Paramount performance makes both an exhaust and racing cats, I have their exhaust on my XKR, but not the cats.

 

CVPREZ.........did you have dealer install upgrade?if so, mind saying how much?Does it allow the full sound to release at lower RPM? ( as appossed to the factory controlled version)

 

It was installed by aftermarket shop - roughly $2000 and yes it eliminates the opening and closing of the active exhaust

 

Thanks

Im checking with my dealer to see if it will give me warranty issues to change out....if they dont do the upgrade themselves.....chances are they will try to talk me out of it(unless they will do it for me). I would like to have exhaust opened up and not dampered!!!!!!

 

My local dealer wont install Paramount exhaustsystem, but said that if cat-back only installed.....Im good with warrenty issues. What Ive heard on YTube....http://www.youtube.com/watch?v=Uk3kQGzYxl8 just changing the muffler system is pretty sweet.

 

Update.....I had a performance shop disable the vacuum controlerand leave exhaust dampening valves open....took about 15min....He called Dealer to see if any issues with doing this and they said only possible thing would be check engine light MIGHT activate and said they would turn it off for free if it came on. So far( two days of driving) no problems....just constant meaty growling from the rear.....sounds awesome when using manel shifting on wheel

 

Your stock manifolds are not restrictive.... Unless your swapping the supercharger or stroking the motor out, you really have no need for headers.. At most you could pick up 5-10hp from a set of custom headers, but you would be surprised how good the stock manifolds flow.. By increasing the size of your primary tubes with aftermarket headers you decrease air velocity and in turn decrease your torque, but you gain some/minimal top end power.. The only power to be had is with "full length headers" that match the lengths of all four primary tubes on both sides, BUT stock manifold with short tubes will actually yield more power at lower RPMs.. Its a very specific math equation that Im sure you probably dont want me to go in depth with.. but basically until you find a way to add 50-100hp to your motor (i.e. Intake, Pulley, Twin Screw Blower, ECU tune, Ported heads, etc.) you could potentially do more bad than good by swapping your manifolds to a custom header setup.. My advice would be leave the manifolds alone and play with the cat back setups to get the sound how you want it... but even with exhaust, no back pressure from a straight through exhaust will kill your torque, so dont go nuts with it. Hope this clears up any confusion.. Eric

 

Sad advice there Eric,naysaying sucks.

 

As I recall the vacuum valves on the back box are CLOSED with vacuum and are normally OPEN . So if you want them open all of the time you can disconnect the vacuum line and plug it and they will stay open and no MIS light.

 

Resurrecting a thread from 2008 must be a record! Simple and free solution to getting more noise from your XKR is to pull fuse 19.

 

I smell a troll

 

 

Holy thread resurrection Batman!

This one's a full 12yrs, are you going for a record!?

On topic my car has the paramount performance exhaust which is from the H pipe backwards with no rear box.
Despite those and the smaller upper pulley and k&n's it's down 17 on stock with a standard tune...which is fine with me as never get to use the full power anyway