EK Exhaust Piping Sizes

[TranceZiggy]

Hey guys,

Yes another exhaust question.. Search can't really give me an answer to my specific situation.

Anyway, I'm currently running an axle back twin loop (2.5" inlet). While its got the right tone, it's probably not as 'smooth' as it could be with a complete system. I'd also like it a little bit louder, plus the increase in responsiveness that the headers produce would be nice ;)

So, I was thinking of getting some headers & everything else inbetween to make a complete setup. Question is, would the differing sizes work well together?

Example:

Headers (2") > Cat (2.25") > Back Pipe (2.25") > Twin Loop (2.5")

Would that be allowing the exhaust gasses to flow too freely? Not enough back pressure? (Please no arguments about whether back pressure is a myth or not - the theory makes sense to me). Or should I stick with 2" throughout til the twin loop?

Oh, an it's an EK1, so running a D16Y4 with no plans for swaps or turbo. (If I happen to make plans for either of those, it would be because I landed a ton of cash and therefore have the cash to upgrade the exhaust again to suit ;)

Cheers for any input :)

[dougie_504]

Yeah that's fine mate, as long as you're going from equal size to equal size, or smaller to larger. Then it won't bottleneck.

[TranceZiggy]

Cool, cheers man. That's what I thought was the case, cause I was originally going to install headers (2") & cat-back (2.25") but then it occurred to me that there would be a 1.75" bottleneck right in the middle (the Cat), so I would have to also replace that to get proper flow-through.

Edit: Also, opinions on aftermarket Cats? Ebay? Or should I get a Magnaflow from my installer?

[99em1]

Hey mate I say go magnaflow because it's worth ur bucks and it gives a better flow. I've got one fitted in my car ;)

[CRXDEL501]

1+ Magnaflow

Keep away from eBay exhausts