05 WRX;

Currently centre decat system through to ninja BB which is louder (obviously) than std. pea shooters but nice, not boomy just a nice growl.

Now I'm about to go full decat and it's going to be louder, which I accept, however I'm a bit concerned it might be too loud..!

So basically, just how much louder is a full decat..?

Cheers,
Jason

PS before anyone points out warranty inplications, I've got a very understanding dealer..!

 

Much. Be prepared. Warn the neighbours. Be very embarassed while warming the car up on a frozen January morning to de-ice the windows at 5am.

 

think thats a bit much to say that, my mates got one and it aint alot louder!!!!!!!!!!!!!!!!!! just a bit... Sounds really nice!

 

didn't say it doesn't sound nice...

 

Hmmmm..!

I suppose it's something I'll get used to, just don't want it to be too embarrassing..!

When I had the centre through BB done it sounded LOUD but that was because I was used to the 'milk float' quietness of the oem system.

It did quieten (sp?) after a week or too though and not just me getting used to it, I think it must have carbonised up or something. Have heard about this happening before.

I suppose if it is too much I'll have to consider a slightly quieter BB..! Ultimately I'd like a sports cat down pipe at some point.

Thanks
Jason

 

If you fit a quite back box don't worry is the most critical exhaust part regarding noise although it doesn' affect remarkably performance as other sections!

 

Agreed - having got tired of the noise from a Milltek full system I tried putting the original STi back box on. Like night and day - can't hear the exhaust at all, in spite of all that 3-inch pipework from the turbo back. No performance handicap, it actually feels a lot stronger probably because the engine seems to be completely unstressed. Got rid of the drone at motorway speeds, and got rid of all the other exhaust noise too !

Apparently it now sounds like a vacuum cleaner on steroids... not everyone's cup of tea though.

 

IF you replace the centre section with a well resonated one, and fit one of the quieter sports cat downpipes, the noise at tickover/very low throttles needn't be much louder than the noise you have now - although it will roar more at wider throttles.

As Ricardo says, if you fit a quiet backbox onto the back of a decat system, you can get a quiet car with a full decat/sports cat system fitted with the OEM or other very quiet backbox.

 

Cheers guys

 

It won't really be that louder on tick over if at all.

It will however be louder on full boost when the speed is buiding up and you should also be able to hear the turbo spool at all speeds.

Mick

 

Got it done today at scoobyclinic (what a place..!) and I quite supprised that it isn't that much, if any difference..! Still may change to a quieter BB at some point.

Just need the exhaust wrap to stop smoking/smelling... still smoking/smelling after 1 hour journey home on M'way..!

Not noticed any performance gains yet, however I won't give it too much until it's remapped on Sat.