Dyno comparison of 3.0/3.5" exhaust vs. 3.5" straight pipes
06-12-2020 | 08:27 PM
#46
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Here is a quick idle clip of the straight pipes.... It's relatively quiet unless you are standing straight behind the car where the sound is amplified as both exhaust pipes angle slightly toward the center.
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LinwoodM (04-16-2022)
06-12-2020 | 09:15 PM
#48
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However, I am happy to be corrected.
06-12-2020 | 09:21 PM
#49
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Here is a quick idle clip of the straight pipes.... It's relatively quiet unless you are standing straight behind the car where the sound is amplified as both exhaust pipes angle slightly toward the center.
https://www.youtube.com/watch?v=LJ1tI8UI47Q
https://www.youtube.com/watch?v=LJ1tI8UI47Q
06-13-2020 | 02:24 AM
#51
Burning Brakes
Joined: May 2016
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I was under the impression that the thermal properties of ti were very good for 'exhaust only components' and not so good for headers in that it did not expand as much as stainless when it got hot, thereby making it less prone to cracking.
However, I am happy to be corrected.
However, I am happy to be corrected.
06-13-2020 | 07:47 PM
#54
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The only reason we made it out of Ti is because I did not see an issue with cracking on short straight pipes and I wanted the tail pipes to be light so as not to necessitate bracing. It could easily be made out of standard SS304 x 0.065 which is used for pretty much all automotive exhaust systems but needlessly heavy. The way to go on this is to manufacture it out of Aerospace SS321 x 0.035 wall tubing. It is used in turbocharged GA aircraft exhaust systems that see 1300F EGT if not more. Pound for pound 321 x 0.035 is actually lighter than Inconel. Our exhausts do not see the temperatures what would make Inconel a necessity.
What would be fantastic is to have a full 3.5" tip to tail flow thought exhaust and also have the option to V-band in a pair of straight pipes of the same modular recipe I'm running. This would make it a simple 5 minute process to go from a full exhaust to straight pipes for the track. Something tells me John at Speedtech may have something up his sleeve in the near future...
What would be fantastic is to have a full 3.5" tip to tail flow thought exhaust and also have the option to V-band in a pair of straight pipes of the same modular recipe I'm running. This would make it a simple 5 minute process to go from a full exhaust to straight pipes for the track. Something tells me John at Speedtech may have something up his sleeve in the near future...
06-14-2020 | 01:17 AM
#55
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I register it every year as the tag is only about $50 but I don't drive it on the street, maybe in a pinch once or twice per year. Car is transported via trailer normally. I have a set of E88s with NT01s on it in case I need to drive it on the street but I have never actually mounted then on the car. I'm sorta committed to slicks...Oh well...
06-14-2020 | 09:23 PM
#56
Instructor
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I’m catching up here since I’ve been spending time at the track ever since quarantine lifted. Nothing like coming back to the forum to a fresh Powdrhound post.
One day I have to see this car in person.
Personally, my weekend included installing my new Rennline battery mount with Odyssey 680. Meanwhile John was calculating the speed of sound and engineering a new exhaust system. 😉
One day I have to see this car in person.
Personally, my weekend included installing my new Rennline battery mount with Odyssey 680. Meanwhile John was calculating the speed of sound and engineering a new exhaust system. 😉
06-15-2020 | 01:43 PM
#59
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Any chance you could share how you calculated the length of the 1/4 wave tubes? Looking at the physics, I'm curious what how you calculated the speed of sound, given it changes dramatically with temperature. Also, do you have any idea how notchy the anti drone properties are? Or does it have a decent bandwidth across an rpm range?
v = 331 m/s + (0.6 m/s/C)•T
where T is the temperature of the air in degrees Celsius. Using this equation to determine the speed of a sound wave in air at a temperature of 15 degrees Celsius yields the following solution.v = 331 m/s + (0.6 m/s/C)•Tv = 331 m/s + (0.6 m/s/C)•(15 C)
v = 331 m/s + 9 m/s
v = 340 m/s
v = 331 m/s + 9 m/s
v = 340 m/s