n1scottyboy

i have just bought an 05 plate sti with a full decat exhaust system,ad to be honest it sounds great but for me too loud. could anyone tell me if i fit the cats back on and leave the back box on will i still get the same sound but at quieter levels?

djandyg

iTrader: (2)

yes, decats make things a fair bit louder.

MrLouKnee

if u put ther cats back on u will loose bhp /torque. change ther back box instead. the racebox and ninja are quieter

n1scottyboy

yes since i put the cats back on the sound has came down a few dbls . but i sure can tell the power difference since putting the cats back on the power at the top of the revs seems to tail of at the top of the revs. stills goes like stink though. would be nice to know what the bhp is now though

greatgonzo

iTrader: (1)

If you have put the cats back on you would need to have the ecu set back to standard

Mifo

iTrader: (10)

all you will need is the centre section with the resonator in it to quieten it down.
Used to have an afterburn on my old scoob , loved it but it did give you a headache after a while.

n1scottyboy

why would i need the ecu set back to standard ,i got told i could leave it with my remap but i would not get the full benifit of the remap cause i changed the catsback on although i have a uprated fuel pump and k@n induction kit and the vortex back box and pipe it would still have more power and prob better fuel cosumption.

midnight

iTrader: (10)

Just adding the centre resonator would have reduced the noise level & some of the flow from the exhaust,but if you have put the primary cat back on as well , then you will not get the full benefit of your remap.If your vortex was to loud could you not have bought the silencer bung ,yes it does sap the power a little ,but is great for long steady motorway journeys with no cabin drone at all,and can be fitted/removed in 30 seconds.
Failing that if you know who mapped the car initially then surely a 'tweak' to the map may be all that is needed to ensure your getting the best out of the slight modifications you have made.

B0DSKI

iTrader: (17)

As Mifo says a resonated centre section will quieten it down a fair bit. I've got a Prodrive one off of a MY2003 STi PPP knocking about if you're interested