Author Topic: Replacement Exhaust Systems (Read 4520 times)

BlueBMW · « **on:** February 01, 2010, 08:00:19 PM »

Tax money came in, so time to "invest" some into the 318is. Right now I have a super noisy annoying fart can (from the PO) I cant stand the thing! Its loud inside, its VERY loud outside and it buzzes like an angry bumblebee! Its gotta go! So, looking for some simple suggestions... I am planning on re-installing a catalytic converter (the PO removed that too) And I also need a decent muffler. The current car's exhaust has some sort of resonator in the middle already, so I'll probably keep that. Below is what I'm looking at...

Cat...
Magnaflow 94105 (universal fit 2.25" in and out, bout 9" long)

Muffler...
Dynomax Super Turbo 17732 (2.25" in and out offset, bout 18" long)
or
Magnaflow 11265 (2.25" in and out offset, bout 24" long)

My biggest question is.... will either of those mufflers help with the totally abnoxious fart can sound I have now? I'd prefer quieter if possible. The sound clip of the super turbo over at r3vlimited sounded good in theory... but may even be a bit buzzy for me. Maybe the cat will reduce some noise too. Also, how much space to I actually have to work with for a muffler? Are those two mufflers too big? Small? I plan to have a muffler shop weld it all up for me. Oh and as far as the inlet / outlet... offset? Centered? Does it matter?

Any suggestions are appreciated!

I want this "horsepower" gone! :p

4banger · « **Reply #1 on:** February 01, 2010, 08:19:59 PM »

i built my system on my 4door. stepped tube header. 2 1/2in collector. 2 1/2 stainless back to a high flow ceramic core bullet cat. 12in resonator to a 2 1/2in & out flowmaster. first version was a one chamber. changed that for a 2 chamber and it lost that shitty ricerocket rasp. im happy with it. bigger resonator will help with the rasp.

BlueBMW · « **Reply #2 on:** February 01, 2010, 08:31:15 PM »

Thats what I hate most is the rasp noise... too much soy sauce for me.

4banger · « **Reply #3 on:** February 01, 2010, 08:38:08 PM »

it was just raspy in the midrange. above 5500 it sounded great. plus the idle was wicked with the mild cams im running.

BlueBMW · « **Reply #4 on:** February 01, 2010, 08:40:28 PM »

Top rpms, even that fart can sounds good. M42 luv....

4banger · « **Reply #5 on:** February 01, 2010, 08:45:18 PM »

i used a vibrant performance cat. offeres zero sound supression lol

http://vibrantperformance.com/catalog/product_info.php?cPath=1022_1035_1063_1112&products_id=853 without the sheild. my entire exhaust is wrapped in header wrap

BlueBMW · « **Reply #6 on:** February 01, 2010, 08:54:31 PM »

Did going 2.5" make much difference from 2.25"?

4banger · « **Reply #7 on:** February 01, 2010, 09:16:48 PM »

seems to rev more freely. but that could have been the stuffed up stock cat and cheap parts store $15 muffler.

BlueBMW · « **Reply #8 on:** February 01, 2010, 09:26:35 PM »

Mine seems to rev good right now, it just sounds awful! You cant hear yourself think on the highway

4banger · « **Reply #9 on:** February 01, 2010, 09:34:38 PM »

i ran it on just the header and cat to the welding supply to get a new torch for my tig and it was deafening. sounded bad ass at idle tho. sure did get some looks. 318 4door steelies with no hubcaps just the drivers seat and bent up hood and fender lol a few of the ricer boys got ballsy on the highway and got their feelings hurt ha. its all back together now. i was putting new carpet and seats in it at the time i got a hair up my ass to do the exhaust.

BlueBMW · « **Reply #10 on:** February 01, 2010, 09:46:58 PM »

Love the sig btw. I think that's why I like the M42 over the M20 so much.

4banger · « **Reply #11 on:** February 01, 2010, 09:59:40 PM »

me too. they are underrated engines.

BlueBMW · « **Reply #12 on:** February 01, 2010, 10:12:28 PM »

The guy I bought the 318is from has bought two 6 cylinder e30s since selling me this one. He was trying to sell the 318 and buy a cheaper fixer upper e30 and use the extra money to pay some bills or something. He put a new head on the first one, but just couldn't seem to get it running right. Then he bought the second one, a good running eta, but it seems like its leaking oil from the headgasket. After messing with the one and then the other he told me he kind of wished he kept his 318is. I think his exact words were... "I'm sick of M20s..." Makes me feel kind of bad taking his nice car from him...

4banger · « **Reply #13 on:** February 01, 2010, 10:23:40 PM »

i bought my DD. 91 318i from a couple of mexicans at a used ar lot in northern va. after taxes and title it was $900 out the door. this was 7 years ago. since then ive aquired a 91 IS another 318i a 325i 2door a 77 2002 and as of last nite a 85 318i 2 door for my m10 turbo build.

BlueBMW · « **Reply #14 on:** February 02, 2010, 06:34:14 AM »

Quite a collection!