big525i

neither of those websites work for me bimmerbrakes says it has no products for any cars and O2sims.com doesn't work directs me somewhere else

cleung

sorry I gave the wrong website addy
try this
http://www.o2simulator.com/

I contacted bimmerbrakes through the e46fanatics forum, the owners name is Anthony. I used to have a e46 so I still have a username over there. I go there once in a while still for different mods (vendors there sell some things for much less). There is also tons of info on headers over there, which is where I did most of my research before deciding to try it out.

big525i

k thanks

cleung

Ok guys a little update. So after the headers I was getting a lot of rasp which I thought I could live with but it was starting to drive me crazy. I ended up contemplating a number of options but couldn't really find a good answer from anyone. I thought about a x-pipe in the mid-section just after the headers which should quiet down the rasp but keep the exhaust at the same volume. Another thought was to put a y-pipe in right after the headers and then go to a single 3 inch pipe all the way back to the muffler, this would delete the factory y-resonator and I would then install a resonator in the 3 inch pipe somewhere. The other option which was the easiest was to install 2 resonators in the mid-section, this would quiet the rasp and the exhaust tone but I didn't think I had enough room to fit 2 resonators in side by side.

So today I went the the muffler shop and they suggested the dual resonator solution and said they could make it fit. So what ended up happening was they were able to install 2 straight through resonators, they were able to fit the resonators in where the oe vibration dampener is located. They had to cut the dampener out to install the resonators and one of the resonators are offset.

So 95% of the rasp is now gone, however the exhaust is quite quiet now. I wasn't really wanting it to be so quiet but the good part is there is now rasp now. Hopefully after a few days of driving the resonators will be broken in and I'll get some of the volume back. All in all for the little cost of the resonators I'm fairly happy with the results.

Jonsmilez

This was an informative read..

When you say "rasp", are you referring to drone, particularly on the highway?

And after the header install did you notice any power gain?
What was your purpose behind install? Noise? Power gain? Light weight?

I have the same, '04 530i M54, and I was considering the same mod, but I'm glad you took the step first to be the guinneapig

What's your final verdict on the headers install?

Thanks in advance

big525i

sounds really good idk if i would of went wit afterwards i think it sounds too good to quite it down

cleung

So the verdict is, definite power gain noticed especially at WOT on the highway. The OE headers/cats are very restrictive on our cars.

When I say rasp I'm referring to an almost metal like rattling noise that comes from the midpipes. I'm told this is very common after exhaust mods because its now so free flowing. The car did drone as well around 2,500rpm so not really too bad on the highway.

After the resonators the car is very quiet, although I had a chance to drive around quite a bit last night and and I think I have broken in the resonators a bit so the volume is back up a little, but still very quiet. In hind sight I think I would have preferred to try an x-pipe crossover in the midsection to get rid of the rasp but keep the volume.

I will post another vid on the weekend after I get a few more miles on the resonators, hopefully it will sound better.

And you're welcome, about being the guinea pig.

Jonsmilez

Thanks for the write up. I look forward to the video

cleung

more vids these are with the resonators, let me know what you guys think.
headers with resonators 1
headers with resonators 2

Jonsmilez

Sounds nice!!
Seem quiet at low rpm and deep at higher rpm!!