Exhaust centre box delete, too loud?

[chu346]

My centre box is rattling and was thinking about replacing it with a straight pipe, would it be too loud?

[he30]

I have no center box and its fine for me gets a bit droony on a long run but livable

[StuBeeDoo]

Will probably make a small difference, but wouldn't be as bad as taking out the rear box and leaving the centre one.

[TRANSPORTER]

Yep same here, some berk of a previous owner decided to lose the centre box and totally hashed the home made pipe work in its place, its a bit loud on the pulling away and a tad droning on long runs but I can live with it for now although when the otherhalf gets in it from her E36 which is whisper quiet she hates it just waiting for local scrappy to have an E30 in so I can rob bits off thatto fit to mine or hold in me garage for future use

[Ziggy]

Not had a centre box for a couple of years & it's not too loud - my supersprint rear box is probably quieter than a standard one would be though...

[ric325i]

depends what you like. i say bin the middle box.

but then again my old 325i had the best noise ever with middle box and back box. would not have wanted anything different.

if the back box is good then......

[burrows]

Is there any gain in performance from better flow or anythin like that.

[georgen]

My old sport had no middle box and sounded great !! Droned a bit on long runs, but I felt the noise suited the car..

[insertnamehere]

So no centre box would be OK for MoT purposes???

Think I might try this then, and just keep my new system as a spare...

[markdemon]

if its not there dude they cant test it = cant fail it

[HenryM3]

I had no center box on my S50 B32 conversion and made 317 bhp and 234 torque at Ray West Tuning and he advised me to fit a center box as I was losing back pressure. Had one made at torque techniques and then made 330 bhp and 260 torque. Read into that what you want.

[suzie650]

And depending on the pipe you fit, you may get unpleasant harmonics...
On my daily driver (non-bmw), the previous owner fitted a straight through middle section (well, and a remus backbox) and the harmonics from the middle section make the whole car shake and rattle between 2800 and 3400rpm... More annoying, it keeps blowing the backbox...
Can't be asked to fix it, though.

[Brianmoooore]

So no centre box would be OK for MoT purposes???

Think I might try this then, and just keep my new system as a spare...

Depends on the mood the tester is in. This is the relevant text from reasons for rejection: b. a silencer in such condition, or of such a type, that the noise emitted from the vehicle is clearly unreasonably above the level expected from a similar vehicle with a silencer in average condition.

[StuBeeDoo]

Thanks for that quote Brian. I've been trying to find the text regarding silencer effectiveness for another thread.

[Weeman]

Hi Guys, I smashed the cat to bits the other week on the is, so now it has just the empty casing, doubled the noise the car made with the rear powersprint group N pipe, Has a metallic resonance to it now, to be fair it dounds like its swalloed a moped and its evil LOl Needs a straight pipe in there to damp it down a little, few vids here, sorry for the crap quality guys, Plus its an I.S, but it gives you an idea of how loud it is


http://s24.photobucket.com/albums/c8/du ... o001-1.flv

http://s24.photobucket.com/albums/c8/du ... deo006.flv

[AlexBaur325]

Is there any gain in performance from better flow or anythin like that.
_________________

im sure BMW made the system the way they made it for a reason...not being fersecious, just saying

[Ziggy]

As above; I'd be extremely surprised to see any performance gains from removing a silencer, or fitting any aftermarket exhaust system (unless coupled with a better manifold etc). I'd be interested to see how a standard system compared on my car, but methinks I might struggle to get it to fit!