Need Some Help

Just picked up an '05 m3 vert. It's my first BMW so I don't know too much about them, just what I've read on the forums. I just threw a BMC filter in along with an aftermarket elbow and intake scoops. I've seen some pretty good feedback and gains from the ebay headers so I'm giving them a shot, should be here any day. So I just had a couple of questions in regards to the exhaust....

1)Cat back looks like the biggest benefits are weight reduction and a different exhaust note, but I don't want to be too loud. Would the combo of headers + cat back be that much more beneficial or can I get away with just the headers?
1)Will the headers give me a check engine? If so would any software take care of that
3)I've read so many mixed reviews on software, some saying don't waste your time and others saying it's a must... Seems like it helps if you've got a few mods going though? Any recommendations?

Any other suggestions on mods are welcome! I'm not looking to do anything too major, just trying to make up for the loss in performance going from a hardtop to the convertible.

+1

Anybody?

1)Cat back looks like the biggest benefits are weight reduction and a different exhaust note, but I don't want to be too loud. Would the combo of headers + cat back be that much more beneficial or can I get away with just the headers?

Muffler first, then get into headers and cats, no point of keeping OEM muffler and putting in ebay headers and aftermarket cats.
You can still get a really light performance muffler that is no too loud.

1)Will the headers give me a check engine?

The ebay headers will give you a CEL, you dont need a software flash to fix this, you need man-made looped over bypass sensors which trick your computer to thinking everything is good. You can get it this unit off ebay for less than 50 bucks i believe.

3)I've read so many mixed reviews on software, some saying don't waste your time and others saying it's a must... Seems like it helps if you've got a few mods going though?

Once you get the header, cats, (x/s pipes), muffler, intake, it might help a little to get a software upgrade (say conforti), but the gain due to software is not much for the amount of money you need to spend on software.
Just reset your computer once you have everything in and the cmputer will adjust itself to the new hardware.

GL

Thanks for the reply. I've got a tight budget so I was planning on running just the headers to the stock section 1 and 2 (w/o cats in other words) and I'll pick up a muffler system. Recommended? How do I go about resetting the computer? And what do I search for the bypass sensors, can't seem to find them?

UUC seems to be popular here for exhaust. Best bang for the buck IMO is muffler delete. I would try that 1st. It's cheap. As far as to "tricking" your O2's, Ya gotta do a search cuz I'm not too familiar with that procedure to keep the SES off. I know there others out there who have succeded in this area. Chas

Muffler delete is ok on the regular 3 series, but on a M3, it sounds bad. Go with a Magnaflow, Remus or Dinan muffler if you want a little louder than stock. Go with Agency Power, Eiseman, Groupe M, SuperSprint, and several others if you want considerably louder than stock. I would recommend you go to car meets and try to listen to other M3's that have aftermarket exhausts installed to get an idea. With the weather getting better and the car show season getting underway, you'll be able to audition a lot of exhausts.

I just came across the "Rasp Terminator" with high flows to avoid the CEL. It's supposed to be emissions compliant which would be great living in CA and all. Says for use with long tubes though.... is there long and shorts for the m3 or would the ebay headers bolt up???

google can answer almost every question to every problem out there.

Here is a link to a thread that a member wrote up when he did his ebay header install along with tricking the o2 sensor so you dont get the CEL light.

http://forum.e46fanatics.com/showthread.php?t=743684

Also, if you're tight on budget, although the ebay header comes to be less than 100 bucks shipped to your door, the installation cost is 300-500 depending on the shop. If you're doing it yourself, it wont be simple and easy and you need the right tools.

However, overall, since you just picked up your vert, start with the more casual stuff then go into more complex mods.

If i were you, i'd first think of getting a muffler, then slowly overtime get the headers, midpipes and so forth.

The thing with modding Ms is that you have to approach it the right way, take your time and do mods one by one over a longer time period. This allows your head some time to visually and mentally understand all available options and pros/cons of a thought out mod before you pull the trigger on any of them.

Never the less, dont rush into anything take it step by step and good luck!

I know it's been a while but I ended up going with a full Magnaflow catback system and I'm very happy with how it turned out, fitment and sound (and I got a great deal on it ). I also added a BMC filter, Macht Schnell intake elbow and RPI scoops behind the grill. So here's the dilemma, I've got my ebay headers sitting here... if I put them on I would probably go catless b/c I would have to get it smogged illegally with the headers either way and there isn't really room to weld in aftermarket cats in the section 1, it's a pretty tight fit. If I were to go that route, I have to use the o2 simulators to prevent the CEL. But do I really want to get into all this.... not really. Any ideas on squeezing some more power out of the car without getting too complicated???

I got a vert like you and im new to this too.
Ive heard pulleys like from evosports one will get you some more power. and at your place i would give the conforti software a shot and its not expensive i think.
I have the same mods like you in my head...actually it is the easiest everyone is getting + i thought about getting a UUC shorf shifter, just for the feeling of the shifts.

Did you get the full magnaflow exhaust system? a deal...how much?

The pulleys and software seem to be next in line, and if i do decide to add the headers later on... you're supposed to be able to upgrade software to the shark injector via usb from your computer. thanks for the input! under $900 shipped to my door. custom-performance . net

it seems we are going the same route man
i would love to hear how your car sounds with the new exhaust...if you have any videos point it to me plz.
and did you notice any difference in the performance?
by the way did you try changing the spark plugs/air filter/fuel filter? it did a change on mine

PS: I like custom-performance . net performance packages...not bad (Software + Afe stage 2 + pulleys + magnaflow catback)

Originally Posted by chlippo

it seems we are going the same route man
i would love to hear how your car sounds with the new exhaust...if you have any videos point it to me plz.
and did you notice any difference in the performance?
by the way did you try changing the spark plugs/air filter/fuel filter? it did a change on mine

PS: I like custom-performance . net performance packages...not bad (Software + Afe stage 2 + pulleys + magnaflow catback)

Haven't checked this thread in a while, sorry.... If you're still in the market for the exhaust, I'll try and get a video clip of it within the next couple days. Those performance packages set you up pretty nicely, definitely the way to go to get some extra power with modest mods. I dropped in the BMC filter so I'll look into the fuel filter and spark plugs. Thanks