Exhaust options

[fmorelli]

Hi all, hoping some folks here have suggestions. I am working through my car now, and one of two remaining items I've not solved is around the exhaust. I have a catless downpipe, and would like to retain mid-cats, just for emissions, etc. My car is FBO, and I suspect the crimped passenger side pipe that goes to the muffler, and the scrunched muffler (passenger side) can't help things much. Also I have the quad pipe rear carbon fiber diffuser, and I'd like to run 4 pipes in the back to fix the aesthetic hole. Sure I could order an Eisenmann exhaust, but frankly $2,500 for two mufflers and some pipes seems ludicrous to me, not to mention I'd still have to solve the cat problem. I am not looking for lots of noise, mind you (e.g.; no Flowmasters ;-))

Here are some specific questions ... please feel free to address any or all of them.

- has anyone looked at the Becker exhaust for the Z4? It's about $1k which to me is very reasonable. (https://amzn.com/B01HSPKVYO)
- is the stock exhaust significantly limiting to an FBO N54?
- has anyone looked at just replacing the rear mufflers?
- if I left everything alone, anyone had the tips cut off and quads tips to go with the diffusers?
- Is there anyone else that makes something I should consider (cat-back or mufflers), beyond Eisenmann, Supersprint, Becker?

I'd prefer to be in the $1k solution zone, not the $2-3k zone.

Thanks for any helpful experiences you might share ...

Filippo

[Lurcher]

look to another n54tech location (.com) at the FrankenTurbo post, that should give you some idea about exhaust issues.

Power is lost at the cats, not the muffler Depends how "legal" you care to be...

[fmorelli]

Yup. As I said no DP cats but want to retain center pipe cats.

Filippo

[fmorelli]

Wow ... is it me or is this forum on life support? Surely I figured we'd have some folks that have done something with the rear side of their exhausts? Help a brother out :-)

Filippo

[ttuner]

i went with the remus axelback which basically just replaces the mufflers. a little pricey, but it sounds great.

I added the supersprint midpipes and wagner catless downpipes later to make a full exhaust. both of which needed to be modified however. I dont think the muffler/axelback section is a major restriction. the big restriction is the downpipes....

[fmorelli]

That's encouraging, knowing how much exhaust you are flowing to put down that kind of power. But I went to the Remus web site and could not find the mufflers for the 35i. Would you kindly post a link to what you are using?

I am specifically interested in axleback ... so this would be good.

Thanks,

Filippo

[ttuner]

http://www.m o d b a r g a i n s.com/Remus-Exhaust-E89-Z4.htm

mod bargains is banned here for some reason so i cant post a direct link or it will get blocked. but thats where i purchased.

[fmorelli]

Thanks. Interesting they only list 2.3 and 3.0 motor options. No 35i ... I've written Remus to see if one can order the axleback for the 35i. Thanks again.

Any other folks have recommendations or experience willing to share?

Filippo

[jannisa]

I run catless dp and the supersprint catback. The ideal stage for me was the stock exhaust with the catless dp or it's just I 'm getting older.

[fmorelli]

Originally Posted by jannisa

I run catless dp and the supersprint catback. The ideal stage for me was the stock exhaust with the catless dp or it's just I 'm getting older.

So you're not running any cats at all? I am running catless DPs, but I want to keep the secondary cats in place.

Filippo

[jannisa]

The main cats are on, the ss is a catback xpipe and mufflers unit.

[fmorelli]

I gave up sorting out a new, pre-made exhaust. My best bet was Supersprint from Turner, on sale for $2,100 but made in Italy to order and expected end of September (and if you've ever done business with Italian companies ... don't hold your breath on the delivery date).

So my car goes in for a full custom exhaust, scheduled end of August. It's a local company that has equipment to measure, design, and mandrel bend the system. We will cut the catless DP's and resize the outlet since the factory design constricts to the flange - instead we'll be full 2 1/2". They will do heavy metal, large high flow catalysts, but in the mid-pipes, and we'll bung them so we can still install factory DP post-cat 02 sensors. Mufflers and such are TBD. They will do an X pipe behind the cats. I'm expecting the cost of the system to come in under the Supersprint, installed, and with catalysts. Their work is excellent by all accounts - nice details like, they flair pipes, so they can sleeve and weld (versus butt weld).

I've attached two photos of their work - on a E39 540i and E28 M5.

Filippo