S54 Exhaust Setup Upgrade: Headers, Race Cats, X-Pipe, and Mufflers

[BlueM3Racer]

Been mostly lurking of late, but recently upgraded my exhaust setup on my '02 M coupe and relied a lot on this forum during my research so thought I'd add my setup to the available information by way of this thread. Many thanks to those S54 guys who have previously posted on this topic.

The huge 2017 Black Friday Supersprint sale at ECS spurred this upgrade that I'd wanted to do for a very long time. Funny thing is I found out about the sale with about an hour left so I was absolutely scrambling to read and find out information so that I could make an informed (very large lol) purchase...such as stepped vs non-stepped headers and would stepped headers fit the Z3 M coupe/roadster? Seemed up in the air based on information available so I skipped purchasing headers at the time and opted to figure out headers at a later date figuring I could at least go with a set of Euro E46 M3 headers if need be. Ultimately, per my research on stepped headers and S54 Z3 fitment I believe the consensus is that they will fit, but may require trimming of the 5 speed transmission housing. I ultimately opted not to go that route.

My car was previously equipped with just Remus Mufflers, all else stock exhaust-wise.

Here's what I did go with:

Active Autowerke S54 headers...euro/csl style headers. Opted for these over OE Euro E46 M3 headers because they maintained all of the OE 02 sensor locations and EGR bung...the euro M3 headers do not have the bungs for the post cat 02 sensors per my research. I'm by no means a mechanic and aimed to have a shop install all for me so I wanted easy/bolt-on, as little custom work as possible. For euro S54 headers I believe you can either add the bungs and/or code out the post cat 02 sensors via software.

Welds on these appear to be very nice, fit was perfect per my mechanic. Also came with OE BMW gaskets and hardware. Little tidbit I learned (via an 80+ page thread on M3forum) after purchasing these is that Megan S54 headers apparently used AA's design and some of the nicer batches of Megan headers likely come close as far as fitment for less than half the price (around 275-300), but keep in mind per those who bought Megan headers the gaskets they supply are junk, fitment may need work, and the shipping packaging was terrible. I experienced none of that with the AA headers.




Supersprint Section 1 with high flow cats...SS part #787502. 200 cell HJS cats. OE US cats are 600 cell? I've read different claims of the US cats being either 400 cell or 600 cell. Not a cheap option but, glad I sprang for these. Thank god for the ECS sale.

Supersprint Section 2 X-pipe...SS part #786033. X-pipe replaces factory H-pipe, which supposedly changes tone a bit and is advertised as being slightly higher flowing.



Supersprint Section 3 Sport mufflers...SS part #786016 & #786036...these are pretty. My experience with SS on my old S52 E36 M3/4, was that the sound is fairly mild until WOT.



Also popped on a Motion Motorsports metal engine underpanel, replaced both engine mounts & original bushings/rubber in various places, a rod bearing service, and a valve adjustment. I was told my bearings looked very good (94k miles on them, pics below) and had about 4 valves out of spec - not too bad.

Impressions: Since the bearings were done at same time, I've been keeping RPM's under 5500 until those have been heat cycled. Given that I haven't really heard it scream yet, but the exhaust note down low is much deeper and boomier so far. Less raspy than before as well.

Likely to have it tuned in near future to bring it all together...car still has a Dinan stg. 1 tune and I'm sure is leaving some power on the table as-is. No CEL to date after about 60 miles, but from my understanding it will be a little while before you really know whether race cats, etc. will throw a code or not.

[mercedesc63]

Haha your almost my mod twin and your in the exact opposite color!
My car... ‘02 Estoril Blue/Black M Coupe Slicktop - 18” HRE 445R 18x8.5 and 18x10, Wilwood 4 piston front BBK (not installed yet), TC Kline D/A, stainless steel headers, stainless steel straight pipes section 1 & 2 (no cats), eisanmann race exhaust, alcantara headliner, thicker steering wheel, custom throttle settings.

i just coded out all my “smog” settings (o2 sensors, cats, etc) so no CEL and I accomplished this using martyns s54 tool “ecu works”. In addition i was able to change my throttle settings to make them completely linear, add burble, and change my rev limiter (if i wanted to i didn’t). I personally would have went with no cats on your car because it adds about 30hp+ with your mods, i think it will add just half or so.

