sparky300
06-28-2019, 10:54 AM
I know. Another header thread. I've searched many, many threads and I've found no conclusive answers anywhere to some of my questions concerning replacing the stock exhaust manifolds and adding hi-flow cats downstream. My state/city only runs an OBD readiness check, no visual or sniffer.
My intentions are to install my AA stage 1 supercharger on my 330i 6spd but before I go forward with that project, I want to replace the stock exhaust with headers and downstream cats. I plan on having AA install their canned tune and code out the post-cat O2's so those won't be an issue but I'd still like to retain the cats to reduce or eliminate the raw exhaust smell that's usually associated with a cat delete. So here goes...
- I'd prefer to avoid any installation issues, cutting, rewelding flanges, etc. so eBay headers aren't going to be a consideration.
- I really like the Supersprint headers and I'm not opposed to spending money on a quality part, but at half the cost I'm considering BimmerBrakes Gen 3 or AA. The only issue I can see with the BB headers is working around the tubes on the 4-6 to get them bolted up. It looks less than ideal for working space. I wish the original V1's were still available. The Magnaflow headers have changed design that don't appear to differ all that much from the OEM design so I'm not considering those. The BB headers aren't nearly as affordable as they were 5 years ago either.
I've also considered these from Schmiedman but the equal-length tubes look even more difficult than the BB headers when it comes to install the rear and the outlet flanges are specific to this kit and will only mate to their section 1, so other headers/exhaust will not be compatible down the road without modification should I decide to make any changes.
https://www.schmiedmann.com/en/product/16694-new?product=SCM5254
Additionally, this midpipe has to be lengthened to clear the 6 spd, so I might as well just cut and weld cats in place of the first resonator on my stock exhaust.
- Metal high-flow cats. Since I won't need the rear O2's, my thought was to remove the first resonator and install cats in its place.
- Two cats, single in, single out?
- Single cat with dual in, dual out?
- Should I also add a crossover after the cat?
Magnaflow has pretty much any configuration, single or dual to fit any installation, but I've read that some of them fail quickly or develop a rattle.
As it turns out, Schmiedman also has some metal 400 cells, although I haven't been able to find any reviews or comments. https://www.schmiedmann.com/en/product/1953710-new?product=SCM5254KATUR
In short, I'd like some feedback, positive or negative, suggestions, comments, issues with my plan...What I really need is some long-term, real world experiences. Wins, fails, etc. Any insight is greatly appreciated. Thanks.
My intentions are to install my AA stage 1 supercharger on my 330i 6spd but before I go forward with that project, I want to replace the stock exhaust with headers and downstream cats. I plan on having AA install their canned tune and code out the post-cat O2's so those won't be an issue but I'd still like to retain the cats to reduce or eliminate the raw exhaust smell that's usually associated with a cat delete. So here goes...
- I'd prefer to avoid any installation issues, cutting, rewelding flanges, etc. so eBay headers aren't going to be a consideration.
- I really like the Supersprint headers and I'm not opposed to spending money on a quality part, but at half the cost I'm considering BimmerBrakes Gen 3 or AA. The only issue I can see with the BB headers is working around the tubes on the 4-6 to get them bolted up. It looks less than ideal for working space. I wish the original V1's were still available. The Magnaflow headers have changed design that don't appear to differ all that much from the OEM design so I'm not considering those. The BB headers aren't nearly as affordable as they were 5 years ago either.
I've also considered these from Schmiedman but the equal-length tubes look even more difficult than the BB headers when it comes to install the rear and the outlet flanges are specific to this kit and will only mate to their section 1, so other headers/exhaust will not be compatible down the road without modification should I decide to make any changes.
https://www.schmiedmann.com/en/product/16694-new?product=SCM5254
Additionally, this midpipe has to be lengthened to clear the 6 spd, so I might as well just cut and weld cats in place of the first resonator on my stock exhaust.
- Metal high-flow cats. Since I won't need the rear O2's, my thought was to remove the first resonator and install cats in its place.
- Two cats, single in, single out?
- Single cat with dual in, dual out?
- Should I also add a crossover after the cat?
Magnaflow has pretty much any configuration, single or dual to fit any installation, but I've read that some of them fail quickly or develop a rattle.
As it turns out, Schmiedman also has some metal 400 cells, although I haven't been able to find any reviews or comments. https://www.schmiedmann.com/en/product/1953710-new?product=SCM5254KATUR
In short, I'd like some feedback, positive or negative, suggestions, comments, issues with my plan...What I really need is some long-term, real world experiences. Wins, fails, etc. Any insight is greatly appreciated. Thanks.