Exhaust Cut-Out Placement?

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Jul 24, 2007 | 10:42 AM

JFTaylor

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From: Virginia Bch VA

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St. Jude Donor '06

Exhaust Cut-Out Placement?

I had a reputable tuner tell me that the optimal placement for an exhaust cut-out is 23” down stream of the collection point of Long Tube headers.

Any Comments/Suggestions?

Jul 24, 2007 | 10:51 AM

dennis50nj

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From: Southampton NJ

Quote:

Originally Posted by JFTaylor

I had a reputable tuner tell me that the optimal placement for an exhaust cut-out is 23” down stream of the collection point of Long Tube headers.

Any Comments/Suggestions?

well in the old days we would palnt the header extensions, and wear the paint burned off too thats wear we cut it. i would think it should be the same

Jul 24, 2007 | 11:19 AM

JFTaylor

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St. Jude Donor '06

Quote:

Originally Posted by dennis50nj

well in the old days we would palnt the header extensions, and wear the paint burned off too thats wear we cut it. i would think it should be the same

That's a great test idea. May just do that. Thanks man

Jul 25, 2007 | 05:58 AM

Joe_G

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St. Jude Donor '08

There's no room up there in the tunnel for cutouts, at least the powered kind. I think if you put manual ones there they would drag on everything. We had to put mine back in front of the trans. Here's some pics to show what I'm talking about. This far back they are a sound only mod. No gain on the dyno open or closed. I'm going to try this Friday again, now that I've got a cam it might be a difference. Great mod though for the sound. I went back to stock mufflers, super quiet with the cam, all hell breaks loose when the cutouts open. REALLY loud compared to no cam open cutouts.

Jul 25, 2007 | 06:22 AM

Zig

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From: stafford country, va. Avatar: Me on turn 3 @ Bristol (The World's Fastest Half-Mile)

imo, 'cutouts' should not be placed any closer than just after the rear axle. any performance gains from a 'closer' location will not override the 'safety' concern of exhaust gasses being released under the car, where they can find their way into the cabin.

Jul 25, 2007 | 08:31 AM

ben dover

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From: When all is said and done... there is a hell of a lot more said than done. Riverside,Texas

St. Jude Donor '05 thru '26

Hey Joe, you reckon those'll fit an A6?

Jul 25, 2007 | 09:06 AM

Joe_G

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From: St. Louis, MO

St. Jude Donor '08

Quote:

Originally Posted by ben dover

Hey Joe, you reckon those'll fit an A6?

After comprehensive research, my opinion is yes, they will fit all A6's except Maroon ones. Sorry.

Truth is, I really don't know. I would have thought so but I forgot about your torque converter being in there I think about where my cutouts are.

Anyone heard if QTP got their pre-fabbed cutouts for the C6 made yet? I remember reading somewhere they were going to come out with those.

Jul 25, 2007 | 03:24 PM

tomtorchred

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From: largo florida

Quote:

Originally Posted by ben dover

Hey Joe, you reckon those'll fit an A6?

just had cut outs electric installed on my 06 a6 they look great now have to get them wired. cant wait to hear them

Last edited by tomtorchred; Jul 26, 2007 at 01:25 PM.

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Jul 25, 2007 | 04:23 PM

Joe_G

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From: St. Louis, MO

St. Jude Donor '08

Quote:

Originally Posted by tomtorchred

just had cut outs electric installed on my 06 a6 they loof great now have to get them wired. cant wait to hear them

That's great news for ol' Ben. He and I have been wondering about this for months now.

Wiring is easy, here's my write up. You will love the cutouts I bet. I do. Particularly now that I have a G5x3 in my car with stock mufflers.

It goes from whisper quiet a light....to a roaring monster. I'm a little old for this, but I do get a kick out of opening them up for the ricers "blowing their noses (blow off valves)" at me. I've surprised a few people already.

http://forums.corvetteforum.com/show....php?t=1628234

Jul 25, 2007 | 04:50 PM

#10

JFTaylor

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St. Jude Donor '06

Quote:

Originally Posted by Zig

imo, 'cutouts' should not be placed any closer than just after the rear axle. any performance gains from a 'closer' location will not override the 'safety' concern of exhaust gasses being released under the car, where they can find their way into the cabin.