Post up some more pictures of your car to show the wheel/ bbk!

[BlueM3Racer]

Haha your almost my mod twin and your in the exact opposite color!
My car... ‘02 Estoril Blue/Black M Coupe Slicktop - 18” HRE 445R 18x8.5 and 18x10, Wilwood 4 piston front BBK (not installed yet), TC Kline D/A, stainless steel headers, stainless steel straight pipes section 1 & 2 (no cats), eisanmann race exhaust, alcantara headliner, thicker steering wheel, custom throttle settings.

i just coded out all my “smog” settings (o2 sensors, cats, etc) so no CEL and I accomplished this using martyns s54 tool “ecu works”. In addition i was able to change my throttle settings to make them completely linear, add burble, and change my rev limiter (if i wanted to i didn’t). I personally would have went with no cats on your car because it adds about 30hp+ with your mods, i think it will add just half or so.

Post up some more pictures of your car to show the wheel/ bbk!

Yes, very similar mods. Beautiful car you've got, love Estoril of course. I've got an alcantara headliner as well! Funny.

Thank you for the info on the ECU works tool. I'm not familiar, will have to look into that option. So you kept your rev limiter at 7600 RPM? Part of the reason I did the bearing service was for the peace of mind if I did decide to raise the limiter to 8100.

If anyone else has any recommendations on a tune I'm all ears. I've got Epic motorsports a couple counties away, same for active autowerke, my mechanic who did this exhaust install uses/recommends a TTFS tune, TMS race shark a more cookie cutter option, and I think read that Ken Z3speed4me/FMCFad01 had Nick G do a tune for them (which would also be local).

Supersprint claims their race cats don't give up much, if any, power versus going catless. I'm sure it's a few hp though and I definitely had an internal debate on which direction to go. I'm glad I ponied up though for a few reasons, the SS section 2 is a super high quality part. HJS seems to be very well respected and the longevity of the cats should be on par with OEM, likely lasting me the rest of the car's life. Active and CPI offer some lower end race cat options too but the longevity of their options certainly comes into play.

As far as wheels/bbk setup my LM's are 18x8 and 18x11. Have liked the Wilwood BBK thus far, but can't say I've really put it through the paces if the track is your goal for that kit.

Some (older) pictures:

[mercedesc63]

Just my .02 my car was once tuned to 8100 keep in mind my engine was replaced in 2007 by the dealership under warranty with a brand new late production 07 s54 with the new bearings and other revised internal components. I lowered back my rev limiter it out of fear for long term and even short term health of my engine, according to my research more e46 m3s had rod bearing failure and that it was due to the raised limiter. In addition dinan used to raise the rev limiter on z3m s54s till a few cars had rod bearing failure and they stopped keep in mind these were the days of Dinan cutting the frame on z8s to fit the odd shaped headers.

[FINZ]

If anyone else has any recommendations on a tune I'm all ears. I've got Epic motorsports a couple counties away, same for active autowerke, my mechanic who did this exhaust install uses/recommends a TTFS tune, TMS race shark a more cookie cutter option, and I think read that Ken Z3speed4me/FMCFad01 had Nick G do a tune for them

Randy at Epic did a great job with my tune. Exact exhaust setup as you with exception of Euro headers.

[BlueM3Racer]

Randy at Epic did a great job with my tune. Exact exhaust setup as you with exception of Euro headers.

Good to know. Thanks, FINZ, definitely read some of your posts on the S54 exhaust topic during my research.

[CaliAgents]

Very nice exhaust upgrade mayn! Good stuff for jumping on the 'once in a lifetime' SS/ECS Black Friday sale. That more than likely won't happen again! Get us some sound clips if possible homie!

I don't recall seeing anyone bullet-proofing their VANOS here whereas on M3forum it is extremely commonplace for longevity. Were you planning on doing that eventually?

