tangalife 1 Report post Posted February 12, 2013 Trying to figure out what way to go for my 540i. I have been told that a catylac(sp) converter removal can increase HP and give it a good note. Also heard of others deleting the resonator or even just one muffler. However I cant find anything on google (nz searches) to help with this. I am mostly after a better sound more than performance and dont have a huge budget either Quote Share this post Link to post Share on other sites
Allanw 1072 Report post Posted February 12, 2013 Trying to figure out what way to go for my 540i. I have been told that a catylac(sp) converter removal can increase HP and give it a good note. Also heard of others deleting the resonator or even just one muffler. However I cant find anything on google (nz searches) to help with this. I am mostly after a better sound more than performance and dont have a huge budget either Have you got the twin rear mufflers side by side behind the bumper? (only on has an exit, the other is just a chamber). If so, drag out the hole saw and make a hole in the empty chamber - mate did it on his touring and it sounds great when being caned, but never obtrusive. Has a nice rumble down low too. If you wanted, you can weld a pipe from the hole into the existing tail pipe. Quote Share this post Link to post Share on other sites
BreakMyWindow 1878 Report post Posted February 12, 2013 Remove the 2 rear mufflers, and replace with 2.75" pipe. Opens up the V8 burble niceley. You shouldnt fail a wof either - i've been through about 8 so far. Quote Share this post Link to post Share on other sites
tangalife 1 Report post Posted February 13, 2013 yep have the two muffler design. just putting a hole in there sounds a bit hori, but if you say it works?? breakmywindow, got any vids of your car running with that? Quote Share this post Link to post Share on other sites
hybrid 1044 Report post Posted February 13, 2013 Removing the cats and not either retuning or reflashing with non cat DME software will cause over fueling and there for less power as far as the DME is concerned. The DME gets pretty confused as the difference between pre and post cat sensors is the same and will never be different. Quote Share this post Link to post Share on other sites
Michael. 2313 Report post Posted February 13, 2013 When you say your budget is not huge, what do you intend on spending up to? Removing the cats and not either retuning or reflashing with non cat DME software will cause over fueling and there for less power as far as the DME is concerned. The DME gets pretty confused as the difference between pre and post cat sensors is the same and will never be different. Yes, this must be taken into consideration when tweaking the exhaust. Quote Share this post Link to post Share on other sites
tangalife 1 Report post Posted February 13, 2013 might be best for a muffler chop then. budget... at this stage, probably $500 which I doubt would get me far. I still want to upgrade my sound system and keep some money aside for any repairs as I've just bought the car Quote Share this post Link to post Share on other sites
Tristan 338 Report post Posted February 14, 2013 might be best for a muffler chop then. budget... at this stage, probably $500 which I doubt would get me far. I still want to upgrade my sound system and keep some money aside for any repairs as I've just bought the car It comes down to priorities. I wouldn't go drilling holes in the back box of a car I'd just bought... Like you said, pretty hori! I went to Woolfe Mufflers on Dominion Rd, Auckland (don't know where you're based) They did my E39 exhaust for $400, incl. twin tips I'm sure you could get change out for $500 for something that sounds nice. How badly do you need a sound upgrade? How badly do you want the V8 rumble? Do these come before any repairs that may be needed? Quote Share this post Link to post Share on other sites
jeffbebe 1560 Report post Posted February 14, 2013 Removing the cats and not either retuning or reflashing with non cat DME software will cause over fueling and there for less power as far as the DME is concerned. The DME gets pretty confused as the difference between pre and post cat sensors is the same and will never be different. Not planning to do anything to my exhaust but keen to learn more about this... Got time to elaborate, Josh? Quote Share this post Link to post Share on other sites
