Opinion on Exhaust setup.

[HighschoolE30]

My 318is already has a header, but has the stock cat and everything else.

I have a magnaflow muffler (3" in and 3" out)

Really wanting to delete the heavy cat, not to metion the heat shield is lose, and just do a single pipe into the magnaflow.

Opinions?

[rares]

i say do it... do glance over the cat law in our area... just in case... but other than that... should sound pretty sweet

[harv]

Gonna be too loud.

John

[grippymonkey]

You may want a resonator to go with it too. I ran a straight through exhaust with a magnaflow muffler at the end on one of my other cars and it was just the right amount of loud. I had a stock cat on it still. I would guess you'd want a resonator to help out if you get rid of your cat.

[Balkanac]

3" could be a bit too big, you could loose power. M42 breathes the best with 2.25-2.5" pipes, i wouldnt go for anything more

[PNWDan]

3" could be a bit too big, you could loose power. M42 breathes the best with 2.25-2.5" pipes, i wouldnt go for anything more

3" is too big for the M20. Definitely too much for the M42. You will want a resonator of some sort or it will sound like a civic. On my m20 im running 2.5" with a glass pack in place of the cat. Sounds pretty good.

[MikeDE]

Leave it alone....if you're itching to do something, do a MarkD chip.
If you want an exhaust then buy a WHOLE exhaust...the Supersprint comes to mind.

Knock off the heat shield if it's loose. Don't make an already rare car ricey. It will never sound really good(in stock trim) anyway.

[aTron12]

So, it is possible to keep the stock cat, add a resonator and muffler? I'm looking at the Magnaflow 14815 but want to quiet it down a tad because they seem to get pretty loud.

[rjcaptsean]

The stock setup was a Cat, resonator and then the muffler:
http://www.realoem.com/bmw/partgrp.d...25&hg=18&fg=20
http://www.realoem.com/bmw/partgrp.d...25&hg=18&fg=10

The PO of my car installed two junk Cats to try to get out of paying for a new unit from BMW. Coupled with a Magnaflow muffler, it has a nice sound in the lower rpms but then gets SUPER raspy until 4000 rpms or so. Sounds like a really pissed off Bee. I found a new resonator from Autohausaz for $150 and a 50 State Cat from Magnaflow for $150. Looking at finally getting them installed next week. I'll let you know how it sounds.

[///digitalme]

i also suggest getting a whole system....i had aftermarket headers, oem piping, and magnaflow muffler...it sounded great below 3k rpm, after that it sounded like a civic... ended up ditching the headers, and magnaflow....installed oem headers, and aftermarket crappy muffler to pass emissions...

kamotors intake system is nice and deep if you like that sound.....gives it a unique sound

[///digitalme]

also ditch the heat shield

[rjcaptsean]

also ditch the heat shield

No problems with the cat and resonator melting the Guibo and CSB support rubber? How about melting the grease out of the slipjoint on the rear driveshaft?

I ask this because my heat shield is missing also.

[bmwguy325is]

It will never sound really good(in stock trim) anyway.

Spend the money on a good setup that balances the exhaust. Run twin pipes with a x over then a nice y pipe into a single 2.5.

[duleymane///iS]

I am running mine with straight pipe to the magnaflow muffler (no cat).. WAY... TOOO. LOUD!