I also second Martyn's ECUWorx MSS5X Binary Modification Tool. It's not really a tuner but allows one to code out a few exhaust-related sensors, change rev limiter, change cat protection threshold, etc. I fine tuned my own throttle response map as well and absolutely love it for that purpose alone. If you want to extract more power then a proper tune is in your cards.

[BlueM3Racer]

Very nice exhaust upgrade mayn! Good stuff for jumping on the 'once in a lifetime' SS/ECS Black Friday sale. That more than likely won't happen again! Get us some sound clips if possible homie!

I don't recall seeing anyone bullet-proofing their VANOS here whereas on M3forum it is extremely commonplace for longevity. Were you planning on doing that eventually?

I also second Martyn's ECUWorx MSS5X Binary Modification Tool. It's not really a tuner but allows one to code out a few exhaust-related sensors, change rev limiter, change cat protection threshold, etc. I fine tuned my own throttle response map as well and absolutely love it for that purpose alone. If you want to extract more power then a proper tune is in your cards.

Andrew! Good to hear from you, man. Hope all is well and that touring you have in your signature sounds awesome! What is the Individual color may I ask? My dad has a super low mileage 2010 328xit M-Sport 6 speed in silver/grey that he's contemplated selling and I've thought of scooping up, but I've been very happy with my e90 335d (and vastly prefer my 335d color combo and powertrain) so haven't pulled the trigger.

Will work on sound clips and better pics. My coupe could use some fresh paint, I'm working on making it great again lol. This work was a big step in that direction. The FL sun finally got to my paint over the past year and a half before I could convert my carport into a garage, which I've now done.

My mechanic (who has a large E46 M3 clientele) actually did recommend eventually doing a Vanos bulletproofing. He uses Beisian product(s)..."vanos overhaul, anti rattle kit, oil disc, upgraded bmw internals, and includes a valve adjustment". I'm not on my original vanos...bad vanos failure just outside my original CPO warranty and had a big Vanos job done via BMW goodwill ~20k miles ago. I do plan to have this work performed in the future, good call.

The future wish list:
ecu tune
paint job
wheel refinish
upgrade rear diff
subframe reinforcement
I will likely stop short of a CSL airbox/alpha N setup, but hey who knows

Should keep me busy for a while.

[CaliAgents]

Jason, all is well here mayn! Several reasons as to why I bought a 2019 F31:
1.) No G21 or any BMW wagon for the US market for a long while
2.) Love wagons and couldn't afford an E63 S Estate
3.) Do not like SUVs or crossovers save a select few
4.) Welcomed my new son earlier this month!

I'm not going to reveal the color just yet but I selected the color sight unseen =) Absolutely no regrets once I saw it in the flesh as well as the entire car. One of the only "I wishes" was that we got shafted with only the B46 turbo-4 engine. It is a very smooth and relatively powerful (plenty for a DD) motor but oh how I wish we had the option to order it with the B58 turbo-6 engine. Your E90 is adorned with a gorgeous color combination, definitely hard to let go for a silver over grey M-sport touring. I had a couple of greens on my short list of Individual paint offerings.

Glad to hear you have a competent mechanic who is very familiar with the S54B32. I like to tackle most jobs myself but the Vanos is one area I will probably let a seasoned enthusiast/mechanic take over. Beisian is the way to go from what I gather as well.

Your future upgrade list looks very proper and will surely keep your enthusiasm up as opposed to knocking everything out in one fell swoop. Again, glad to see one of the OG M Coupers still perusing the boards here. I miss the good ol' days when this place was very active and poppin' you feel me?!

[BlueM3Racer]

Jason, all is well here mayn! Several reasons as to why I bought a 2019 F31:
1.) No G21 or any BMW wagon for the US market for a long while
2.) Love wagons and couldn't afford an E63 S Estate
3.) Do not like SUVs or crossovers save a select few
4.) Welcomed my new son earlier this month!

