Supersprint & SCZA 2.5" System w/ Mods

[jbfrancis3]

Nice writeup and impressive skill man.

When you say sec 2 gave a more raw sound, this is with the setup pictured in post 1 with mini resonators and hjs?

I'll add my data once everything is on.

Thanks. I started with unresonated SS sect 2, then I tried adding an x-pipe, then I tried the small resonators, and now I have the SS resonator.

Obviously, less sound absorbing makes for more a dramatic note. I was trying to retain the nice [raw] sounds in the upper RPMs but not have these pockets of buzziness in the lower RPMs. They start and stop at certain RPMs and certain throttle inputs, which I found be more unpleasant than worth for the higher RPM note. I wanted to see if it were possible to dial these out (hence the incremental approach) but I couldn't.

Tbonem3 is right when he recently said that section 2 is where the rasp builds - that's what I found, too. So adding the SS resonator took care of all that but it noticeably quiets everything else, including upper RPMs, down. That's on relative basis, mind - I'm not saying you will end up with a quiet system by doing a resonated SS section 2.

I do have a quiet system, though, due to the SCZA muffler. That section 3 with an SS resonated section 2 is good exhaust setup for emphasizing an airbox.

I never did recordings of the initial setups. That would have been a good idea for this thread! The v-bands are great for this sort of screwing around, and other maintenance.

Lastly, my new OE muffler hangers (HJS brand) have pretty much failed within a year - don't buy! I'm not going to hope for a little more life out of OEM ($50 ea), so I just placed an order for Rogue's
https://www.rogueengineering.com/Rog...lly_p_302.html

[Slideways]

Brand new OE exhaust mounts will last a while. There is the OE metal bracket that was not transferred over to those aftermarket mounts. It give the mount a little more structure.

[Obioban]

Brand new OE exhaust mounts will last a while. There is the OE metal bracket that was not transferred over to those aftermarket mounts. It give the mount a little more structure.

Yes-- those mounts are incomplete.

[jbfrancis3]

Brand new OE exhaust mounts will last a while. There is the OE metal bracket that was not transferred over to those aftermarket mounts. It give the mount a little more structure.

Yes-- those mounts are incomplete.

Ah. FWIW, I'm only seeing a choice of OEM or aftermarket (HJS) these days.

https://www.fcpeuro.com/Parts/?keywords=18201401797

https://www.ecstuning.com/BMW-E46-M3-S54_3.2L/Search/SiteSearch/18201401797/

Unless you all have a different part # that would be helpful for someone else

[jbfrancis3]

I didn't fully comprehend Slideway's comments - now I get it. You mean this, separate bracket

https://www.ecstuning.com/b-genuine-bmw-parts/exhaust-mount-hanger-support-priced-each/18207839657/

[Obioban]

I didn't fully comprehend Slideway's comments - now I get it. You mean this, separate bracket
https://www.ecstuning.com/b-genuine-...h/18207839657/

Correct. 👍🏻

[Tbonem3]

The HJS are of good quality, but yes, slip them into the OE bracket.

Good feedback!

[jet_dogg]

It's crazy how much information is lost over the years when these cars change hands and POs rig things without subsequent owners knowing.

These exhaust mounts are notorious for tearing and yes it's a two part system.

[stash1]

I didn't fully comprehend Slideway's comments - now I get it. You mean this, separate bracket
https://www.ecstuning.com/b-genuine-...h/18207839657/

Yikes, $58 for a shitty stamped metal bracket-lol.

[Tbonem3]

prob dime a dozen on fleabay

[stash1]

prob dime a dozen on fleabay

Ya, think I def try to source some used ones for cheaper.

[jbfrancis3]

Yikes, $58 for a shitty stamped metal bracket-lol.

Tough pill for sure. Even more egregious if they're galvanized, which is what Rogue's site suggests by noting prone to rusting.

These brackets weren't on my vehicle when I purchased, hence the mistake of just replacing the mounts. Besides maybe keeping some of the lateral movement at bay, which could reduce the stress, I don't understand how the added brackets have a meaningful effect. Its not like the brackets provide any droop support.

Does anyone know why the factory mounts are so elaborate? They appear designed to take a lot of movement. Rogue's mounts (which I'm committed to trying) eliminate it.

[Obioban]

Tough pill for sure. Even more egregious if they're galvanized, which is what Rogue's site suggests by noting prone to rusting.

These brackets weren't on my vehicle when I purchased, hence the mistake of just replacing the mounts. Besides maybe keeping some of the lateral movement at bay, which could reduce the stress, I don't understand how the added brackets have a meaningful effect. Its not like the brackets provide any droop support.

Does anyone know why the factory mounts are so elaborate? They appear designed to take a lot of movement. Rogue's mounts (which I'm committed to trying) eliminate it.

Lots of expansion over the length of header to muffler when things get very hot?

[stash1]

Tough pill for sure. Even more egregious if they're galvanized, which is what Rogue's site suggests by noting prone to rusting.

These brackets weren't on my vehicle when I purchased, hence the mistake of just replacing the mounts. Besides maybe keeping some of the lateral movement at bay, which could reduce the stress, I don't understand how the added brackets have a meaningful effect. Its not like the brackets provide any droop support.

Does anyone know why the factory mounts are so elaborate? They appear designed to take a lot of movement. Rogue's mounts (which I'm committed to trying) eliminate it.

Lots of expansion over the length of header to muffler when things get very hot?

Ya, that, and I would imagine that the metal just simply provides support to the rubber portion (so as not to over extend/deflect)...similar (to a lesser degree) to any suspension joint where the metal housing encapsulates the softer bushing inside.

[jbfrancis3]

I’ve observed the system extends 1/4 to 1/2” inch doing a visual on the tips. And a quick look at the coefficient of expansion for stainless indicates a 3 meter length should grow 15mm over 300C delta (a guesstimate for the average increase).

Probably what I’m missing is I’m just doing street driving. Perhaps during track driving that temp delta is higher.