HDi debackboxed

[aaron_one]

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?

[JackLewis_Dturbo]

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...

[Oil-burner]

Either or mate, that's all I did in my dt.
As long as its got at least 1 box your legal!

[aaron_one]

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?

[Chris_90]

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


And de-back boxed like this, I noticed a slight bit of difference when i did this the noise level did go up slightly

[Poodle]

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.

[aaron_one]

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?

[Poodle]

...As long as you have one box in your system it's legal...

[aaron_one]

Oh I was thinking legal as in getting pulled over haha I get it now

[Poodle]

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.