Dyno test and active exhaust

[ICU812]

Hello, I am thinking someone must have done this.
Testing on a chassis dyno with the exhaust in quite mode, then normal, then track.
To see how much ,if any power swing there is between one mode and another.
Has anyone?

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[Bikeman315]

Hello, I am thinking someone must have done this.
Testing on a chassis dyno with the exhaust in quite mode, then normal, then track.
To see how much ,if any power swing there is between one mode and another.
Has anyone?

My understanding is that once you dip deep into the throttle the valves go to full open regardless of initial setting.

 

[ICU812]

My understanding is that once you dip deep into the throttle the valves go to full open regardless of initial setting.

That would make sense.

 

[Schwerin]

My understanding is that once you dip deep into the throttle the valves go to full open regardless of initial setting.

I've heard that too, but I've punched it on the HW when in Quiet and the car NEVER got as loud as Track Mode or even Sport.

 

[boB]

As I recall a Corvette system added a whopping 5 HP.

 

[Bikeman315]

I've heard that too, but I've punched it on the HW when in Quiet and the car NEVER got as loud as Track Mode or even Sport.

I'm thinking the system knows the difference between a momentary "punch" and WOT you would do on a Dyno. I do not know of anyone on this forum who tried it.

 

[brucelinc]

I don't know about power increase if any but there is a significant difference in sound between WOT in quiet or normal vs. WOT in track.

 

[2morrow]

So a friend of mine with an active exhaust on his roush did some pulls and there was this super weird sounding exhaust transition when doing the pulls.

I would just always keep it open unless having to leave the neighborhood quietly in the early AM.

That's just me though.

 

[MRGTX]

A while back, folks confirmed that if you do WOT pull in quiet mode, the valves do blow open at some point...unclear if this is a programming thing or if they are just forced open by the gas pressure.

I guess this means that the exhaust modes only make a difference if you are putting around town. Once you give it the beans, all the modes are the same.

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