Thread: D1 exhuast size?

anything over 2 and less than 3 is fine,,
more important is the ground clearance in general and in particular around the y piece,,
run a resonator up the back,, be prepared to change it if necessary, wrap the extractors in heat tape.

It'll make a nice noise,,

will it go better and save you money??

I run a 2 1/4 pipe with one straight through muffler in the middle and a hotdog on the end. Sounds excellent. Ran it for a while without the hotdog on the end but it was to droney/farty above 3000rpm.

I've got a 3 inch on my Tdi300 spools up quicker, sounds alot better to now

The 3.9 is running a 20" x 2.5" Lukey Ultraflo up front and a 14" x 2.5" Ultraflo at the rear.
Do find it sounds a bit too much like a 253 once it starts revving, very clacky out the back, but in cab doesnt sound too bad.
My diagnosis is there isnt enough can volume in the Ultraflo's as they are straight thru but full of stainless and glass packing. Tends to take away all that lovely deep thundery note they had from standard. All I wanted to do was increase the thunder without all the lightning crack!!

I've just pulled a 2.25" with one central muffler from my ute (3.5).

Freakin loud!

Thinking back to my ol VW, I'm pretty sure its Hot Dog mufflers that bring out that really deep tone.

I tried both sizes, the bigger you go the more it can scrape if going off road.

Neither did anything at all for performance, not even a mandrel extractor set, quite the opposite actually.

So travel careful down that path, I even went stainless and gained nothing bar a nice sound that did get to be a bit annoying on long trips.


So go for what you feel suits you best.

If its sound you are after, just take out a muffler and put straight pipe in, cheapest and when you are sick of it its easy to replace.


Just a thought.