

Originally Posted by Commanderwiggin

Be careful with pushing the heat shield up since the driveshaft is just above that and you'll make an even worse noise and potentially scuff up a nice CF driveshaft (if you have one).

Thank you for that bit, I didn't know that. Luckily I only pushed it up slightly as it wasn't actually touching the heat shield at the red circled part. I just did it to give it a little more breathing room in case heat expansion made it touch

[mike@x-ph.com]

Originally Posted by jballer123

Has anyone tried to buy a equal length recently, I am waiting to place an order until we can actually get them

You need to pre-order or else its will be a long time before you get one. the batches are pre-sold before they are even delivered to Active.

The next batch will be available mid to late March

[Rjpacman]

Originally Posted by jballer123

Has anyone tried to buy a equal length recently, I am waiting to place an order until we can actually get them

Might as well just purchase & wait. I ordered my resonated midpipe during black Friday deals and just recieved it couple days.

[TheMaster1971NL]

I ordered one resonated late October 2020 and collected the midpipe yesterday.
Thanks Pure Turbos Europe (Peter Oleksy)

[mike@x-ph.com]

Originally Posted by TheMaster1971NL

I ordered one resonated late October 2020 and collected the midpipe yesterday.
Thanks Pure Turbos Europe (Peter Oleksy)

Congrats

[TheMaster1971NL]

Originally Posted by mike@x-ph.com

Congrats

Thanks!!!

[TheMaster1971NL]

I installed the midpipe and it's totaly different than stock or everything else! I love the sound. It sounds like an old 6 in line. Amazing

[kaiv]

Pipe ordered Nov 28 finally came in yesterday and.... it's missing all the clamps, fbrace, spacer block. Guess the wait continues!

[TheMaster1971NL]

Originally Posted by kaiv

pipe ordered nov 28 finally came in yesterday and.... It's missing all the clamps, fbrace, spacer block. Guess the wait continues!

😳😳😳

[Rokoz]

Originally Posted by kaiv

Pipe ordered Nov 28 finally came in yesterday and.... it's missing all the clamps, fbrace, spacer block. Guess the wait continues!

Man, I would be real upset. What did they say when you reached out?

[kaiv]

Originally Posted by Rokoz

Man, I would be real upset. What did they say when you reached out?

Mike@XHP said to email afish@Active. Did that. Followed up with Mike this AM to see if he can speed things up. Said to give Active a couple business days to reply. Just more waiting.

[Rokoz]

Originally Posted by kaiv

Mike@XHP said to email afish@Active. Did that. Followed up with Mike this AM to see if he can speed things up. Said to give Active a couple business days to reply. Just more waiting.

Bummer, I would call them - they've even said on this thread somewhere that they prefer folks to call

[jpsimon]

In case you missed it, in the "engine sound" walkthrough video for the new m3/m4 they specifically mention trying to keep the exhaust lengths the same (with one side crossing over to extend the length). He mentions this starting at 1:20.

Looks like they took some inspiration from the work our f80 members have done here. Just kidding... or am I?

My TopGear EL exhaust will for sale this summer after I'm able to place an order for the AWD M3. Anyone in the North East want to call dibs? Pickup only I don't want to ship

[Rokoz]

Originally Posted by jpsimon

In case you missed it, in the "engine sound" walkthrough video for the new m3/m4 they specifically mention trying to keep the exhaust lengths the same (with one side crossing over to extend the length). He mentions this starting at 1:20.

Looks like they took some inspiration from the work our f80 members have done here. Just kidding... or am I?

My TopGear EL exhaust will for sale this summer after I'm able to place an order for the AWD M3. Anyone in the North East want to call dibs? Pickup only I don't want to ship

They tried for sure, but it's still not the same length. It's 7 inches in difference between pipes and noticeable... GOOD NEWS is exhaust makers now know that there is a fix so it should come much faster than it did for the f8X