rishi Posted September 11, 2008 Report Share Posted September 11, 2008 he cb i dont think we can do it, i havent had a chance 2 haev a look but we only got 1 exasut pipe, so by looking at where these guys have the valve thingy , wed essentially have no exaust when it was closed ( i think since they have a twin pipe one is closed) so looks unliekly Link to comment Share on other sites More sharing options...
cbv8 Posted September 11, 2008 Report Share Posted September 11, 2008 he cb i dont think we can do it, i havent had a chance 2 haev a look but we only got 1 exasut pipe, so by looking at where these guys have the valve thingy , wed essentially have no exaust when it was closed ( i think since they have a twin pipe one is closed) so looks unliekly I agree mate it aint for us BUT i suppose we could chuck the rear box away and replace with straight through pipe with a nice chrome tailpipe and if we spent money god forbid We could also buy one of those sports cats to replace our original restrictive one then that would i think yeild little more power and give us a throatier sounding exhaust Link to comment Share on other sites More sharing options...
rishi Posted September 11, 2008 Report Share Posted September 11, 2008 yeh quad exaust all the way lol, or the 335 one, oh and engine conversion lol Link to comment Share on other sites More sharing options...
simonlpearce Posted September 11, 2008 Report Share Posted September 11, 2008 Aha, makes sense now. Mine was open when i had a look so i assumed it had rusted that way, now you say it is supposed to be i will go about plugging that tube. Just have to take my work desk apart to find me a suitable screw. Link to comment Share on other sites More sharing options...
Dicky Posted September 11, 2008 Report Share Posted September 11, 2008 Jonny see what you have started everyone is out there following your DIY guide Glad it has helped members already and new members to come Link to comment Share on other sites More sharing options...
DaveDunlop Posted September 11, 2008 Report Share Posted September 11, 2008 yeh i did this mod at work today, took a work car home so didnt get to drive but look forward to hearing the results tomoro. Link to comment Share on other sites More sharing options...
Scuba Posted September 14, 2008 Report Share Posted September 14, 2008 LEGEND! What a great find. I read this last night around 3am and fancied giving it a try. Just remembed about it 15mins ago, so went out and had a look. My valve was rusted shut so I grabbed a flat head screwdriver and small mallot. I gently tapped around the right hand side until I got a bit of movement. I then got a thin metal bar and prised it open fully. I dont think I'll need to clog up the vaccum hose and it seem pretty hard to move the valve. The differce in sound is really good, seems to be more noticable at slower speeds. One thing I did notice was a bit of black suit was coming out when revving it up a bit. Most likely a build up since it had been rusted shut. I immagine it was dissapear after a few mile of driving. Anyway, top class find and would definetly reccommend it to anyone thing about trying it, 10minuite job. Cheers Link to comment Share on other sites More sharing options...
SJD Posted September 14, 2008 Report Share Posted September 14, 2008 Nice one Scuba. Welcome to the forum. Link to comment Share on other sites More sharing options...
SJD Posted September 15, 2008 Report Share Posted September 15, 2008 For those wondering what on earth the exhaust flap is there for, I came across this: Thank you for your email to BMW Customer Information. We can advise that the exhaust flaps adjust at differing engine speeds in order to make the most effective use of the exhaust silencer. When the vehicle is running at idle or at low RPM, the flap ensures that the exhaust gases use as much of the silencer's volume as possible, keeping exhaust noise down, e.g. when you're in slow traffic or driving in high gear. Whereas when the vehicle is running at high RPM, the exhaust flow characteristics are adjusted by the flap to give the exhaust gases a more direct route through the silencer, thus using less of its volume. This also has the effect of allowing the engine to rev more freely as there is less restriction on the exhaust flow. The primary reason for the flap is to make the most effective use of the exhaust silencer volume at differing engine speeds. We trust this information is of some assistance to you but if we can help you further at any time, please do contact a member of the BMW Customer Information Team. Link to comment Share on other sites More sharing options...
bigbaz Posted September 15, 2008 Report Share Posted September 15, 2008 My understanding is that the butterfly valve is there to alter the backpressure through the silencer at low revs to increase torque, a bit like the EXUP valve in the exhausts of Yamaha motorcycles. It is there for more than just to make the car quieter at low revs. Having said that, there are a lot of aftermarket silencers out there that don't have any flap valves fitted and no one seems to complain about the performance. Donna, where's me golf clubs???????????????????????????? Link to comment Share on other sites More sharing options...
simonlpearce Posted September 22, 2008 Report Share Posted September 22, 2008 Hi guys Just wanted to thank Dave for showing me where to find the hose thing which needed plugging, got it sorted at UBMWS. At first i thought it was a load of pap but after driving a few hours home it really does make a difference. It is most noticable say when you in 6th travelling around 55MPH, car should be at roughly 2k revs and you should hear a nice and suttle deep bellowing sound. This soon goes and your back to normal as you pull away. Great mod worth doing. Link to comment Share on other sites More sharing options...
