MarcelGt

Hello! I own an impreza and I'm writing from Barcelona ... I just bought a downpipe in uk and people tell me that this model does not work, I'd have to be a separate mouth... its correct?

this is the one who bought :





and this where I say it would be better:




My car is standard and wanted to earn some benefits hp without making much noise because its my daily car..

you can tell me advantages and disadvantages of each system?

Best regards from Barcelona!!

joz8968

iTrader: (13)

The one you've bought is an OEM style one where the blanked-off side seriously restricts the w/g's dumped air.

The second one pictured is much better... but best to get a fully open bellmouth design, with NO divider whatsoever...

MarcelGt

Ok.. thanks for the reply !. but it can damage the engine? then the original downpipe is like this or is it more open?

joz8968

iTrader: (13)

lol, no it won't damage the engine - it's just not as efficient in getting the w/g's dumped charge out of the system, that's all. The w/g's dumped air is effectively being forced around two sharp 90 degree turns, before exiting.

Whether you could actually quantify/feel it on the road is a moot point, I suspect.

BTW, it's advisable getting the car mapped, or, at the very least, the AFRs/boost behavior checked, after you fit a decat.

midnight

iTrader: (10)

As joz says the one you've bought is like your o/e downpipe without the cat ,you are much better off with one like below as they allow more of your exhaust gases through the downpipe:

MarcelGt

Ok! I have the car for two months only and its all stock..
the car has been the all life of a grandfather to go with the family to the ski mountains..

when I get it mounted I'll tell you the feelings!!

I've already been to a trackday last month but before a lot of power I prefer to put better suspension and brakes

I purchased a gold brembo kit and I'm looking for coilovers

the car is changed all the fluids and belts and has been installed gauge pod to control pressure turbo and oil temperature

here in Spain we are far behind in matters of subarus..

Greetings and very friendly!

MarcelGt

and now the last question .. now if I do not want to do a remap the best choice would be the mouth closed that I have purchased?

(In the future when I buy more things I makes a remap)

joz8968

iTrader: (13)

The more restrictive nature of the one you've bought is prob more "safe" than a bellmouth, if not getting mapped. But why bother? I'd just sell yours... replace it with a bellmouth... then get remapped (with any other useful mods, etc), all at the same time.

Bit pointless in fitting a (less efficient) designed one, and not remapping it -- you may as well just keep your OEM catted one (knowing it's OEM-safe!), until you have the funds/time to do the above suggestion, in one go...

Dutch Scooby lover

iTrader: (3)

In theory the open/bellmouth downpipe makes a difference, but I think anything at under 330chp you will not notice it too much.

A mate of mine and myself had the same setup (td05-Evo3 16G, FMIC,remap)
and while I had a 2.5 non-bellmouth downpipe, and he had a 3" with a bellmouth there was nothing in it.

So maybe over 330 you see a difference, for what you want this is more then enough, and already a substantial upgrade over the catted stock downpipe.