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4" cutout vs catback

Old May 29, 2015 | 10:56 AM
  #1  
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Default 4" cutout vs catback

Ok guys I'm looking for some opinions here. What I'd like to know is a 4" cutout worth much on a car like mine. All my mods are in my signature including the current exhaust setup. I see where a cutout helps some with a more restrictive setup, but I'm running 3" all the way back with a bullet style muffler in the y-pipe area. If it's only worth like maybe 5 hp then I'd say not worth it, but if it would be more like 10-15 then I'd say it might be. So what does everyone think?

Thanks
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Old May 29, 2015 | 02:10 PM
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3" single exhaust leaves considerable amount of restriction past 370hp. Combined with non-mandrel bends in the system you could easily loose more power than a FAST102 manifold would yield on that setup. You can even see in stock GM 6.2 equipped pickups utilize 3.5" single exhaust from the factory, and the restriction is that reason.

I personally run a 4" mandrel Y which supports close to 700hp before restriction. I may switch my exhaust to a 4" cutout on window switch and 3" catback for in town as it is currently overkill on the dB scale.

can refer to this chart if it helps.

http://www.exhaustvideos.com/faq/how...pipe-diameter/
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Old May 29, 2015 | 02:23 PM
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So you have a bullet muffler in the ypipe and a magnaflow catback with the crossflow style muffler on it?
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Old May 29, 2015 | 02:31 PM
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No it just has a MagnaFlow 14419 bullet muffler up in the y-pipe area, and just straight piping in the rear.

Dckmn52, that is some really interesting info. Even if the 3" exhaust is somewhat restrictive I'm still curious if the cutout will help at all even if I change nothing else
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Old Nov 2, 2015 | 06:37 AM
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Thanks for the feedback guys, but I'm bumping this again in hopes of more information. Also I need to know if a 4" cutout will even work with my setup since my FM merge is a 3" in to a 3.5" out. I'm also wondering if it will sound deeper with a 4" cutout over what I have, since I just heard my buddy's HCI setup and it sounded very deep with no rasp
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