I'm thinking of getting rid of my standard backbox with the downwards tip as it looks crap. I want to swap with something and heard if you just weld a piece of pipe on instead of the backbox it'll give it a performance gain, is this true?
I've heard of the middle box conversion but I'm just looking at all options before I decide really.
Thanks?
you get better flow with no backbox for better gains....
IMO dont bother with the middle box conversion unless you dont like a noisy car! lol even so its not that loud...
Either or mate, that's all I did in my dt.
As long as its got at least 1 box your legal!
Cheers guys, so as long as I have a middle box I'm still legal even if its decat and debackboxed?
Think ill go for the debackbox I need a bit of noise in my life!
Will the gain be noticeable if I have decat and stage 1 map?
I just emptied my cat out like this with this the noise level defo went up and i could defo notice the turbo spool quicker
![[Image: 306new65.jpg]](http://i552.photobucket.com/albums/jj332/mazda_323f/306new65.jpg)
And de-back boxed like this, I noticed a slight bit of difference when i did this the noise level did go up slightly
![[Image: 306new53.jpg]](http://i552.photobucket.com/albums/jj332/mazda_323f/306new53.jpg)
As long as you have one box in your system it's legal, the cat isn't currently required for MOT purposes.
You should notice the gains, the turbo will spool a little earlier thanks to the lower restriction from the exhaust and it will be happier to rev.
I'm going to get rid of the backbox sometime in the next week or so then! Do you need a backbox to pass an MOT?
(19-11-2012, 02:22 PM)Poodle Wrote: [ -> ]...As long as you have one box in your system it's legal...
Oh I was thinking legal as in getting pulled over haha I get it now
Technically it should be the same thing, if we're talking purely about vehicle defects. Although, what gets you pulled is often 90% discretion of the challenging officer as far as i can tell.
