The Pittsburgh Thread

[demonspeed]

Originally Posted by Juniorv130

Hey everyone, I finally was able to join the 5th gen camaro family yesterday! 2010 Red Jewel 2SS/RS 6 speed. So pumped. Now if this crap Pittsburgh weather would break.

Anyone Have any recommended mods? Axle back exhaust is coming first...

Welcome to the thread!

As for mods... I can think of plenty of ideas... the question is how much are you willing to spend?

[Seer]

Originally Posted by Swacer

I would recommend cat back over axel back

why? are your pipes between the mid pipe and axle back shitty or something?

[Swacer]

Originally Posted by Seer

why? are your pipes between the mid pipe and axle back shitty or something?

No. Just with the cat back, I'm 3" the whole way to the muffler instead of 2.5" like stock.

[Seer]

Originally Posted by Swacer

No. Just with the cat back, I'm 3" the whole way to the muffler instead of 2.5" like stock.

meh, that doesn't really help ya too much unless you go FI.

[MS3DALE]

Originally Posted by Juniorv130

Hey everyone, I finally was able to join the 5th gen camaro family yesterday! 2010 Red Jewel 2SS/RS 6 speed. So pumped. Now if this crap Pittsburgh weather would break.

Anyone Have any recommended mods? Axle back exhaust is coming first...

Welcome! :smile:

[demonspeed]

Originally Posted by Seer

meh, that doesn't really help ya too much unless you go FI.

I've stood by this post for nearly a decade...

Hey guys I just got done reading a good article in the May 2005 issue of Popular Hot Rodding Magazine. The article was written by David Vizard who seems to be one of the most accredited and respected people in the automotive performance world. In the article he stated that CFM is a great way to help develop a zero loss exhaust system. For zero loss a exhaust must flow 2.2 CFM per horsepower(This means less than 1% of total power produced by the engine is lost due to back pressure.). From reading the article I think that a lot of people that see gains when going from a 2.5” exhaust system to a 3” dual system see them because the muffler on the 2.5” system didn’t flow enough for their application. David stated that per square inch of exhaust tubing there is 115 CFM of flow. So plugging some numbers into the good ole TI-89….. ((3.14 * radius^2)*115[*2 for a dual exhaust system])/2.2 = Max hp supported with zero loss

A 2.75” (stock) single system is good for a 310hp engine with zero loss…
A 3” Single system is good for a 370hp engine with zero loss…
A 3.5” Single system is good for a 503hp engine with zero loss…
A 4” Single system is good for a 657hp engine with zero loss…
A 2.25” dual system is good for a 457hp engine with zero loss…
A 2.5” dual system is good for a 513hp engine with zero loss…
A 3” dual system is good for a 812hp engine with zero loss…

Now these numbers are assuming that everything else is set up perfectly. The muffler must flow as much as the open pipe or more to get zero loss at the listed hp levels. He also states that using a muffler with a larger inlet/outlet diameter than your exhaust pipe is a great way to get more out of a smaller diameter system since the muffler flow will be able to match the straight pipe flow. Now there are many other things to consider when designing an exhaust system but I figured this would give a great foundation to build on.

Just a side note that he stated that I thought was neat... “Just as fish don’t feel the weight of water, we don’t readily appreciate the weight of air. Just to set the record straight, a cube of air 100 feet square will weigh 38 tons!”

Hopefully I’ll get some more understanding of flow in a closed space in my fluid dynamics class next semester.

- OldSchoolSS

[Swacer]

Originally Posted by demonspeed

I've stood by this post for nearly a decade...

