Centre crossflow box or dual backbox delete
 

Afternoon Chaps,

Total noob here although I've been stalking the forum for a while :)

I took delivery of an 58 plate A8L 4.2tdi in early Nov and I'm looking to chav it up a bit (sorry).

I love the performance and engine growl but its not quite loud enough.

I've read a few threads re box deletion. If given the choice what would the best option be - centre crossflow box delete or dual back box?

Also in the forum's experience, would there be any adverse effect in terms of performance?

Thanks in advance!

I've looked into this at some depth and the conclusion is no adverse affects at al, you'll just be happier and have a nice exhaust note.

Il be going on my 3.0tdi a complete dpf removal, cat removal and strait pipe with the likely hood of a possible box put back in if its to much.

But when I'm cruising around it sits at 1500rpm if that so the noise won't be intrusive at all until you mash the throttle some.

I may possibly leave the cats in as it may upset a few things but that's the only part I haven't researched fully.

I may go to amd Essex in Thurrock and use it all done and mapped in house if they do dpf delete software.

If I was you I'd loose everything from the cat back. The dpf and cats will heavily restrict flow and noise. If you can perhaps remove the exhaust as its in sections anyways.

Im looking to do something similar with mine. Dpf and cat are gonna go, but i dont want lots of turbo whistle and a crap noise.

I think they could sound proper dirty as they are such a low rpm engine even for a diesel (4.5k redline, scoots along under 2.5k most part)

Its just getting the right combo!

Yeah I'd keep one box then or have a box put in a custom system. You'll always get whistle and that diesel turbo noise but with a v6 twange.

Just search YouTube for 3.0tdi Audi strait pipe. Then you'll see what others have done.

I had a crossflow delete on my 4.2 V8 FSi and I'm really happy with it. Changed over to straight through powerflow pipework for just £180. I put this on a thread only a few weeks ago with pictures. Do a search in teh forum and you'll find it.

No adverse additional noise at higher speeds, just a nice raspy roar, especially between 2-3k and on cold idle.

Deciding whether to reduce the size of the back boxes to lower the note a bit but at the moment I'm happy with it, money well spent.