RexNuts Subaru Forums

Hi guys
Like many I've considered a twin scroll conversion. I've been reading treads here and there on the subject and have noticed a particular style of dump/down pipe is required. However when I search for these pipes many are just bell mouth style. Is there any actual difference between these and regular bell mouth dump/down pipes?

The shape of the mouth is different where the dump bolts up to the turbo, also different bolt pattern and no need for a splitter as its built into the turbo.

Main difference is the flange. If you already have a 3 inch dump, you can buy a flange & mod yours to suit, buy a pre fabbed half dump & cut & weld, of buy a full dump that matches up with your cat/mid pipe.

Splitter is up to you.

Thanks guys. Does anyone sell a complete twin scroll dump pipe? I would prefer one piece over a cut and weld.

TCP was talking about it on the other forum. Honestly with the 2.5L its probably not worth going to TS unless you are goiing for a big rotated setup on a built motor, they are great for the 2.0L though.

Your probably right mate
I've been considering a 1.5 scroll, aka split pulse header. Basically a twin scroll header with a single collector up pipe running into a single scroll turbo.
I'm chasing quicker spool like everyone else lol

I'd probably go for one of those new big 16g turbos with billet wheel from PSR, would be nice with 2.5L, equal length headers give good results but a lot of aftermarket headers crack.