sport mode - exhaust not working?

[Contigo]

On this thread FD have a fob application to control valves and also a schematic for other solutions.

http://www.maseratilife.com/forums/granturismo/15548-exhaust-valve-modification-2.html

 

[Felonious Crud]

Thanks Phil!

 

[Felonious Crud]

Dropped in to see the Oracle of Halsted this morning. He pointed out that having exhaust valves closed all the time is a bad thing when you're driving enthusiastically because the extra flow is necessary to stop the cats getting bolloxed. They should open by default at 4,500rpm, I think, but mine don't do that. Booked in for a fix, and in the meantime I'll remove and seal the vacuum pipes and seal the male pipe connection on the valves as well.

We discussed fitting an over-ride switch. Now, in an ideal world it would be possible to separately set the handling from normal to sport as well as exhaust and gear-changes. To my mind the gear-changes should always be quick, handling can sometimes be normal and on a run having a quieter exhaust can be nice. But as far as I know you can't separate ride/steering and gear-changes.

As an alternative having the possibility of quiet exhaust in sport mode or loud exhaust in normal mode could be good, but only if the exhaust would still open at 4,500 rpm regardless of what you've selected. Which is what I'll aim for. I'll report back.

 

[Contigo]

Omg Adam! You can open them permanently using the Golf Tee mod, did you see it?

I can't decide now whether yours were stuck open or shut!

 

[Felonious Crud]

Omg Adam! You can open them permanently using the Golf Tee mod, did you see it?

I can't decide now whether yours were stuck open or shut!

Northern tw4t.

I actually had mine permanently open but shut them up for the MOT and decided it was time to get them fixed properly. Even though I love the noise the occasional 4am start through my small village isn't very courteous. Incidentally, no golf tee required. I just taped 'em up and used cable ties to bend the pipes double, to be sure. If you leave them unblocked you'll suck God knows what **** up your pipes* and throw a CEL.

*Dem, settle down.

All - does anyone know if there's a way of shutting Phil up permanently..?

 

[StuartW]

Now, in an ideal world it would be possible to separately set the handling from normal to sport as well as exhaust and gear-changes. To my mind the gear-changes should always be quick, handling can sometimes be normal and on a run having a quieter exhaust can be nice. But as far as I know you can't separate ride/steering and gear-changes.

As an alternative having the possibility of quiet exhaust in sport mode or loud exhaust in normal mode could be good, but only if the exhaust would still open at 4,500 rpm regardless of what you've selected. Which is what I'll aim for. I'll report back.

That would certainly make much sense, on the roads I drive on around here I would often prefer the noise without the stiff suspension - it is by far my biggest & possibly only bug bear with the car

 

[Contigo]

Northern tw4t.

I actually had mine permanently open but shut them up for the MOT and decided it was time to get them fixed properly. Even though I love the noise the occasional 4am start through my small village isn't very courteous. Incidentally, no golf tee required. I just taped 'em up and used cable ties to bend the pipes double, to be sure. If you leave them unblocked you'll suck God knows what **** up your pipes* and throw a CEL.

*Dem, settle down.

All - does anyone know if there's a way of shutting Phil up permanently..?

**** off you Alan Partridge soundalike!

I honestly am trying to help but I can't decide whether it's me being thick as **** or you!

 

[Contigo]

My understanding is that the valves open in Auto Sport mode at 3.5k and above. In Manual Sport they are open all the time. There is absolutely no issue with the valves being shut all the time!

 

[Felonious Crud]

I honestly am trying to help but I can't decide whether it's me being thick as **** or you!

Must be you. It's clear enough to me.

 

[MAF260]

**** off you Alan Partridge soundalike!

I honestly am trying to help but I can't decide whether it's me being thick as **** or you!

It's definitely you!

 

[Felonious Crud]

There is absolutely no issue with the valves being shut all the time!

According to Rob they need to open when you're giving it the beans otherwise the cats can overheat. According to me they need to open because it sounds better. The practical upshot's the same - I want the buggers to open!

 

[BennyD]

The GS exhaust valves are designed to open automatically when the gas flow exceeds a certain amount, and I'm pretty sure it's to make sure you don't cook the cats.

 

[Felonious Crud]

The GS exhaust valves are designed to open automatically when the gas flow exceeds a certain amount, and I'm pretty sure it's to make sure you don't cook the cats.

Thanks Ben. That's tallies with what Rob said - closed valves + big revs = cooked cats.

 

[CatmanV2]

Thanks Ben. That's tallies with what Rob said - closed valves + big revs = cooked cats.

Indeed it does

C

 

[Contigo]

Thanks Ben. That's tallies with what Rob said - closed valves + big revs = cooked cats.

Ok in that case why does it not open the valves when in normal mode at 5k rpm? The valves are so far behind the cats that I cannot see it making the slight bit of difference to cat temps.

 

[Felonious Crud]

Ok in that case why does it not open the valves when in normal mode at 5k rpm? The valves are so far behind the cats that I cannot see it making the slight bit of difference to cat temps.

I'm sure someone with a mind more more finely tuned to the delicacies and details of automotive exhaust systems will be along soon with a more informed answer, but my understanding is that open valves allow a greater throughput and expulsion of exhaust gases, thus allowing for faster airflow over the cats and hence helping keep them just that bit less hot.

But that's just a guess. Simple fact is they don't open and I'd like them to. I'll have Rob fix the underlying problem and at the same time fit a remote override, as per your post above, to give me more flexibility than Maserati, in all its wisdom, decided to bestow upon us all.

 

[Contigo]

That would certainly make much sense, on the roads I drive on around here I would often prefer the noise without the stiff suspension - it is by far my biggest & possibly only bug bear with the car

I think that's why a non skyhook model is the oft preferred version in the GTS.