Good point

Jul 25, 2007 | 04:50 PM

#11

SpinMonster

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From: Colorado Springs, CO

St. Jude Donor '08-'09-'10-'11

Quote:

Originally Posted by Joe_G

It goes from whisper quiet a light....to a roaring monster. I'm a little old for this, but I do get a kick out of opening them up for the ricers "blowing their noses (blow off valves)" at me. I've surprised a few people already.

http://forums.corvetteforum.com/show....php?t=1628234

Classic. Good post.

Jul 27, 2007 | 11:34 PM

#12

Joe_G

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From: St. Louis, MO

St. Jude Donor '08

Now that I have a G5x3 cam my cutouts matter. I got a solid 5-6 rwhp adn 6 rwtq cutouts open vs. closed. With bolt ons only they made no difference.

Here's the dyno graph, showing open on top and closed on the bottom.

Last edited by Joe_G; Jul 28, 2007 at 06:40 AM.

Jul 28, 2007 | 12:21 PM

#13

JFTaylor

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St. Jude Donor '06

Quote:

Originally Posted by Joe_G

Joe what do you have for CAT BACKS? Must be a pretty good system if you're only picking up 5 RHWP with the cut outs

Jul 28, 2007 | 01:24 PM

#14

Joe_G

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From: St. Louis, MO

St. Jude Donor '08

Quote:

Originally Posted by JFTaylor

Joe what do you have for CAT BACKS? Must be a pretty good system if you're only picking up 5 RHWP with the cut outs

Bone stock mufflers. Cat backs don't add much hp in my experience as the stock flows pretty well. I love the cutouts and having the choice of silent to crazy loud.

But the stock mufflers on a Vette are really kind of a disgrace... a performance car should have at least a little sound. I can't believe how quiet these are.

Jul 30, 2007 | 09:39 PM

#15

ssheldon

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From: portage mi

cut outs?

I have a 04 z06 with long tube headers and stainless all the way back to corsa mufflers, where do you get the motorized cut outs?

Jul 31, 2007 | 05:24 AM

#16

Joe_G

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From: St. Louis, MO

St. Jude Donor '08

Quote:

Originally Posted by ssheldon

I have a 04 z06 with long tube headers and stainless all the way back to corsa mufflers, where do you get the motorized cut outs?

QTP's. QTP is forum vendor, you can buy direct or from major catalog retailers.

Jul 31, 2007 | 08:41 AM

#17

Kevinmatt

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From: Lynchburg VA

St. Jude Donor '11

I would like to see HP gains on the C6 with headers, X-Crossover, High Flow Cats and stock mufflers. This looks like a really cool mod. I wonder if any muffler shop could do this mod. or would you take it to a tuner?

Jul 31, 2007 | 08:55 AM

#18

Joe_G

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From: St. Louis, MO

St. Jude Donor '08

Quote:

Originally Posted by Kevinmatt

I would take it to a tuner. 99% of the people who put on headers get a P0020 or P0030 code for cat inefficiency. A tune will take care of this and give you some real HP you can feel.

Here is my dyno sheet with what you mention above, plus tune and a ls2portworks.com ported intake vs. stock. As you can see it's a huge difference. I was 12.9 @ 109 stock and 11.81 @ 119 with those mods plus 3.90 gears.

Jul 31, 2007 | 08:55 AM

#19

NEEPER

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From: Benson NC

Quote:

Originally Posted by tomtorchred

just had cut outs electric installed on my 06 a6 they look great now have to get them wired. cant wait to hear them

Can you please post pictures. I want to put cutouts on my A6, but can't exactly figure out where to put them. I looked behind the axle before the stock mufflers...just doesn't look like enough room IMO. Do you still have the stock exhaust?

Bruce

Jul 31, 2007 | 10:43 AM

#20

JFTaylor

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From: Virginia Bch VA

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St. Jude Donor '06

Quote:

Originally Posted by ssheldon

I have a 04 z06 with long tube headers and stainless all the way back to corsa mufflers, where do you get the motorized cut outs?

Jegs or Summit

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