I'm not going to reveal the color just yet but I selected the color sight unseen =) Absolutely no regrets once I saw it in the flesh as well as the entire car. One of the only "I wishes" was that we got shafted with only the B46 turbo-4 engine. It is a very smooth and relatively powerful (plenty for a DD) motor but oh how I wish we had the option to order it with the B58 turbo-6 engine. Your E90 is adorned with a gorgeous color combination, definitely hard to let go for a silver over grey M-sport touring. I had a couple of greens on my short list of Individual paint offerings.

Glad to hear you have a competent mechanic who is very familiar with the S54B32. I like to tackle most jobs myself but the Vanos is one area I will probably let a seasoned enthusiast/mechanic take over. Beisian is the way to go from what I gather as well.

Your future upgrade list looks very proper and will surely keep your enthusiasm up as opposed to knocking everything out in one fell swoop. Again, glad to see one of the OG M Coupers still perusing the boards here. I miss the good ol' days when this place was very active and poppin' you feel me?!

Absolutely on the touring...SO much utility, F31 is a looker, and solid performance. Easy access to the roof rails bc of ride height, I love to borrow my parents'. They've had either a BMW 3 or 5 series touring or X5 in the stable just about my entire life. I love green cars and the M57 diesel has treated me well so far. A true torque monster.

Congratulations on your son! I had my first (a daughter) in late 2017, it has been incredibly rewarding. This past xmas she got a BMW Baby Racer III from Santa...I know we'll do our best to help them grow into car nuts. For me it really started to get fun around 6-8 months...they start to make incredible leaps then and it just keeps getting better. Excited for you and that journey.

Yes, missing the good old BF.c days myself. Hadn't posted in year prior to this post and it appears to be very dialed back versus what it once was. Good car culture on Instagram...I'm on there as "jcardsrule" if anyone cares to follow.

[BlueM3Racer]

Some updates on my end. Fast forward 6 months and I've only got about 700 miles on the setup so far and in that time have only been "zinging" it for the past 200 of those non break-in miles. I had found an old post by Randy Forbes where he recommended keeping the RPM's under 4000 RPM for 500 miles after rod bearing replacement service so I tried to adhere to that as opposed to the 5500 RPM's my mechanic had told me.

Despite my current Supersprint Sport mufflers (part numbers 786016 and 786036) not being broken-in yet, I'm fairly certain they are not going to do it for me tone-wise. I've placed an order with ECS during their recent sale for Supersprint Race mufflers (part numbers 043106 and 043136). Backordered and still months away with delivery date already pushed back once by ECS, but I'm excited. It's not my daily so I'm looking for LOUD to accentuate the characteristic S54 ripping angry chainsaw sound. The cans on the race muffler appear to be smaller, tips different, presumably they will be lighter, but should flow the same as the Sport mufflers per SS. Everyone on this forum seem to use the Supersprint Sport mufflers so that is what I initially went with. Had I been using the Supersprint online catalog as opposed to just ECS's website the first time around I probably could have avoided buying mufflers twice, but live and learn.

Before the search function went bust recently I searched the Race muffler part numbers etc. on this forum and couldn't come up with anything. Surely someone's run them, but feels like I'm wading into uncharted territory as far as Z3 M coupe/roadster at least (bc obviously the E46 M3 guys love their SS Race mufflers).

No CEL on this setup as of yet. Feels great so far, lots of additional mid-range power. Plan is to get the exhaust tone dialed in to my liking and then go after a tune.

[BlueM3Racer]

Well my Supersprint Race mufflers arrived the other day. Unfortunately, one of the tips was bent on arrival so round and round we go with ECS Tuning...now right back into another 2.5-3 month wait for a replacement unit for the side that showed up damaged. We'll see if they can/will accelerate the process, but I have my doubts.

Initial impression is that the Race mufflers are quite a bit lighter than the Supersprint Sport mufflers. And the muffler canister is probably about 30% smaller on the Race than that of the Sport. As well as a different tip design. I'm thinking the Race version will meet my expectations for my car's exhaust tone.

Some pictures:



To compare SS Sport vs SS Race...
Sport:

Race:

[BimmerBreaker]

The staggerd tips almost looks wrong too? Shouldn't the inner pipe be the one that extends out a little further?

