2021 GT sound tube, and quiet exhaust?

[Roadway 5.0]

There you go...worth looking into because I can tell you for certain a N. American GT in Geneva would be impounded immediately for sound violation haha.

I drove all through Switzerland a few times in my N. American GT with aftermarket Borla Touring exhaust. No issues, but then again I never went to Geneva .

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[Vlad Soare]

There you go...worth looking into because I can tell you for certain a N. American GT in Geneva would be impounded immediately for sound violation haha.

I can't comment on Geneva, as I don't know the Swiss law regarding noise levels. But frankly, a country where I'd be afraid to even sneeze without proper authorization lest I be sent to jail for a hundred years doesn't look like a relevant benchmark to me. All I can tell you is that many US Mustangs are legally registered in the EU, and the only thing that is required to be adjusted (in some of the EU countries, not all) is the lighting system. Mufflers are not an issue.

 

[Vlad Soare]

Homogolization varies from country to country and goes way beyond lighting in most, if not all, EU countries.

Sure it does. And yet most Europeans who import US vehicles and have them registered here in their name have no trouble with anything but the lights (and even the lights are OK in some countries). Which goes to show that US mufflers aren't actually as illegal as they may seem.

 

[Vlad Soare]

I've noticed something interesting. Even in Track mode the valves aren't always 100% open.
This is the table it uses for Track mode:

What gives?

 

[Mach VII]

I've noticed something interesting. Even in Track mode the valves aren't always 100% open.
This is the table it uses for Track mode:

What gives?

That's weird. I thought maybe mine was different because I was reading the FRRP tune but I looked at my stock file and it was the same - open fully in all circumstances. Mine might be different because my car did not come stock with AE or perhaps our files are different because yours is an export version and faces different regulations. how does it compare to your 'Sport' table?

 

[Vlad Soare]

This is the Sport table.

It looks a bit different from yours here and there, though overall it does seem to be broadly similar.

Indeed, being a Euro model might have something to do with it. I didn't think of that.

 

[Vlad Soare]

Actually, at a closer look it seems that while the overall shape of the colour distribution may be broadly similar, the actual values are lower everywhere.
This may indeed be a Euro thing.

 

[Vlad Soare]

The Sport table makes sense. They kept the same strategy as in the US, but just turned it down one notch over the entire range to keep our oversensitive beaurocrats happy.
So, I guess I can just copy the US table and I'll be fine.

However, the Track table doesn't seem to fit this logic. It still has 100% in the most frequent situations, and it closes the valves quite abruptly only when you step hard on the gas at low to medium revs - something that's both infrequent and unlikely to cause any extra noise. Besides, with an automatic this will never happen, since it will downshift.
So, this doesn't seem to do anything to help with noise regulations.
Can there be another, more technical, reason for it? Like, say, increasing back pressure to help with low rpm torque? The fact that the valves only close when the engine is under-revved seems to indicate that. But I'm just thinking out aloud.

 

[Vlad Soare]

Another strange thing: the tables only go to 5500 rpm. What happens after that point?

 

[Vlad Soare]

Something doesn't seem to work as expected.
I've uploaded the following tables:

For Normal mode:

For Sport mode:

Here's how the valve looks in Normal mode at warm idle. This doesn't look like 90% to me. It looks more like 30 to 40%.

Here's how the valve looks in Sport mode at warm idle. This is clearly less than 100%.

In Track mode it looks perfect. Fully open, as expected.

So the PCM doesn't seem to take the modified tables into consideration.

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