DaveDunlop Posted September 22, 2008 Report Share Posted September 22, 2008 Hi guys Just wanted to thank Dave for showing me where to find the hose thing which needed plugging, got it sorted at UBMWS. At first i thought it was a load of pap but after driving a few hours home it really does make a difference. It is most noticable say when you in 6th travelling around 55MPH, car should be at roughly 2k revs and you should hear a nice and suttle deep bellowing sound. This soon goes and your back to normal as you pull away. Great mod worth doing. glad you noticed it mate, as i say i wasnt sure how much difference it made as i did it when i fitted my air filter. and its free so you cant go wrong!! Link to comment Share on other sites More sharing options...
Jonny Posted September 25, 2008 Author Report Share Posted September 25, 2008 So glad this is working for people, and making a difference!! Never thought it was going to be such a hit lol Link to comment Share on other sites More sharing options...
Jonny Posted September 30, 2008 Author Report Share Posted September 30, 2008 Also a quick thanks to dicky and Sam for arranging this into a proper DIY so I didnt have to Link to comment Share on other sites More sharing options...
clubsport_chris Posted September 30, 2008 Report Share Posted September 30, 2008 I tried it it didn't seem to make any difference to mine. Link to comment Share on other sites More sharing options...
SJD Posted October 3, 2008 Report Share Posted October 3, 2008 I tried it it didn't seem to make any difference to mine. Was yours shutting in the first place? Some get stuck open. Maybe it is the fact that you get so much more noise in due to the lack of rear 3/4's sound deadening with the C/S. I just told another C/S owner to view this thread as well! Link to comment Share on other sites More sharing options...
clubsport_chris Posted October 3, 2008 Report Share Posted October 3, 2008 Yeah i made sure the flap was working before i took the pipe of. Link to comment Share on other sites More sharing options...
DaveDunlop Posted October 3, 2008 Report Share Posted October 3, 2008 im unsure as i did it the same time i fitted my air filter so wasnt sure what the new great noise is lol. maybe its a bit of the placebo effect aswel?? Link to comment Share on other sites More sharing options...
Jamee Posted October 4, 2008 Report Share Posted October 4, 2008 Looked at mine yestaerday and mine is stuck closed solid!!!...if it ever stops raining here, i will get my crowbar and sledge out and open it up. Link to comment Share on other sites More sharing options...
Dark_Knight Posted October 13, 2008 Report Share Posted October 13, 2008 will it work on a 318 Ci, with single exit exhaust? Link to comment Share on other sites More sharing options...
Jonny Posted October 13, 2008 Author Report Share Posted October 13, 2008 Looked at mine yestaerday and mine is stuck closed solid!!!...if it ever stops raining here, i will get my crowbar and sledge out and open it up. Jamee, did you manage to get it open alright? Mine took quite a bit of force. will it work on a 318 Ci, with single exit exhaust? Sorry Prop, This is only for twin exhaust cars, as the valve is used to shut one of them off at low revs to minimize exhaust noise. Link to comment Share on other sites More sharing options...
Dirty Tool Posted October 13, 2008 Report Share Posted October 13, 2008 Tried doing mine yesterday...and it was shut solid! Took a hammer/screwdriver to it but to no avail...I was tapping it on the right hand side of the flap - is this the correct side? Cheers. Link to comment Share on other sites More sharing options...
Jonny Posted October 13, 2008 Author Report Share Posted October 13, 2008 Tried doing mine yesterday...and it was shut solid! Took a hammer/screwdriver to it but to no avail...I was tapping it on the right hand side of the flap - is this the correct side? Cheers. Dirty, At work at the mo so cant see the picture i posted which shows which way it turns, but I'm pretty sure your spot on tapping the right hand side. Try using some WD40 on and around the valve or some other lubricant and remember it will take some very heavy blows to dislodge depending on how bad it is. I ending up using a tyre mounter (like a small crowbar) and had to hit the end of it with a hammer to get it to go anywhere. HTH and good luck! Link to comment Share on other sites More sharing options...
Jamee Posted October 13, 2008 Report Share Posted October 13, 2008 Same here, had to use a straight crowbar, and just bang it open, also did the golf tee mod on the pipe. As it was so stiff, it has wedged open now and sounds soo much better, loads of black soot/carbon came out once revved tho for the 1st time. Bang it on the right hand side. Link to comment Share on other sites More sharing options...
Jonny Posted October 13, 2008 Author Report Share Posted October 13, 2008 Same here, had to use a straight crowbar, and just bang it open, also did the golf tee mod on the pipe. As it was so stiff, it has wedged open now and sounds soo much better, loads of black soot/carbon came out once revved tho for the 1st time. Bang it on the right hand side. It is suprising how much better the stock exhaust can sound Not so gut renching anymore when your with mates with crapper cars but better sounding exhausts! (They gotta have something under the hood to back it up though lol ) Link to comment Share on other sites More sharing options...