[mpire]

This seems like a really complicated process.

I don't get the whole bit about the Euro headers not having the post cat O2 sensors. They are post cat, on the euro midpipe where the cats are on the euro setup.

If you are running aftermarket cats you may still get the error and you might as well just have the secondary O2 sensors coded off and remove them from the car with the tune when you get rid of the air pump as neither do much good.

Cats are still a good idea if you don't like cleaning soot off the back of your car. Plus the smell...

I'm in the process of sticking the S54 midpipe on the press car just to see if I can make it fit.

I love the sound of the euro resonator.

[BlueM3Racer]

The staggerd tips almost looks wrong too? Shouldn't the inner pipe be the one that extends out a little further?

Noticed this too. The pics accentuate a larger stagger than is seen in person...as the SS Sport sits on the car currently you can't even tell, the tips appear even with no stagger. Maybe I'll grab a pic from above tonight.

This seems like a really complicated process.

I don't get the whole bit about the Euro headers not having the post cat O2 sensors. They are post cat, on the euro midpipe where the cats are on the euro setup.

If you are running aftermarket cats you may still get the error and you might as well just have the secondary O2 sensors coded off and remove them from the car with the tune when you get rid of the air pump as neither do much good.

Cats are still a good idea if you don't like cleaning soot off the back of your car. Plus the smell...

I'm in the process of sticking the S54 midpipe on the press car just to see if I can make it fit.

I love the sound of the euro resonator.

LOL no kidding re: complicated. Much paralysis by analysis achieved researching and trying to figure out what was compatible E46 M3 vs S54 E36/8. My longtime trusted indy mechanic closed up shop prior to this work so my aim was full bolt on, no fuss, wanted everything to fit nice and easy with no CEL's. Things that threatened that: Euro Section 1 is slightly longer than US Section 1 & would require cutting to fit, SS v1 stepped headers would require clearancing of existing 5spd transmission (I know you're a big 6 speed proponent so likely not an issue for those with 6 speed).

As for the AA headers vs OE Euro S54 headers, what I meant is the AA headers give you a nice place to plug in the post cat O2 sensors if you run catless which I was considering at the time as well as them having the EGT bung welded in already. For what it's worth I have had no CEL with the SS race cat setup to date on 1200 miles driven...no coding out of post cat O2 sensors required, which is a nice thing imo.

That said, were I to do it over I'd likely have gone with OE euro S54 headers. AA headers chinese made at end of the day and kind of bothers me. There is a slight rattle on startup from them that perhaps will need to be tracked down too.

After reading countless M3forums S54 header threads I think I'd only consider the following headers: any of the SS non-stepped or stepped variants, OE Euro S54 catless headers, and CPI stepped headers (made in Taiwan, ultimately unsure if these would require clearancing of the 5 spd transmission). There's a lot of junk out there fitment wise and this is a forever car for me. I've obviously already failed on this project at the "do it once do it right" mantra. Maybe this thread will help some people out.

And Euro Resonator is unobtanium no?

[BimmerBreaker]

After reading countless M3forums S54 header threads I think I'd only consider the following headers: any of the SS non-stepped or stepped variants, OE Euro S54 catless headers, and CPI stepped headers (made in Taiwan, ultimately unsure if these would require clearancing of the 5 spd transmission). There's a lot of junk out there fitment wise and this is a forever car for me. I've obviously already failed on this project at the "do it once do it right" mantra. Maybe this thread will help some people out.

Funny because I think I read the same thread on there and my take away was that the cheaper ones are a wonderful value. Fitment on some is iffy (though by most accounts, in recent years fitment has REALLY gotten good) but the gains on the cheaper ones are still there, and at least for me - I don't mind spending a little time getting something to fit if it saves me $800+ over the "real" version. YMMV of course

[mpire]

LOL no kidding re: complicated. Much paralysis by analysis achieved researching and trying to figure out what was compatible E46 M3 vs S54 E36/8. My longtime trusted indy mechanic closed up shop prior to this work so my aim was full bolt on, no fuss, wanted everything to fit nice and easy with no CEL's. Things that threatened that: Euro Section 1 is slightly longer than US Section 1 & would require cutting to fit, SS v1 stepped headers would require clearancing of existing 5spd transmission (I know you're a big 6 speed proponent so likely not an issue for those with 6 speed).

