chrisdicko

iTrader: (21)

Might sound a weird question, but.....

I bought my car with mods already on, and all the receipts etc.

When the owner got the exhaust done, everything seemed to be changed except the Headers. It says "Full de-catted stainless exhaust system, inc up and down pipe"

So, what's the point in just changing the up-pipe without the headers? I'm not too clued up, so this may be a stupid question!!!

AshBurton wrx

If you change the headers you can loose the burble

chrisdicko

iTrader: (21)

??

Only if you get equal length ones.

I mean, when I bought the car it had it's up pipe changed. But the headers are still OE. Just wondered the benefits of doing this........

powerwrx

iTrader: (11)

decatting the uppipe allows a mapper to add more boost as far as im aware, upping the boost while still having the standard cat pipe can make the cat break up therefor knackering your turbo and probably other parts too

Shmerman

iTrader: (14)

The cats create back pressure therefore increasing boost will not necessarily increase power output if the cat is still in place.

with reguards decating the uppipe and not changing the headers, this is a regular practice.
if you go for aftermarket (tubular) headers you will loose turbo spool, but are likely to gain topend power. Unless you are tracking the car (ie always driving in the higher RPM) or running big power, its not worth changing the headers.

Decating the uppipe will increase the spool (if it had the correct ID), however, it looks like you have a newage STi.....these dont have a cat in the uppipe could have been a waiste of time (and money) or you have a WRX??

chrisdicko

iTrader: (21)

Thanks for the replies!

Yeah, mine is a newage STI.

I just wondered really, as when you buy tubular headers, you normally seem to get the up pipe with them. So thought headers and up pipe came hand-in-hand so to speak.

KLR16V

iTrader: (2)

He may of ported out the oe headers while off the car as there is nothing wrong with oe ones once ported .


Mark

chrisdicko

iTrader: (21)

Yeah, possibly! There isnt really a way to check is there, unless I remove them?