Tuning, Exhaust question L99

[tom692010]

Originally Posted by hoffmk2003

I hope to god GM engineers don't sign in here and read some of these posts. That "chamber" was probably a team of 5-10 engineers entire project on the L99 camaro for 3 years designing the acoustics and performance of that.

They days of 40 years ago where things were just slapped together for no apparent reason are long gone, everything has a purpose now and is optomized. Realize this before you start changing your cars parts, you might not always get what you wanted.

Ken

I deal with engineers everyday.Just because they do something doesn't mean it's always right.

[Switchback700]

Originally Posted by tom692010

I deal with engineers everyday.Just because they do something doesn't mean it's always right.

So do I, for 25 years.... that's why I didn't feel too bad making that post. For hiding the sound of AFM, I'm not questioning how much time and engineering they put into that exhaust. Too bad GM couldn't save all those man hours and delivered the A6 without AFM, would have saved us consumers a lot of headaches and money too. But the engineer's hands are tied with Corporate decisions.

[SGOS252382]

You should get Magnaflow 2.5 Catback exhaust to go with your headers. It will be perfect for what you're wanting. It will not be loud, but still sound really good and people will know you're car isn't stock. You'll also have a nice quiet cruise without drone. The Magnaflow 2.5 comes with a resonated X pipe along along with Magnaflow's regular mufflers to really keep the noise level in check.

[hoffmk2003]

Originally Posted by Switchback700

So do I, for 25 years.... that's why I didn't feel too bad making that post. For hiding the sound of AFM, I'm not questioning how much time and engineering they put into that exhaust. Too bad GM couldn't save all those man hours and delivered the A6 without AFM, would have saved us consumers a lot of headaches and money too. But the engineer's hands are tied with Corporate decisions.

the thing that most people don't realize is just because you want your car loud and with less fuel economy doesn't mean the 130k+ people who also bought camaros do

Manufacturers have to meet strick EPA economy requirements not just for a single vehicle but as an entire company. Which means they have to do things like sacrifice some performance on the A6 to help meet the corporate quota for fuel economy.

Also, they do things called market research which entails figuring out what the average A6 byer will want vs an M6 buyer. They probably found out that the A6 buyer is older and doesn't want the car to be overly loud and values comfort and fuel efficiency more than a M6 driver.

So before you slam a very good design and a great effort by GM think about why it is the way it is. If you don't like it change it, but don't call it crude. It's got a lot more acoustical analysis, computational fluid dynamics and other work done to make it silence that 4 banger mode than you think.

Oh and I deal with engineers all day to, I am an engineer and have worked as an aerospace strutural analyst, a senior quality engineer and many other positions. I do make mistakes I'm human, but if there was that much effort into that "crude" little design I doubt it was by mistake. That took some serious work to make it perform and meet the noise requirements for the exhaust.

Rant off.

Ken

[tom692010]

I stand by my statement.I work in the pharmecutical industry and I've handed P&ID's with pipes running into electrical boxes. Or equipment that isn't worth a darn and they spent just as much time working on that project too.The word Engineer shouldn't be confused with a group of people who are all knowing. And granted they have many restrictions such as cost that they have to deal with so everything isn't always the way they would do it it if the budget was unlimited.

[slickmetal]

Originally Posted by hoffmk2003

the thing that most people don't realize is just because you want your car loud and with less fuel economy doesn't mean the 130k+ people who also bought camaros do

Manufacturers have to meet strick EPA economy requirements not just for a single vehicle but as an entire company. Which means they have to do things like sacrifice some performance on the A6 to help meet the corporate quota for fuel economy.

Also, they do things called market research which entails figuring out what the average A6 byer will want vs an M6 buyer. They probably found out that the A6 buyer is older and doesn't want the car to be overly loud and values comfort and fuel efficiency more than a M6 driver.

So before you slam a very good design and a great effort by GM think about why it is the way it is. If you don't like it change it, but don't call it crude. It's got a lot more acoustical analysis, computational fluid dynamics and other work done to make it silence that 4 banger mode than you think.

Oh and I deal with engineers all day to, I am an engineer and have worked as an aerospace strutural analyst, a senior quality engineer and many other positions. I do make mistakes I'm human, but if there was that much effort into that "crude" little design I doubt it was by mistake. That took some serious work to make it perform and meet the noise requirements for the exhaust.

Rant off.

Ken

Yeah but it sucks when you need an A6, because excessive shifting hurts your already hurt knees, like myself...I am still young but A6 is the one for me for some comfort...but to find out, you pay roughly 1000$ more for the A6, get less Fly/RW horsepower and far less superior engine internals compared to the LS3...then you also have to deal with little annoyances when upgrading to headers/exhaust because of the AFM/harmonic frequencies/etc. The MPG difference is not too too much over the M6. I almost didnt buy it when I found out about the HP loss...

[jbsrace1]

My favorite L99 exhaust setup. Has a nice rumble but is quit wile cruising down the highway with No drone at all running 55 with afm working & gets nice and loud when you jump on it.

[Switchback700]

Originally Posted by hoffmk2003

the thing that most people don't realize is just because you want your car loud and with less fuel economy doesn't mean the 130k+ people who also bought camaros do

Manufacturers have to meet strick EPA economy requirements not just for a single vehicle but as an entire company. Which means they have to do things like sacrifice some performance on the A6 to help meet the corporate quota for fuel economy.

Also, they do things called market research which entails figuring out what the average A6 byer will want vs an M6 buyer. They probably found out that the A6 buyer is older and doesn't want the car to be overly loud and values comfort and fuel efficiency more than a M6 driver.

So before you slam a very good design and a great effort by GM think about why it is the way it is. If you don't like it change it, but don't call it crude. It's got a lot more acoustical analysis, computational fluid dynamics and other work done to make it silence that 4 banger mode than you think.

Oh and I deal with engineers all day to, I am an engineer and have worked as an aerospace strutural analyst, a senior quality engineer and many other positions. I do make mistakes I'm human, but if there was that much effort into that "crude" little design I doubt it was by mistake. That took some serious work to make it perform and meet the noise requirements for the exhaust.

Rant off.

Ken

Who said I want my car loud with less miles per gallon? I would like my car to sound like a Camaro V8 not a Cadillac, and as far as mileage there are people matching or getting better mileage without AFM and getting a tune.

I understand the EPA requirements and that is why I said the engineer's hands were tied.

The quietness of the A6 in not because of market analysis it is because of AFM. I find it very hard to believe that the "older" people buying the A6 would have requested a more comfortable, quiet, fuel efficient CAMARO.... It's a Camaro not a Buick.

I believe I have said the exhaust design for AFM is good, at hiding the 4 cyl mode. I just firmly believe the AFM should not be on a musclecar, whether it had to be is another debate. The crude comment included a ? because I didn't see an actual X pipe in the resonator.

I have seen many "crude" and stupid designs in the Automotive business because of time constraints and budgets. Whether this is one of them will continue to be debated, but I believe there are aftermarket products that are already proving this design could be improved.

[Switchback700]

Originally Posted by jbsrace1

My favorite L99 exhaust setup. Has a nice rumble but is quit wile cruising down the highway with No drone at all running 55 with afm working & gets nice and loud when you jump on it.

If this is true, and AFM drone is controlled, and you get better V8 sound.......... it makes the huge resonator design look like a little overkill then...... hmmmmm and the debate continues

[Switchback700]

I've also heard good things about the Solo axle back with a Helmholz J pipe...... that would probably be my first mod if I wanted more sound and to to keep AFM (maintain warranty), but I am past that point and have my appointment with Livernois next week.... can't wait.....