The 5 speed and EURO E36 6 speed (NOT E46) transmissions are all the same dimensions as far as I can tell. It doesn't make any difference with headers. If it fits one it fits with the 5 speed it fits with the 6.

As for the AA headers vs OE Euro S54 headers, what I meant is the AA headers give you a nice place to plug in the post cat O2 sensors if you run catless which I was considering at the time as well as them having the EGT bung welded in already. For what it's worth I have had no CEL with the SS race cat setup to date on 1200 miles driven...no coding out of post cat O2 sensors required, which is a nice thing imo.

My understanding is that latest iterations of the MSS54 don't even use the EGT sensor. I welded in a bung on one, but not on the other S54. No differences to be honest. Plus you won't get the benefits of the headers without software. Kassell performance can turn around the tune in less than 3 days and its worth at least having a look at the options. I got "performance" cats and still threw a light. The MSS54 is pretty smart. There are lots of places to save money in your setup that could be spent on an inexpensive tune. I have had them all at this point. The worst is by far Dinan.

That said, were I to do it over I'd likely have gone with OE euro S54 headers. AA headers chinese made at end of the day and kind of bothers me. There is a slight rattle on startup from them that perhaps will need to be tracked down too.

Having tried Euro, Euro UK, SS Stepped Headers, and Midpipe, as well as the Euro midpipe, its all a wash. The cats make a difference on livability. The mid pipes are the same length for US and Euro cars, the difference is only in location of the cats, and 400 CPI US vs 200 CPI Euro catalytic converters. I would recommend you code out the post CAT O2 sensors for your car, but definitely go with some high flow cats to keep your rear paint from being damaged on your priceless S54 Coupe. Randy massaged a set of those $150 SS knockoff headers from fleabay on the SG car, and honestly other that a custom bracket he machined to keep the two mid pipe connections together, its been trouble free. He didn't like the headers rubbing the insulation, so he essentially bolted them together. Pipes are pipes, the benefit is moving the cats to the bottom of the car in the air stream instead of inside your engine bay degrading your plastics and making them even more brittle. Fancier headers may net you 3 or 4 more HP, but I don't know if its worth the added cost.

In short, I would buy some used Euro Headers for $250 or some Fleabay SS Knockoffs for $84 (with free shipping) and then spend the cash to have them ceramic coated to reduce engine bay temps a touch and then install them and be happy. Get all new gaskets and copper nuts from bimmerbum.com because you never know. I would go with a bit longer factory studs on the Chinese flanges, but they are pennies each. If you already got some fancy headers, then they are just fine. If you haven't bought anything, save your cash.

And Euro Resonator is unobtanium no?

Yeah, I have two of them in use at the moment on the AW and SG. I would buy another one if I ran across it just to have. The Press car may be getting an H-pipe to try it out at some point. I'm sure you could have one fabricated into your existing H-Pipe.

All 4 of my cars are running various versions of SuperSprint. I find that having someone jam a wooden broom handle into the exhaust and forcing it into position while you bolt everything in place is the only way to get them to line up to my tastes. If I take off the exhausts, I remove the hangers from the trunk floor, I never mess with the muffler bolts to the hangers. Also, use nyloc/locking washers/and locate to make sure they don't vibrate loose. You don't want to walk out and find they aren't aligned one day. Its annoying and then you gotta spend all that time re-aligning them again.

[BlueM3Racer]

Funny because I think I read the same thread on there and my take away was that the cheaper ones are a wonderful value. Fitment on some is iffy (though by most accounts, in recent years fitment has REALLY gotten good) but the gains on the cheaper ones are still there, and at least for me - I don't mind spending a little time getting something to fit if it saves me $800+ over the "real" version. YMMV of course

Definitely some value there! If I had a 100k+ mile E46 M3, the Megan headers seem great...Megan Racing just copied the AA header jig...it's the Chinese trade war situation played out via car parts lol. S54 M coupe being a "forever" car for me and paying someone else to install them proper headers fitment had value to me. AA's marketing claims they test fit each pair of their headers back in the US and they include OE gaskets & hardware where Megan does not.

