Maserati Granturismo 2013 X Pipe Exhaust

[Sam McGoo]

for fear of being kicked from forum, imho the 4.7 produces the right amount of beautiful, soul-full noise without X, H or whatever after pipes.........leave perfection alone!
i'll get my coat.

Your right. Standard 4.7 S (well, the ones that have valves open all the time in sport) are sublime, and nearly perfect.
I nearly didn't, but personally run a larini x-pipe for a bit more volume and a few more audible crackles and burbles, but you do sacrifice a little tone 'class' and gain a little rasp. But it's not too much and I won't take the x-pipe off now.

OP-My advice, if you're unsure, would be hold off getting one until you get a little bored, or feel the need to spice things up a bit. Then when you do it, it'll feel like a different car, and you'll fall in love all over again.

 

[Sam McGoo]

Well not quite relevant here, but I have the 4.2 and welded spindles onto the valves inside the box so that I could play with them and see how they work. Surprisingly they don’t open when revving in neutral and they only open up much above the 3500 when accelerating hard and quickly shut again when power is lifted off a bit. I guess the 4.7s operating on vacuum must open up a lot more, with the possibility of leaving them open in Sport mode.

Not sure what my final plan will be, tempted by 4.7 boxes, but at £1k secondhand, think I will play with my boxes more as it is free! For those with 4.2s, jamming valves open does not make much difference to noise.

If I was on a budget, I'd cut open the back boxes and remove the wadding.

I've done it on previous cars when aftermarket options were rediculous money, and it sounded great.
You get the distinctive tone of the oem design, but more volume.

 

[Zep]

Well not quite relevant here, but I have the 4.2 and welded spindles onto the valves inside the box so that I could play with them and see how they work. Surprisingly they don’t open when revving in neutral and they only open up much above the 3500 when accelerating hard and quickly shut again when power is lifted off a bit. I guess the 4.7s operating on vacuum must open up a lot more, with the possibility of leaving them open in Sport mode.

Not sure what my final plan will be, tempted by 4.7 boxes, but at £1k secondhand, think I will play with my boxes more as it is free! For those with 4.2s, jamming valves open does not make much difference to noise.

The valves open through the build up of back pressure through the open side of the back box. As the volume flow of exhaust is much greater under load (so they open when driving, not reving) and that flow stops pretty abruptly on a closed throttle, it sounds like they are working as expected.

Others have welded the valves open and removed the wadding to good effect.

 

[Ebenezer]

Well not quite relevant here, but I have the 4.2 and welded spindles onto the valves inside the box so that I could play with them and see how they work. Surprisingly they don’t open when revving in neutral and they only open up much above the 3500 when accelerating hard and quickly shut again when power is lifted off a bit. I guess the 4.7s operating on vacuum must open up a lot more, with the possibility of leaving them open in Sport mode.

Not sure what my final plan will be, tempted by 4.7 boxes, but at £1k secondhand, think I will play with my boxes more as it is free! For those with 4.2s, jamming valves open does not make much difference to noise.

I too have a 4.2 and have fantasised for years about doing something to the back boxes so very interested in your experimentation! What's the difference internally with the valves open? Is it that valves closed you go though wadding and out out if one of the two pipes and open, there is less/no wadding and the exhaust passes out of rhr other pipe?
Internally what's different between the 4.2 and the 4.7 when the valves are open?
Eb
Eb

 

[modelT]

I have not really noticed any difference internally. Whether valves open or closed, the pipes go through wadding. I did a video of it and it was a bit inconclusive, however it has given me the confidence to be more harsh in my next dive into the boxes. (Sorry to put another video link up)

 

[Zep]

I too have a 4.2 and have fantasised for years about doing something to the back boxes so very interested in your experimentation! What's the difference internally with the valves open? Is it that valves closed you go though wadding and out out if one of the two pipes and open, there is less/no wadding and the exhaust passes out of rhr other pipe?
Internally what's different between the 4.2 and the 4.7 when the valves are open?
Eb
Eb

@Gazcw has been here before, so details for you Eb.

Post in thread 'Stop Press: QPV Does Have Exhaust Valves!!'
https://www.sportsmaserati.com/inde...v-does-have-exhaust-valves.28898/post-1015019

 

[Sam McGoo]

@Gazcw has been here before, so details for you Eb.

Post in thread 'Stop Press: QPV Does Have Exhaust Valves!!'
https://www.sportsmaserati.com/inde...v-does-have-exhaust-valves.28898/post-1015019

I was looking for that fur ages earlier lol. But was searching, backbox... Muffler, wadding, baffles

 

[Gazcw]

I too have a 4.2 and have fantasised for years about doing something to the back boxes so very interested in your experimentation! What's the difference internally with the valves open? Is it that valves closed you go though wadding and out out if one of the two pipes and open, there is less/no wadding and the exhaust passes out of rhr other pipe?
Internally what's different between the 4.2 and the 4.7 when the valves are open?
Eb
Eb

Yes. Valve opens internally and it is direct out of the second larger bore pipe. Smaller bore goes through wadding. Open them up pull the wadding out that will fill a bin and you will have slightly louder normally. Fix open the valve and you have loud all the time. X pipe will give you the rasp to go with loud. Sports cats with it will make pedestrians ears bleed. No drone in either set up. You can creep past the fuzz still with a light right foot.

Cheapest exhaust mod you can do and it works.

 

[Gazcw]

I was looking for that fur ages earlier lol. But was searching, backbox... Muffler, wadding, baffles

I would never start a thread called backbox, muffler, big bore or wadding on this forum! Crud gets way too over excited.

 

[Gazcw]

for fear of being kicked from forum, imho the 4.7 produces the right amount of beautiful, soul-full noise without X, H or whatever after pipes.........leave perfection alone!
i'll get my coat.

Pick a window too....

 

[modelT]

Yes. Valve opens internally and it is direct out of the second larger bore pipe. Smaller bore goes through wadding. Open them up pull the wadding out that will fill a bin and you will have slightly louder normally. Fix open the valve and you have loud all the time. X pipe will give you the rasp to go with loud. Sports cats with it will make pedestrians ears bleed. No drone in either set up. You can creep past the fuzz still with a light right foot.

Cheapest exhaust mod you can do and it works.

Quick question as I did not cut into the half of the box with the wadding, are both pipes that go through there perforated?

I have left my valves fully open for now, but one has started rattling against the bolt at times. I can easy fix that with dab of weld.

 

[Gazcw]

Quick question as I did not cut into the half of the box with the wadding, are both pipes that go through there perforated?

I have left my valves fully open for now, but one has started rattling against the bolt at times. I can easy fix that with dab of weld.

No the larger bore is solid and simply is basically a J from the exit through to the valve. Checkout Jaren Metalworks youtube page. I was the guinea pig for him. There maybe a pic or video of the box open.

 

[Gazcw]

Quick question as I did not cut into the half of the box with the wadding, are both pipes that go through there perforated?

I have left my valves fully open for now, but one has started rattling against the bolt at times. I can easy fix that with dab of weld.

I have just posted an xpipe for sale too.

 

[Felonious Crud]

I would never start a thread called backbox, muffler, big bore or wadding on this forum! Crud gets way too over excited.

Sadly, you were right.