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What did u do to get rid of "rasp" sound

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Old 05-02-2014 | 10:53 AM
  #41  
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Originally Posted by LQ4-E39
I am running into some rasp with my new exhaust setup on my swap and want to get rid of it.

6.0L LQ4
CTS-V (1st Gen) OEM manifolds
dual 3" stainless piping to an X-pipe under the rear seat
Right (passenger) branch after the X-pipe is straight piped out the back with a currently closed cutout dump
Left (driver) branch after the X-pipe goes to the OEM BMW muffler which has a factory Helmholtz resonator. Closed cutout between the X-pipe and the BMW muffler.

Raspy on cold start around 1.5K, and 2.5K.

Would one of these in each of my straight lengths before the x-pipe reduce the rasp? I believe I have the room for it.

http://www.summitracing.com/parts/wlk-24248/overview/
FYI all, I had these welded in after the X-pipe and before the OEM mufflers, and it eliminated the rasp completely. very happy with them for the price, all stainless construction, low profile.
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Old 05-03-2014 | 02:25 AM
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Most of the time the "rasp" that you get from an ory style exhaust is from the quality of the merge itself. Most ory just jam one pipe into the other at a bad angle. That results in a y that doesn't flow all that well because the exhaust pulses from each pipe are bouncing off one another and creating turbulance. This is where the rasp comes from. I almost guarantee if you put a good quality merge in like the Flowmaster merge it will eliminate your problem.
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Old 05-03-2014 | 10:18 AM
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no mufflers, LT headers, ORY and straight out the back.

loud as HELL but there's no rasp lol
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Old 05-03-2014 | 11:16 AM
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This is what I did before I went to TD's.

Pay particular attention to what I did to the TSP ORY

https://ls1tech.com/forums/generatio...tall-pics.html
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Old 05-03-2014 | 01:26 PM
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Why couldn't a guy buy 2 stock v6 cat back pipes to make duals? I know they are smaller than 3". 2 1/2? Or 2 1/4? Prob either one would work. Has anyone tried that?
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Old 05-03-2014 | 01:49 PM
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Originally Posted by dr_whigham
This is what I did before I went to TD's.

Pay particular attention to what I did to the TSP ORY

https://ls1tech.com/forums/generatio...tall-pics.html
pretty much what I did with mine except I used a 3.5"x9" dynomax bullet instead with an electric cutout right after the muffler. Sounds awesome and has absolutely no rasp at all. Its as rasp free as my old TSP true duals with sweet thunders with turn downs. Its just as loud but can be quiet as stock with the flip of a switch.
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Old 05-03-2014 | 09:43 PM
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Dynomax part # 47696 2.5" I pipe. For sup 93-95 camaro. Mandrel bent. Like $80. I think I'm getting 2.
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Old 05-04-2014 | 12:27 PM
  #48  
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Originally Posted by JRENIGAR
pretty much what I did with mine except I used a 3.5"x9" dynomax bullet instead with an electric cutout right after the muffler. Sounds awesome and has absolutely no rasp at all. Its as rasp free as my old TSP true duals with sweet thunders with turn downs. Its just as loud but can be quiet as stock with the flip of a switch.
Another vote for using the dynomax mini-bullet ^^. I have the TSP ORY followed by a Flowmaster dual 3" in/3.5" out merge. I welded the 3.5"x9" dynomax to that followed by a Borla XR1 3.5" in/3/5" with a turndown welded to the Borla. perfect length for a dump at the axle. Zero rasp at any rpm, sounds very deep at idle, and screams at full throttle.
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Old 05-05-2014 | 01:11 AM
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Originally Posted by GMPPDEALER
Why couldn't a guy buy 2 stock v6 cat back pipes to make duals? I know they are smaller than 3". 2 1/2? Or 2 1/4? Prob either one would work. Has anyone tried that?
I thought about this and it's totally doable for $40.

I just couldn't find two v6 cars around me so I went dumped before axle route.
Last edited by bad_408_vert; 05-05-2014 at 01:18 AM.
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Old 05-05-2014 | 11:59 AM
  #50  
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This should kill all rasp in lt ory into gmmg.

What did u do to get rid of "rasp" sound-forumrunner_20140505_105912.png
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Old 05-05-2014 | 12:28 PM
  #51  
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I have a custom 2.5 y pipe from a muffler shop ingo a slp 2 an that was realy bad. But i ordered one high flow cat an put it right in front of the slp muffler an that took care of it.. then took off my tail pip an pit dump right before the axel. Sound bad ***.
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