As far as Supersprint's (reverse) tip stagger in-person, as promised a pic of how the SS Sport look from above (don't mind the peeling rear bumper...ugh):


The race being lighter, maybe will be easier to get them lined up proper?

The 5 speed and EURO E36 6 speed (NOT E46) transmissions are all the same dimensions as far as I can tell. It doesn't make any difference with headers. If it fits one it fits with the 5 speed it fits with the 6.

My understanding is that latest iterations of the MSS54 don't even use the EGT sensor. I welded in a bung on one, but not on the other S54. No differences to be honest. Plus you won't get the benefits of the headers without software. Kassell performance can turn around the tune in less than 3 days and its worth at least having a look at the options. I got "performance" cats and still threw a light. The MSS54 is pretty smart. There are lots of places to save money in your setup that could be spent on an inexpensive tune. I have had them all at this point. The worst is by far Dinan.

Good info as always, Mpire. The Supersprint website itself reflected that the SS V1 stepped didn't fit the Z3, but per forum research supposedly they do with some (mild?) clearancing of the transmission housing. I just didn't want to deal with that. Wanted to bring my new mechanic a "clean" project.

Certainly agree that someone could save quite a bit of $ versus my setup...biggest area being the section 1. SS catted Section 1's quality/longevity + "forever" car for me + ECS big sale = win. Getting the S54 sound dialed-in is all part of the fun. I will probably now forever be tempted to finish off the full SS setup and swap my AA headers to SS. And, yep, I plan on either a Nick G or Epic Motorsports in-person dyno tune in place of the cookie cutter Dinan stage 1 it had when I bought the car 15 yrs ago. Hopefully be in the 300whp neighborhood then. Appreciate the recommendations.

Having tried Euro, Euro UK, SS Stepped Headers, and Midpipe, as well as the Euro midpipe, its all a wash. The cats make a difference on livability. The mid pipes are the same length for US and Euro cars, the difference is only in location of the cats, and 400 CPI US vs 200 CPI Euro catalytic converters. I would recommend you code out the post CAT O2 sensors for your car, but definitely go with some high flow cats to keep your rear paint from being damaged on your priceless S54 Coupe. Randy massaged a set of those $150 SS knockoff headers from fleabay on the SG car, and honestly other that a custom bracket he machined to keep the two mid pipe connections together, its been trouble free. He didn't like the headers rubbing the insulation, so he essentially bolted them together. Pipes are pipes, the benefit is moving the cats to the bottom of the car in the air stream instead of inside your engine bay degrading your plastics and making them even more brittle. Fancier headers may net you 3 or 4 more HP, but I don't know if its worth the added cost.

In short, I would buy some used Euro Headers for $250 or some Fleabay SS Knockoffs for $84 (with free shipping) and then spend the cash to have them ceramic coated to reduce engine bay temps a touch and then install them and be happy. Get all new gaskets and copper nuts from bimmerbum.com because you never know. I would go with a bit longer factory studs on the Chinese flanges, but they are pennies each. If you already got some fancy headers, then they are just fine. If you haven't bought anything, save your cash.

Yeah, I have two of them in use at the moment on the AW and SG. I would buy another one if I ran across it just to have. The Press car may be getting an H-pipe to try it out at some point. I'm sure you could have one fabricated into your existing H-Pipe.

All 4 of my cars are running various versions of SuperSprint. I find that having someone jam a wooden broom handle into the exhaust and forcing it into position while you bolt everything in place is the only way to get them to line up to my tastes. If I take off the exhausts, I remove the hangers from the trunk floor, I never mess with the muffler bolts to the hangers. Also, use nyloc/locking washers/and locate to make sure they don't vibrate loose. You don't want to walk out and find they aren't aligned one day. Its annoying and then you gotta spend all that time re-aligning them again.

