Possible to make QUATTROPORTE S exhaust sound like GTS ?

[Mavster]

Is there any way to make the QUATTROPORTE S sound more like the GTS /Granturismo S ?

There don't appear to be valves in the exhaust, and pressing the sport button does not change the exhaust sound when the car is at idle

Thanks

 

[CatmanV2]

Unless I'm mistaken there are valved boxes for the QP, and then just add a control box

C

 

[Ebenezer]

While it appears that back boxes of non QP GT S's are "unvalved", on gutting the back box of a 4.2 there is a valve mechanism inside which operates based on the pressure of the engine exhaust. The 4.2 has twin pipes. One pipe is the exit for the more muffled exhaust route which operates when there is less exhaust gas pressure. The other is the less restricted route, and hence louder, and operates when the exhaust gas pressure is sufficient to open the valve within the back box. I presume that within the oval pipes there are two flows too and probably the same internal pressure valve.

There was a great post a while ago showing the gutted innards and the valve being welded open by Jaren Metalworks (don't be put off by his website showing metal furniture!)

Eb

Edit
Here's the post https://www.sportsmaserati.com/index.php?threads/new-owner-qp5-sport-gt.34651/post-904790

 

[Mavster]

So, just so that I'm clear. I need to remove the packing in the S back box and weld the hidden valve open ?

 

[Gazcw]

Is there any way to make the QUATTROPORTE S sound more like the GTS /Granturismo S ?

There don't appear to be valves in the exhaust, and pressing the sport button does not change the exhaust sound when the car is at idle

Thanks

Thread 'Stop Press: QPV Does Have Exhaust Valves!!' https://www.sportsmaserati.com/index.php?threads/stop-press-qpv-does-have-exhaust-valves.28898/

 

[Gazcw]

Is there any way to make the QUATTROPORTE S sound more like the GTS /Granturismo S ?

There don't appear to be valves in the exhaust, and pressing the sport button does not change the exhaust sound when the car is at idle

Thanks

Jarens metalwork on Facebook. Vids on YouTube. Here was my S with x pipe and stripped backbones.

https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.youtube.com/watch%3Fv%3DkK4caGtUarI&ved=2ahUKEwjyucXxt6__AhVoR_EDHUXZCnoQwqsBegQIARAB&usg=AOvVaw1QCtk9pBs3s0LP6WWeF98B

 

[Mavster]

Will adding an X pipe instead of a valve mod have the same increase in low down noise ?

 

[Gazcw]

Will adding an X pipe instead of a valve mod have the same increase in low down noise ?

No you need the backbox emptied. There is a bin full of wadding in them. Fixing the valves open makes it sort of a straight through box. The x pipe gives it the rasp noise.
Doing both will give you a great sound, no drone and it is still respectable when cruising and you can seek passed the rozzers quietly if you are gentle on the pedal.

For the price it is well worth it over the pain of fitting valved boxes, controllers, running vacuum pipes etc.

 

[Mavster]

Ok, car booked in to take wadding out of back boxes, then order a X pipe if required. Now is the time to tell me if I need to change tack please

 

[Ebenezer]

Please record before and after sound and take pictures of what's inside before and after

Eb

 

[Gazcw]

Ok, car booked in to take wadding out of back boxes, then order a X pipe if required. Now is the time to tell me if I need to change tack please

If you want it louder all the time, fix the valves open too.

 

[CatmanV2]

Ok, car booked in to take wadding out of back boxes, then order a X pipe if required. Now is the time to tell me if I need to change tack please

From experience empty back boxes and X-pipe is *loud*, even when you are trying not to be (that was on the 4200 though)

C

 

[Mavster]

Ideally it would be great if exhaust would sound like a GTS or Granturismo S.

 

[Mavster]

From experience empty back boxes and X-pipe is *loud*, even when you are trying not to be (that was on the 4200 though)

C

Is it best to empty back boxes 1st or put X pipe in as 1st step to the GTS sound?

 

[CatmanV2]

Is it best to empty back boxes 1st or put X pipe in as 1st step to the GTS sound?

Personally I'd go for the x-pipe first.

Then find some vaccum controlled rear boxes

C

 

[Ebenezer]

What we need to to see how a GT S back box is constructed. Also I think that the GT S comes with an unsilenced X-Pipe too.

Eb

 

[Mavster]

So is it a software thing, that gives the different sound, or the packing in the backboxes, or valves opening at different times. If it is just SW and valves, then hopefully exhaust part numbers should be the same for the S and GTS. Can anyone confirm on this?

 

[Ebenezer]

Software thing for the crackles and bangs when changing down as the GT S rev matches
Eb

 

[Gazcw]

Personally I'd go for the x-pipe first.

Then find some vaccum controlled rear boxes

C

BOOOOOORRRRRRRRIIIIIIINNNNNNGGGGGGGG!!!!!

 

[Gazcw]

If you want valves fit larini. You won't get blips with auto. The gt s software is different. X pipe will do very little other than make it more raspy.

I had an S, put on an X pipe, emptied the boxes, fixed the valves and put on larini sports cats. There was no drone and quiet enough inside due to the double glazing. There is absolutely no need for valves in my opinion.