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Old 11-03-2011, 05:04 PM
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JohnTVette
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Default To "X" or not to "X"

Okay, got my new headers on, but it appears that they finish up where my resonator used to be (now two straight pipes). The problem with this is that it wipes out the X pipe that was behind the cats previously.

Do I really NEED an X pipe? Or am I good without it?

Thanks in advance.
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Old 11-03-2011, 05:07 PM
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X pipe helps scavenging and to equalize bank pressure. I would HIGHLY recommend putting one in. If you can't do an X, at least do an H.
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Old 11-03-2011, 05:24 PM
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I have seen dyno sheets to prove a 25hp gain just from an x-pipe.
You want an x-pipe. If you absolutely can not do an x-pipe then at least
do the h-pipe.

You will see a performance loss without the x-pipe.

The x-pipe also increase low end torque.
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Old 11-03-2011, 05:31 PM
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That's what I was afraid of. I'll have to have one welded in where the resonator used to be. Thanks for the help.
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Old 11-03-2011, 05:36 PM
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Originally Posted by JohnTVette View Post
That's what I was afraid of. I'll have to have one welded in where the resonator used to be. Thanks for the help.
Thats what I did, don't be without an X.
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Old 11-03-2011, 05:42 PM
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also without the X or an H the chances of Drone increase
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Old 11-03-2011, 05:45 PM
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Originally Posted by Cavi View Post
also without the X or an H the chances of Drone increase
oooh....That's no good. Definitely don't want that back.
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Old 11-03-2011, 06:27 PM
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You wont lose any power without an X H or anything else. I think thats Bs.
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Old 11-03-2011, 06:34 PM
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Originally Posted by cuisinartvette View Post
You wont lose any power without an X H or anything else. I think thats Bs.
Thats right you won't lose, but you will gain with one. There is proof of gains can you show us some that there is not ? Remember you told me a tenth gain with Headers ? I got my 4/10's like I expected.

Last edited by c4speed; 11-03-2011 at 06:37 PM.
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Old 11-03-2011, 06:40 PM
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What proof? Some internet bs, a mfrs ad?

Thats not proof.


Someone wants to pay me to run straights, X H Ill do it and burn a brand new motor up on the dyno, preferrably on the track where it really matters. Ill go out on a limb and say none of its worth a buck.

Explain how adding 2 turns to each pipe with gases colliding will do better than not. I dont believe its needed, not like the exhuast is trapped in a pipe and cant get out especially on a short system like a Vettes.

Get the right head/cam and size the exhaust system properly in the first place.
Just my take.

Last edited by cuisinartvette; 11-03-2011 at 06:49 PM.
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Old 11-03-2011, 07:22 PM
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interesting...

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Old 11-03-2011, 07:39 PM
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What adds power and what doesn't, always seems to be a point of contention when it comes to exhaust. I have always been of the opinion that cat-backs and mufflers don't do a thing for power.

In my case here, I'm pretty sure I have the right cam (hot cam) and heads (ported stock) for my dual 2.5" exhaust. I have long tubes with tiny little resonators where the stock cats were once located. They eliminated the "X" pipe that was directly after the factory cats. I don't care much about how much power is lost or gained as much as I am concerned about droning. Just talked to my exhaust guy and he told me that he would weld me in an X pipe if I let him have my stock cats......deal.

I've been messing with this car for months now, I'm just ready to be done with it and start driving again.............ARGHHHHHHH
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Old 11-03-2011, 07:42 PM
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It has been proven time and again that the X-pipe design is more efficient than the H-pipe. Various tests have shown that for multiple cylinder engines the X-pipe outperforms H-pipe exhaust systems, especially as rpm increases, providing both better torque and power. Unified exhaust pipes work most efficiently with multiple cylinders because of the scavenging effect. With exhaust X-pipes the almost seamless connection between the two exhaust pipes allows sequential firing cylinders to salvage any spent exhaust gases from the combustion chamber more efficiently and creates more room in the cylinder for a fresh intake of undiluted fuel and air. When you have two exhaust pipes, as the velocity in one header tube increases, the pressure in the adjacent tube is lowered causing the exhaust to be sucked out of that cylinder. X-pipes are simply better at doing the job, especially at higher speeds.