I've got the SS x-pipe...I'm good with some rasp just want the car to scream. The OE H pipe flows great by all accounts. May have to try your broomhandle trick.

As far as the US vs Euro section 1 length the following posts by Z3speed4me and Randy are what tipped me off on that:




Maybe not enough difference in length to matter? But again I was aiming for "tried and true" bc of the limited exhaust info avail on S54 Z3 vs the dearth of info out there for E46 M3. You'd think only the Section 2/Section 3 would be different between the two cars, but the above pic pushed me towards the SS catted Section 1 rather than buying used cats from Europe that would potentially need to be shortened.

Hopefully this is of some help for the next guy to make an informed decision.

[CaliAgents]

I just revamped my exhaust system again and went with all new OE euROW parts: headers, catted section 1, and resonator. Cat-back exhaust remains the same, MK Motorsport. Although I miss some of the raucousness associated with my former catless + AR20 resonated setup, I am much happier knowing that I'm not spewing a bunch of crap into the atmosphere and with a young son at home his health is paramount. On the flip side, the sound is still a riot (but more mature and toned down) and the resonator allows the S54's raspy character to shine through just the right amount. Also, I like many of you just love tinkering on the Z platform so if I can find an excuse to wrench on it I'll do it! EGT is still active, post cat sensors tuned out.

I also coated the inside and outside of the headers and resonator as well as the outside of the section 1 myself using Eastwood's Internal Header Coating product. So far so good with no signs of flaking. Sucks about the bent tip but ECS should do you right so hopefully they can fast-track the replacement. Since you already have SS' catted section 1 and muffler, I say complete the package with a set of their stepped headers as well.

[CaliAgents]

Here are some random photos of my recent exhaust journey.

Eastwood's Internal Header Coating which can also be used externally. The internal nozzle & tubing is sold separately. Good for 1800 F! DIY 'til my casket drops mayn!


Nicely coated inside and out bruh!



My outdoor spray station =)


OE BMW EGR/SAP delete plate, yeeeee!!!!


Love these OE BMW N54 slightly extended length E-torx studs




Brand spanking new OE EuROW catted section 1


EuROW resonator


EuROW Section 1 coated beautifully, yeeeeeee!!!!


EuROW Section 1 and EuROW resonator bolted up and ready to go on as a mated pair you feel me?!


EuROW Section 1 getting the Eastwood treatment on its exterior.

[fmcfad01]

Very nice Cali.

[Dirtsquirt]

@caliagents where did you find your resonator at

[BlueM3Racer]

For sure absolutely gorgeous, Andrew. Great job on the finish. I'm sure it still sounds excellent and your MK Motorsport section 3 both rare and the dtm tips design beautiful.

Cross checking part numbers for EuROW section1 on ECS it appears there's a different PN for S54 Z3 vs E46 M3 which could explain a potential length difference. Thank you for sharing!

S54 Z3 EuROW Section 1: 18307832489
E46 M3 Euro Section 1: 18307832488

[CaliAgents]

Very nice Cali.

I try homeslice =)

@caliagents where did you find your resonator at

One of my contacts in Europe did a trade with me. He got it through the dealer network there.

For sure absolutely gorgeous, Andrew. Great job on the finish. I'm sure it still sounds excellent and your MK Motorsport section 3 both rare and the dtm tips design beautiful.

Cross checking part numbers for EuROW section1 on ECS it appears there's a different PN for S54 Z3 vs E46 M3 which could explain a potential length difference. Thank you for sharing!

S54 Z3 EuROW Section 1: 18307832489
E46 M3 Euro Section 1: 18307832488

Yes, definitely different parts! Yeeeeehaaaaa!! I say "EuROW" because it's only the US that has specific emissions equipment compared to the ROW (rest of world). Correct me if I'm wrong but the the whole 'Euro' specificity isn't exactly accurate.

[CB750]

where did you find your resonator at

There appears to be one for sale in the classifieds; it's a NLA part and berry, berry, 'spensive:

https://www.bimmerforums.com/forum/s...t-18107831421)