Hey guys I just got done reading a good article in the May 2005 issue of Popular Hot Rodding Magazine. The article was written by David Vizard who seems to be one of the most accredited and respected people in the automotive performance world. In the article he stated that CFM is a great way to help develop a zero loss exhaust system. For zero loss a exhaust must flow 2.2 CFM per horsepower(This means less than 1% of total power produced by the engine is lost due to back pressure.). From reading the article I think that a lot of people that see gains when going from a 2.5” exhaust system to a 3” dual system see them because the muffler on the 2.5” system didn’t flow enough for their application. David stated that per square inch of exhaust tubing there is 115 CFM of flow. So plugging some numbers into the good ole TI-89….. ((3.14 * radius^2)*115[*2 for a dual exhaust system])/2.2 = Max hp supported with zero loss

A 2.75” (stock) single system is good for a 310hp engine with zero loss…
A 3” Single system is good for a 370hp engine with zero loss…
A 3.5” Single system is good for a 503hp engine with zero loss…
A 4” Single system is good for a 657hp engine with zero loss…
A 2.25” dual system is good for a 457hp engine with zero loss…
A 2.5” dual system is good for a 513hp engine with zero loss…
A 3” dual system is good for a 812hp engine with zero loss…

Now these numbers are assuming that everything else is set up perfectly. The muffler must flow as much as the open pipe or more to get zero loss at the listed hp levels. He also states that using a muffler with a larger inlet/outlet diameter than your exhaust pipe is a great way to get more out of a smaller diameter system since the muffler flow will be able to match the straight pipe flow. Now there are many other things to consider when designing an exhaust system but I figured this would give a great foundation to build on.

Just a side note that he stated that I thought was neat... “Just as fish don’t feel the weight of water, we don’t readily appreciate the weight of air. Just to set the record straight, a cube of air 100 feet square will weigh 38 tons!”

Hopefully I’ll get some more understanding of flow in a closed space in my fluid dynamics class next semester.

- OldSchoolSS

Now there are a lot of errors in his math.

There are factors several missing:

1. discussion of wall thickness and how that impacts the inner diameter
2. no factor on the density of the gasses or the makeup
3. no discussion of the configuration of the piping, which added to pressure losses
4. no discussion of the material type and the friction factor that changes with the material
5. I'm sure there is a Reynolds number factor in here for how the turbulent flow changes per pipe diameter.

I see the basis but don't buy into his math at all

[demonspeed]

Originally Posted by Swacer

Now there are a lot of errors in his math.

There are factors several missing:

1. discussion of wall thickness and how that impacts the inner diameter
2. no factor on the density of the gasses or the makeup
3. no discussion of the configuration of the piping, which added to pressure losses
4. no discussion of the material type and the friction factor that changes with the material
5. I'm sure there is a Reynolds number factor in here for how the turbulent flow changes per pipe diameter.

I see the basis but don't buy into his math at all

Would you be interested in further extrapolating? I'm seriously interested in taking the theory further. It's obviously well over my head, but it's certainly the "best" info we've been provided thus far.

FWIW, I'd not hesitate to go 3" when doing exhaust on a 376. Hell, I'll be going 3" on a 346.

[Swacer]

Originally Posted by demonspeed

Would you be interested in further extrapolating? I'm seriously interested in taking the theory further. It's obviously well over my head, but it's certainly the "best" info we've been provided thus far.

FWIW, I'd not hesitate to go 3" when doing exhaust on a 376. Hell, I'll be going 3" on a 346.

It would be fun to run the numbers and see how close this guys guess is with more accurate equations.

Maybe you'll have to come to the dark side of cranberry and we can run the numbers hahaha

[Juniorv130]

Thanks! Sorry to start an exhaust debate. I am replacing the bowties with the old school SS logos and have the landing pad already. I'm sure my mind will wander more.

SLP, Borla, or flowmaster? I've been around vettes with Borla forever but I can't be sure I want that sound.

Snow needs to stop.

[demonspeed]

Go with whatever sound you prefer. You could always run cutouts as well.

Oh, and never worry about apologizing for starting anything in this thread. It injects life into things now and then!

[Swacer]

Ya. It's just a friendly debate, so no apologies needed!

Debate happens frequently here. Lol

[Juniorv130]

I'm kinda partial to flowmaster outlaw. And you can get em cheaper on amazon haha!

[Juniorv130]

Any recommended sites for parts? Phastek? Summit ?