How loud is an open downpipe?

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Oct 1, 2008 | 03:35 PM

WS6HUMMER

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From: Alexandria La.

How loud is an open downpipe?

Can I get by running an open down pipe on the street? Anyone have a sound clip? How short can a down pipe be safely? If it matters I'm running a 4" DP on a T4 flanged 76.

Oct 1, 2008 | 03:45 PM

Hennytime

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From: winter springs, fl

just do it!

Oct 1, 2008 | 03:49 PM

WS6HUMMER

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From: Alexandria La.

Quote:

Originally Posted by Hennytime

just do it!

LOL! I really want to but dont know how crazy loud it would be.

Oct 1, 2008 | 03:51 PM

SPRAYED 01

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From: Northwest side of Chicago

I dont think its going to be crazy loud. Im running a cutout kinda close to the end of the DP and its not that crazy. I drive around Downtown Chicago like that all the time. Its quiter that an n/a car running open headers.

Oct 1, 2008 | 03:53 PM

Hennytime

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From: winter springs, fl

i run a cutout on my n/a setup and its not bad, id imagine it being like an open y pipe with less rasp

Oct 1, 2008 | 03:56 PM

Mike@Diablosport

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From: Central Florida

Heres a vid of a C5 making 786 rwhp on the dyno...no mufflers, twin PTE 67s...3" pipes with turn downs.

http://www.frequencyequalsbass.com/d...chaos_dyno.mp4

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Oct 1, 2008 | 04:06 PM

Hennytime

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From: winter springs, fl

Quote:

Originally Posted by Mike@Diablosport

Heres a vid of a C5 making 786 rwhp on the dyno...no mufflers, twin PTE 67s...3" pipes with turn downs.

http://www.frequencyequalsbass.com/d...chaos_dyno.mp4

do you use a diablo tuner for that or did you use hpt or efi?

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Oct 1, 2008 | 04:25 PM

WS6HUMMER

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From: Alexandria La.

Quote:

Originally Posted by SPRAYED 01

Quote:

Originally Posted by Mike@Diablosport

Heres a vid of a C5 making 786 rwhp on the dyno...no mufflers, twin PTE 67s...3" pipes with turn downs.

http://www.frequencyequalsbass.com/d...chaos_dyno.mp4

Quote:

Originally Posted by Hennytime

i run a cutout on my n/a setup and its not bad, id imagine it being like an open y pipe with less rasp

Quote:

Originally Posted by Pro Stock John

The younger you are the more tolerable it is.

Here is a 4" downpipe with a 4" bullet that went to the rear end...

View Video on FQuick

Thanks, I think I'm gonna try it open all the time then, the vids really helped. I'm really supprised at how quiet "Dragula" was.

Oct 1, 2008 | 04:33 PM

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Frost

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From: Richmond VA

Quote:

Originally Posted by Hennytime

do you use a diablo tuner for that .....

I was gonna ask if someone else didn't

Oct 1, 2008 | 08:18 PM

#11

Roadie

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From: Breese, IL

I recently pulled my turbo stuff off and put on headers, y-pipe, and GMMG. It's a LOT louder now than it was with a T76 and open downpipe.

Oct 1, 2008 | 09:25 PM

#12

Pat-Man

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From: Georgetown, Texas

Running open downpipe as well. My WS6 with LTs, 3" ORYP, cam and cutout was much, much louder. You can always run a cutout and electric plate if you are too worried.

Oct 1, 2008 | 09:51 PM

#13

VENGEANCE

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Quote:

Originally Posted by SPRAYED 01

Its quiter that an n/a car running open headers.

+1

Im going to run an open downpipe on mine. I used to run around town with two straight pipes off the headers coming out either side. The cars going to be quieter with the turbo.

Oct 1, 2008 | 10:06 PM

#14

Reject

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From: Texas

mine is just 3 inch pipe all the way to the rear end, i love it. quiet around the block but when you get on it it's nice and loud

i know sidewayz runs a open DP right to the k member on his daily

Oct 1, 2008 | 11:22 PM

#15

frcefed98

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From: Albuquerque, NM

View Video on FQuick

Open DP and then going through a full cat back.

J

Oct 2, 2008 | 01:40 AM

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7845

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i have a full 4" back no muffler and exits in front of tire. my setup is louder then my NA stroker with duals and magnapaks

Oct 2, 2008 | 07:56 AM

#17

WS6HUMMER

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From: Alexandria La.

Thanks everyone, very helpful!

Oct 2, 2008 | 10:33 AM

#18

Silver_TransAm

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From: San Antonio, Tx

Quote:

Originally Posted by frcefed98

View Video on FQuick

Open DP and then going through a full cat back.

J

Damn what kind of cam do you have? sounds wicked.

Oct 2, 2008 | 01:03 PM

#19

1CAMWNDR

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WS6HUMMER, what is the status of your build?? If you dump the DP right under the driver's or passenger's seat it will be louder to you while driving. If you run a 4" pipe out to the tail, then it will still sound killer and will not be as loud in the cockpit.

Oct 2, 2008 | 01:10 PM

#20

Mike@Diablosport

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From: Central Florida

Quote:

Originally Posted by Hennytime

do you use a diablo tuner for that or did you use hpt or efi?

Quote:

Originally Posted by Frost

I was gonna ask if someone else didn't

That would kinda suck if we didn't use our own software, no?

Either way, yes, fully tuned with CMR and flashed with a Predator.
We should have a 4 digit project coming together soon, to be tuned with CMR as well, I will post it up when it is ready.

Here's a link to the thread in the dyno section with all mods listed.
Made 786 backed up by a 783 pull, both at 12 psi...
https://ls1tech.com/forums/dynamometer-results-comparisons/994585-786-rwhp-stock-bottom-end.html

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