I have seen dyno sheets to prove it. I don't have a copy they were not my sheets.
I have also seen dyno sheets in an issue of hotrod or similar magazine.

http://www.carcraft.com/techarticles...ion/index.html

this is an interesting article:
http://www.vetteweb.com/tech/0307vet...nfo/index.html

has dyno sheets showing only a 2hp gain on a vet.

My dyno guy has been dyno testing for 10 years, and racing longer.
He swears by x-pipes. Had dyno sheets that show more gains.
Personally, I think the engine matters as to how much effect it has.

Ford 302's are better with an h-pipe.

Last edited by frenchsquared; 11-03-2011 at 07:55 PM. Reason: found image
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Old 11-03-2011, 07:44 PM
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Originally Posted by JohnTVette View Post
What adds power and what doesn't, always seems to be a point of contention when it comes to exhaust. I have always been of the opinion that cat-backs and mufflers don't do a thing for power.

In my case here, I'm pretty sure I have the right cam (hot cam) and heads (ported stock) for my dual 2.5" exhaust. I have long tubes with tiny little resonators where the stock cats were once located. They eliminated the "X" pipe that was directly after the factory cats. I don't care much about how much power is lost or gained as much as I am concerned about droning. Just talked to my exhaust guy and he told me that he would weld me in an X pipe if I let him have my stock cats......deal.

I've been messing with this car for months now, I'm just ready to be done with it and start driving again.............ARGHHHHHHH
The x-pipe stopped the drown on my Camaro, but not my C10.
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Old 11-03-2011, 08:07 PM
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i will have proof hopefully next week of any gains.

out with the reasonator, and in with the x.
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Old 11-03-2011, 08:12 PM
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Youll see a gain with no resonator to an X
Straights only to an X think is what they are digging at.
Whatvever makes you feel good.
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Old 11-03-2011, 08:16 PM
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Originally Posted by cuisinartvette View Post
What proof? Some internet bs, a mfrs ad?

Thats not proof.


Someone wants to pay me to run straights, X H Ill do it and burn a brand new motor up on the dyno, preferrably on the track where it really matters. Ill go out on a limb and say none of its worth a buck.

Explain how adding 2 turns to each pipe with gases colliding will do better than not. I dont believe its needed, not like the exhuast is trapped in a pipe and cant get out especially on a short system like a Vettes.

Get the right head/cam and size the exhaust system properly in the first place.
Just my take.
QUOTE=frenchsquared;1579126469]I have seen dyno sheets to prove a 25hp gain just from an x-pipe.
You want an x-pipe. If you absolutely can not do an x-pipe then at least
do the h-pipe.
I believe him ! Why don't you ? Have you seen Dyno sheets that say otherwise?
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Old 11-03-2011, 08:36 PM
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Dyno sheets that say otherwise?
I have never seen anyone take their car with say, true duals install an X and see the claims made on this thread.

magazines, ads all that want to sell parts and pay their bills.

Could there be a gain on "someones" car, sure but some come across in these weekly threads as if they dont have an X they are giving up a bunch. They are not. Im not saying Im right but it is a real hard one to swallow. With exhaust the "more you got the more you get". Maybe a highly modded BBC or forced induction could see something plausible either way. The avg 350/383 doubtful

In the 80s the big thing was the H, everybody HAD to have one, every other mag article and muffler shop pushed them. I noticed 0 difference on my personal car Ive had a number of different motors and exhausts on. From stock to highly modded, felt nothing.

Last edited by cuisinartvette; 11-03-2011 at 08:39 PM.
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Old 11-03-2011, 08:52 PM
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You maybe right but I did see a 4/10 time difference with the OBX headers 13.2 @106 MPH. I was right about that one Pal not a tenth if I am lucky like you said. Just yanking your chain friend, I am glad we can have these fun conversations without anybody getting there feathers ruffled like some here.
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Old 11-03-2011, 09:06 PM
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I wish I could afford the dyno time. I would love to see the clear proof on my car.

A friend took his exhaust off of his Nova and ran slower with the open headers.
He was faster with the x-pipe. I know that. He would still have the time sheets.

Mild built 355 runs 14.0 all day long. Remember he is in Colorado. We get about
a 1.2 sec loss do to the altitude.

No matter, I like the sound of the x-pipe.

I also run a wideband o2 on my race car. I need an h or x to make it work properly.
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