Variable Exhaust Valve Timing and aftermarket exhaust systems/muffler delete

[MetCom45]

Hey everyone,

I did a search of the forum and I didn't find anything specific to the question I have. If I do a muffler delete with my 2005 LS V8 will that effect power, fuel economy, longevity or have any other negative effect because of the variable exhaust valve timing in the 2nd gen 3.9L? I am unsure if changing the pressure in the exhaust system will wreak havoc with the variable exhaust valve timing.

I installed the K&N CAI from the Ford Thunderbird (Here) and I absolutely love the new sound coming from my engine bay. Now I just want more..

I really don't feel like spending $800+ on something like This, but I also don't want to reduce performance in anyway shape or form. Or do damage for that matter.

I do realize that a muffler delete will be extremely loud and raspy at certain RPM's and that's not really the solution I want. Is it possible to modify the existing mufflers to let a bit more sound through? Such as removing the baffles from the mufflers? (I have no experience with modifying exhaust systems or mufflers, but I know of people removing baffles on motorcycles)

Thanks for any input, I appreciate it!

 

[oddball]

There are lots of threads on exhaust sound. Read up. Some folks do resonators only and like it. The resonators mean it won't be an open pipe.

Changing the exhaust system doesn't affect the VVT much, if any. Don't sweat it.

 

[MetCom45]

Ok cool, thanks man!

And yeah I found a ton of exhaust related threads, just no one discussed the VVT in depth.

 

[joegr]

Ok cool, thanks man!

And yeah I found a ton of exhaust related threads, just no one discussed the VVT in depth.

VV timing is no more or less affected by exhaust back pressure than normal fixed valve timing is.

 

[Robot]

The VVT is done only on the intake valves.

 

[MetCom45]

VV timing is no more or less affected by exhaust back pressure than normal fixed valve timing is.

Ok, that's essentially what I was asking. That clarifies it perfectly.

 

[MetCom45]

The VVT is done only on the intake valves.

According to what I've read from a few different sources (found through a Google search) one of the key factors in the nearly thirty horsepower increase from the 00'-02' model year and the updated 03'-06' model was because of a newly introduced Variable Exhaust Valve Timing (Alongside the new intake VVT). So apparently VVT can be done for both the intake and exhaust valves.

 

[Robot]

According to what I've read from a few different sources (found through a Google search) one of the key factors in the nearly thirty horsepower increase from the 00'-02' model year and the updated 03'-06' model was because of a newly introduced Variable Exhaust Valve Timing (Alongside the new intake VVT). So apparently VVT can be done for both the intake and exhaust valves.

That makes perfect since. I will stand corrected. I was wondering about that info and I really didn't understand why it would only be on the intake. Thanks! That might explain why I get a different exhaust note too.

 

[MetCom45]

That makes perfect since. I will stand corrected. I was wondering about that info and I really didn't understand why it would only be on the intake. Thanks! That might explain why I get a different exhaust note too.

Haha no prob. A different exhaust note relative to what? A different year LS?

 

[Robot]

Haha no prob. A different exhaust note relative to what? A different year LS?

No, just seems like it will sound really throaty and other times it will sound quite raspy. I am actually surprised I can hear it at all with light throttle.

 

[Gus_Mahn]

I also have a CTS-V and those guys who want a little more sound holesaw a hole in the top of the muffler and pull the stuffing out through the hole. The hole is the size of a bicycle handlebar plug which is siliconed into the hole on the top of the muffler. I've heard one and it sounded nice, just a little more raspy and louder than stock.

 

[MetCom45]

No, just seems like it will sound really throaty and other times it will sound quite raspy. I am actually surprised I can hear it at all with light throttle.

Ohh ok yeah I know what you mean. And when I am in a high gear at low RPM (SST transmission) I notice that if I step on it without changing gear the engine noise changes pitch. It must be one off the VVT's kicking in that I can hear.

I also have a CTS-V and those guys who want a little more sound holesaw a hole in the top of the muffler and pull the stuffing out through the hole. The hole is the size of a bicycle handlebar plug which is siliconed into the hole on the top of the muffler. I've heard one and it sounded nice, just a little more raspy and louder than stock.

That's brilliant!! Thanks for the suggestion. I'll post my results if I do that.