Stainless exhaust systems

[USAZR1]

Any of you running a full stainless exhaust system on your PT'er? I've been talking to Roger Witham of Texas Quality Exhaust about building me a one-off system for my car. Want to cut the bumper where the license plate currently resides and run a pair of double-d tips ala Viper.
He built a polished 3" stainless centermount system w/X-pipe for my Callaway ZR-1 that looked great and produced some good numbers. Am wanting to duplicate that system for my 69. I've got the extra funds right now but sure hate to spend so much on an exhaust system,though. What components did you use on your car?

[Overkill]

I am currently getting mine together. I bought a bunch of 90* and 45* bends from SPD Exhaust in Rancho Cordova, CA. along with 10 feet of straight. I am also using V-band clamps on it so that I can run normal headers now and then switch to the twin turbo setup once I get the new engine built. I am also using V-band clamps after the mufflers so that I can get the tail pipes installed easier. I haven't picked out the mufflers yet, but am thinking about using Magnaflow stainless mufflers. I really need to figure out my rear suspension before I get to much of it done so that I can make sure that everything will fit.

Michael

[USAZR1]

I put my car on a lift this afternoon to get some measurements for a Rick's stainless tank. While under the car,it became apparent a centermount exhaust system with the tips coming out the rear is going to be a tough problem to solve. Looks like a side exhaust coming out the rocker panel ala Ford Lightning is the way to go.
Brian Cichocki did a nice rendering of my car that featured a cool side exhaust. If anyone wants to post the photo,I can email it to them.

[ProTouring442]

Not that I am the expert... just remember that a stainless exhaust will grow in length. A lot! A good 1 1/2 to 2 inches for a full length system. You'll have to make sure your mounting system leaves room for this expansion.

[USAZR1]

From the Stainless Works faq page: Does stainless expand a lot more than aluminized steel. I have heard that a stainless system will grow 1 ½” in length when it gets hot. Is this true?

In a word, NO! If stainless systems expanded as much as some old wives tales would lead you to believe, then how would so many OEMs use it and not have problems? The key is to look at a property of the material called the coefficient of thermal expansion (COTE-Geek terms for how much the material will grow when it gets hot). For mild steel the COTE is:
6.3 X 10-6

For stainless, the COTE is:

9.4 X 10-6

· So, to calculate the change in length we use the following formula:

=(COTE)(Length of component)(change in temperature)

Looking at an exhaust system that is 84 inches long, and whose temperature will change 600 degrees F, on average, for mild steel:

change in length=.3157 inch.

For stainless: =.473 inch

As you can see, the difference over a 7-foot long exhaust system is negligible (it amounts to .0019 inch per inch).

[ProTouring442]

From the Stainless Works faq page: Does stainless expand a lot more than aluminized steel. I have heard that a stainless system will grow 1 ½” in length when it gets hot. Is this true?

In a word, NO! If stainless systems expanded as much as some old wives tales would lead you to believe, then how would so many OEMs use it and not have problems? The key is to look at a property of the material called the coefficient of thermal expansion (COTE-Geek terms for how much the material will grow when it gets hot). For mild steel the COTE is:
6.3 X 10-6

For stainless, the COTE is:

9.4 X 10-6

· So, to calculate the change in length we use the following formula:

=(COTE)(Length of component)(change in temperature)

Looking at an exhaust system that is 84 inches long, and whose temperature will change 600 degrees F, on average, for mild steel:

change in length=.3157 inch.

For stainless: =.473 inch

As you can see, the difference over a 7-foot long exhaust system is negligible (it amounts to .0019 inch per inch).

Not to be argumentative, but the wear marks on the rear most brackets of the exhaust onn my Dad's '56 clearly show a good 1 to 1 1/4 inch linear wear mark. Now I did go look at this after I left my last post, and as you can tell my memory had exagerated things. Still, the wear is there and it is a good 1 to 1 1/4 inches long! I am guessing that the exhaust might just be shifting forwards and back, but since it is attached to the engine pretty solidly...

[USAZR1]

I've run stainless exhaust systems on both my ZR-1's for years and have never seen any evidence of the expansion you mention. I've spent many years on the Corvette Forum,the largest such site on the WWW,and have never read nor heard of such a thing there,either.
A 1.5" growth in an exhaust system would be practically unheard of,Bill.
It would be almost impossible to keep it on the car,if it was doing that.

[scogin918]

I'm running Stainless on my car but I ordered 1 7/8" weld up kit from www.Kookscustomheaders.com. 12 j-bends, flanges, pre-made collectors with "velocity spike" to reduce turbulence, and bungs for the O2 sensors. pretty fair price.