Official Show your Birds thread!

**Too Fast** · 06-15-2011, 03:38 AM

I gained cleanance with my Hookers/ORY. I can fit a coke can upright under the headers with about 1/8'' to spare, and can almost fit it under my ORY. Car is not lowered, tho, and we have no emissions checks.

**Ant71130** · 06-16-2011, 04:49 AM

Originally Posted by lees02ws6

Tough to out run a radio, but I was also concerned with clearance. Clearance concerns are also the reason the exhaust is 2.5", instead of 3".

Lol I know, was just joking. The whole exhaust is 2.5? Wasn't it factory 2.75"? Mine's lowered quite a bit with a 3" and I don't really have too many clearance issues. Just need to drive slowly and at an angle over some things. Certainly wouldn't warrant the performance/sound decrease for me to change

Originally Posted by Too Fast

I gained cleanance with my Hookers/ORY. I can fit a coke can upright under the headers with about 1/8'' to spare, and can almost fit it under my ORY. Car is not lowered, tho, and we have no emissions checks.

Yeah but lowering to most people takes precedent over even SFCs lol

**lees02ws6** · 06-16-2011, 05:48 AM

Originally Posted by Ant71130

Lol I know, was just joking. The whole exhaust is 2.5? Wasn't it factory 2.75"? Mine's lowered quite a bit with a 3" and I don't really have too many clearance issues. Just need to drive slowly and at an angle over some things. Certainly wouldn't warrant the performance/sound decrease for me to change

Yeah but lowering to most people takes precedent over even SFCs lol

Yes, the stock system is 2.75". 3" would sound better, here's some informative info from that other ls1 site:

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

**Ant71130** · 06-16-2011, 12:16 PM

Interesting, is yours a dual system?

**Thunda** · 06-16-2011, 05:39 PM

Good story, and great info for us all.

**z-maro** · 06-18-2011, 04:25 PM

Here is my new Hawk

**Ant71130** · 06-18-2011, 10:04 PM

Originally Posted by z-maro

Here is my new Hawk

Nice lookin' car man. Take care of her.

**2001camaroSS** · 06-20-2011, 06:11 AM

Originally Posted by z-maro

Here is my new Hawk

looks very clean. nice find!

**silverWS6** · 06-20-2011, 09:48 PM

Originally Posted by z-maro

Here is my new Hawk

Alright, fuck it.

I'm selling all my cars and buying one of these!!

**2001camaroSS** · 06-21-2011, 06:55 AM

Originally Posted by silverWS.6

Alright, fuck it.

I'm selling all my cars and buying one of these!!

Do it!

**024mula** · 06-22-2011, 04:10 PM

Originally Posted by z-maro

Here is my new Hawk

NICE! Very Nice.

**j nix** · 06-22-2011, 04:44 PM

Originally Posted by silverWS.6

Alright, fuck it.

I'm selling all my cars and buying one of these!!

Get rid of your WS6? Are you crazy?

**z-maro** · 06-22-2011, 06:18 PM

Thanks everyone!

**Thunda** · 06-23-2011, 01:12 PM

http://photobucket.com/Thunda01

**Too Fast** · 06-23-2011, 02:15 PM

Looks great Thunda! Is that a '75 also?

**Obsession** · 06-24-2011, 02:07 PM

Originally Posted by Too Fast

Looks great Thunda! Is that a '75 also?

I think it is a "76" the "75" had black rubber bumbers very nice I has a "73" 455 SD

**Too Fast** · 06-25-2011, 02:04 PM

Is the '73 a SD Trans Am or Formula? Is it M4? Saw some nice 1st gen drag Firebirds at a Nostalgia drag race today in Muncie (ever heard of a Muncie 4 spd lol) IN today. As well as some early 2nd gens and Arnie the Farmer Beswick was there with Tameless Tiger.