Stainless Steel Exhaust grows more then you might think.

Johnny@MTI · 07-01-2013, 11:09 AM

I know this isn't a camaro. but we where testing our sequental T56. I threw a GoPro on the bumper to capture the noise. what i wasn't expecting was to see the exhaust grow. our engineer told me that all stainless grows when it gets heated.

family man · 07-01-2013, 11:13 AM

It must be really happy to be racing.

nyrfan · 07-01-2013, 11:37 AM

My Corsa does this. At 1st I thought the exhaust was moving until I actually figured out what it was doing.

05stram · 07-01-2013, 11:57 AM

maybe it was excited to feel the power

I noticed the holes on top aren't those holes for condensation? Shouldn't they be on the bottom?

Johnny@MTI · 07-01-2013, 12:20 PM

Quote:

Originally Posted by 05stram

maybe it was excited to feel the power

I noticed the holes on top aren't those holes for condensation? Shouldn't they be on the bottom?

this car is our test mule. we test motors and other speed related products in it. with all the engine swaps we do it never has the exhaust installed longer then a few weeks at a time. those holes are for a muffler system that we built. AMP has a very strict DB level that we must stay under.

Dznts · 07-01-2013, 01:36 PM

interesting!

nyrfan · 07-01-2013, 01:44 PM

Quote:

Originally Posted by Dznts

interesting!

Look at my thread from a few weeks back.

http://www.camaro5.com/forums/showthread.php?t=292579

Johnny@MTI · 07-01-2013, 02:01 PM

^ Glad i could help you keep your sanity hahah

sspolo · 07-01-2013, 07:01 PM

As far as I know its actually rare to find something that doesn't "grow" when heated to a certain temperature. There are charts that tell you what temperature a certain metal or other elements need to expand and how long they expand.

sspolo · 07-01-2013, 07:04 PM

An example is certain pavement and sidewalks have lines every few feet and that is for the expansion once it gets hot. When they don't have those lines, the pavement tends to crack faster since the expansion wasn't taken in consideration.

The study of this is called thermal expansion. It is a root or a phenomenon that is part of thermodynamics. In case anyone is interested on researching more about that.

Norm Peterson · 07-01-2013, 08:40 PM

Quote:

Originally Posted by Johnny@MTI

I know this isn't a camaro. but we where testing our sequental T56. I threw a GoPro on the bumper to capture the noise. what i wasn't expecting was to see the exhaust grow. our engineer told me that all stainless grows when it gets heated.

I spent nearly 30 years doing analysis of power plant piping of various metals, and they all expand quite nicely just like any other substance I can think of (even diamonds expand a little). Typically, austenitic stainless steel expands at a significantly faster rate (inches of growth per inch of length per degree F) than carbon steels, but it all grows.

Quote:

Originally Posted by nyrfan

Look at my thread from a few weeks back.

http://www.camaro5.com/forums/showthread.php?t=292579

If I'd seen it, I could have provided some information then. All exhaust systems expand, but since they may not maintain a uniform temperature over their whole length to begin with (if you aren't running very hard) and because they start cooling down the moment you shut the engine off the amounts of expansion you'd see/measure will differ. And as you noticed, cooldown (and contraction) of thinwall tubing happens fairly quickly - the fastest cooling happens right away when the difference between pipe temperature and ambient air temperature is the greatest.

The shape of the exhaust system also matters, and not only will the pipe expand rearward, but it will expand away from its cold shape depending on where and how it is hung from the car, and this will be kind of in the directions of least overall resistance. Ignoring this with a custom exhaust system routing can get you into trouble if you don't pick your support locations properly and leave enough lateral and vertical clearance, as well as allow for the rearward expansion. Y-pipes, X-pipes, and H-pipe connections can introduce additional thermal challenges.

Norm

07-01-2013, 11:37 AM	#3
nyrfan Let's go Rangers! Drives: 13' AGM 2SS/RS L99 Join Date: Jun 2011 Location: Orlando, FL Posts: 10,742 View My Garage	My Corsa does this. At 1st I thought the exhaust was moving until I actually figured out what it was doing. __________________ Soprano 4/1/00-6/14/11, Gone but NEVER forgotten! FSP tuned: 377/389

07-01-2013, 01:36 PM	#6
Dznts Anabolic Connoisseur Drives: Sold - Blown Camaro 2SS/RS LS3 Join Date: Sep 2010 Location: Oklahoma Posts: 22,094	interesting! __________________

07-01-2013, 11:13 AM	#2
family man Drives: . Join Date: Nov 2012 Location: . Posts: 1,085	It must be really happy to be racing.

07-01-2013, 11:57 AM	#4
05stram Drives: 2013 RS - 2013 2SS/RS - 1971 RS Join Date: Sep 2012 Location: West Virginia Posts: 1,027	maybe it was excited to feel the power I noticed the holes on top aren't those holes for condensation? Shouldn't they be on the bottom?

07-01-2013, 02:01 PM	#8
Johnny@MTI Drives: 99 ls1 miata Join Date: Jun 2013 Location: United States Posts: 192	^ Glad i could help you keep your sanity hahah

07-01-2013, 07:01 PM	#9
sspolo Drives: 2014 Camaro SS 1LE Join Date: Sep 2012 Location: Vancouver, WA Posts: 562	As far as I know its actually rare to find something that doesn't "grow" when heated to a certain temperature. There are charts that tell you what temperature a certain metal or other elements need to expand and how long they expand.

07-01-2013, 07:04 PM	#10
sspolo Drives: 2014 Camaro SS 1LE Join Date: Sep 2012 Location: Vancouver, WA Posts: 562	An example is certain pavement and sidewalks have lines every few feet and that is for the expansion once it gets hot. When they don't have those lines, the pavement tends to crack faster since the expansion wasn't taken in consideration. The study of this is called thermal expansion. It is a root or a phenomenon that is part of thermodynamics. In case anyone is interested on researching more about that.