Performance or Sound difference with Section 1

[MarcoPolo]

Not finding anything, or anything i do find leads me back to m3f. I was looking at moving over to a catless/resonated section 1. I'm currently running a euro section 1 and while i do have my stock US Section 1, i'd rather not chop it up so i'm going to save/hoard it.

Unless there are more suggestions, i was looking at the RE Rasp Pipe and the BW CPI Rasp Pipe. the major differences between the 2 are:
- the CPI has a crossover pipe - does anyone know how that would impact vs the RE Rasp pipe, which is essentially 2 seperate pieces.
- the CPI resonators are shorter/fatter than the RE rasp pipes' - does anyone know the difference between those? does this impact sound/tone? is one brand resonator better than the other?
- the CPI is ~$100 cheaper than the RE. is this a result of cheaper materials or just better pricing.

my current setup, fwiw, is euro headers, SS resonated section 2, SS Race Section 3.

Appreciate any insight anyone may have. Thanks. Pictures below are of the 2 different models.

[Inizes]

I’m not really an exhaust expert, but since you have the SS section 2 where the exhaust already combines into one track, I don’t know if you’d have much of an advantage of having a crossover pipe in section 1. CPI claims it helps balance back pressure before getting to section 2. Both systems are made from 304 stainless steel.

Rouge Engineering doesn’t offer a resonated section 2, which I would suspect is why they offer resonated section 1 for rasp control. I couldn’t find much on CPI racing either, so they may be in the same boat with having only a section 1 currently available. It looks like they used to make headers as well. I am thinking section 1 was the easiest place for manufacturers to put dual resonators since oem already had one placed there. Again, with your SS resonated section 2, I’m not sure if you really need a resonated section 1.

[tnord]

I have the CPI, but if you have euro headers you really should put cats in sect 1, keep the resonated SS, and call it good. CPI was a small company that generally produced good pieces and were bought up by ECS/Turner a couple years ago. Their RTX was generally thought of as the best rasp eliminator at the time if I remember right, and they claimed a repeatable 1-2hp from the crossover. I don't really care about that, I just care that when I paired it with the SS resonated X pipe, it absolutely did the job.

Euro headers are on my radar, at which time I'll put cats in sect 1.

https://www.youtube.com/watch?v=7Lo78RVj20o&t=87s

[Obioban]

Merging in locations other than the stock one tends to be pretty detrimental to power, would I wouldn’t expect good things from that.

[kermmmit7]

I have had agency power headers with double resonated section 1, supersprint single pipe resonated section 2 and supersprint race . I tried to use straight pipe section 1 and I put back my resonated section 1 in next day. More raspy and drone is not for me . Finally I installed cats in my section 1 because I was tired of smell when I was pulling something from my trunk. Also few of my friends complain about smell when they was driving behind me . After all those setups I can say that single resonated stock section 1 have similar sound, drone and raspy as catted section 1. Double resonated section 1 is the best if you want to kill rasp.
I don't think there is huge difference between rogue and cpi. In your situation I will try to install oem section 1 first to see if you like smell of catless. You can save some money if you are ok with smell and sound. If still too raspy install double resonated section 1.

[MarcoPolo]

thanks everyone for their opinions and feedback.

kermmmit7 that's actually a good idea. i was contemplating putting the OEM Section 1 back on to "give it a shot". i have read that the smell can be annoying but not annoying enough that other drivers smell it. that's frustrating.

Inizes so what you're saying is that with Rogue and CPI not creating sections 2's, their section 1's were designed around the use of the stock section 2. that's an interesting point. i moved to the SS Section 2 because it was just too raspy. with my current setup there is still some rasp, but i like it as to me it's an e46 unique rasp so i wan to have the presence there.

Obioban i assume you're referring to the CPI crossover section not existing in the OE section 1. understood. it's definitely 'different' but wasn't aware of the impact. i'm already aware of the section 2 pulling power being run as a single piece.


i wonder if going double-resonated section 1 (e.g. RE) and then going back to the OE section 2 would yield better results....OR just leave what i have alone and enjoy the car.

this gives me something to think about. thanks all.

[Inizes]

Rouge has a section 2, just not resonated.

I couldn’t find any section 2 products from CPI

[tnord]

I don't think they ever made any. They did headers and sect 1, and that was it.

[BigRussia]

I went from OEM Section 1, to OEM w/ 1 AR20, to Manzo 2.5" straight pipes (after reading on M3F thread about oversized 2.5" providing good gains across the powerband). I'm currently back to OEM Section 1 since any gain wasn't really noticeable on the butt dyno, and I didnt like the sound. It was too harsh and feel like it lost the exotic high pitch that the OEM section 1 provides, and w the AR20 it just sounded so meh for how little it reduced drone and rasp.

Here's my video of all 3 sound comparison WOT on the front straight of Homestead Miami Speedway.

https://www.youtube.com/watch?v=VO-nMJ5PKag

[r4dr]

I went from OEM Section 1, to OEM w/ 1 AR20, to Manzo 2.5" straight pipes (after reading on M3F thread about oversized 2.5" providing good gains across the powerband). I'm currently back to OEM Section 1 since any gain wasn't really noticeable on the butt dyno, and I didnt like the sound. It was too harsh and feel like it lost the exotic high pitch that the OEM section 1 provides, and w the AR20 it just sounded so meh for how little it reduced drone and rasp.

Here's my video of all 3 sound comparison WOT on the front straight of Homestead Miami Speedway.

https://www.youtube.com/watch?v=VO-nMJ5PKag

Interesting, the third pass sounded way quieter on my laptop speakers. Was that just something with the recording?

What muffler did you have for the three passes?

[BigRussia]

Interesting, the third pass sounded way quieter on my laptop speakers. Was that just something with the recording?

What muffler did you have for the three passes?

Yeah I noticed that too, and I think someone even commented on it. I think its just the recording as they were all shot on the same iPhone and the Manzo straight pipes were obnoxiously loud, but my car was always extremely loud with all 3 regardless as the section 3 'muffler' I had on for them was a MXP. Its one of those Gruppe M style exhausts that's basically just two resonators lol.