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Discussion Starter · #1 ·
Well I went and did it, I put an old 2001 Z06 H pipe I had laying around on my 2002 Z. The jingle is gone and the Z06 "Growl" is PERFECT. All I did was cut the H pipe and clamped on the 01 H pipe. The only expense was taking the old pipe to the muffler shop to have the ends of the pipe expanded in order to facilitate the "slip fit". I have heard many complaining that an X pipe is too quiet. IMO the use of the 01 pipe, which has a true 2.5 inch hole is JUST RIGHT.
 

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The '01 H pipe does not have a 2 1/2" hole if unmodified.

It has a small 1/2" hole in a baffle inside the H pipe.
 

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i put a 04 H pipe on my 01 and i have driven 300 miles since then and i still have not heard any jingle.maybe GM changed the pipe in 04 ,anyone know?
 

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Discussion Starter · #4 ·
Yes it does DJ!!!! I looked at the hole on both. The 01 had a 2.5" hole and my 02 had a dime size hole. I took the 01 h pipe off of my old 01 Z which was unmodified. The reason I had taken it off was to install an 02 pipe which did not have the pup cats.

John
 

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John is correct DJ!!
I looked at the pieces left when I had a local do the TPIS headers to catback change on my car! The H pipe was a true full-sized H.
I never thought of keeping it because I had the X-pipe and there wasn't a lot of chatter about the jingle back then!!
I have seen others that have thought about this, but just did the X instead!!
Just another good idea to put in this vast Z06 database!!

Ken
 

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The '01 OEM H pipe IS 2 1/2" OD, but it has a baffle in the center of the cross pipe that has a 1/2" hole in it and is tack welded in. The baffle is in the center of the cross pipe and cannot be seen unless the H pipe is cut apart.

'02 and later OEM H pipes had larger holes in the baffle.

If your '01 H pipe does not have a baffle in it with a 1/2" hole in it then the baffle has either been removed, fell out or it is not an OEM H pipe.

The hole size was increased in '02 to account for the higher flow OEM main CATS and loss of the Pup CATS. This larger hole caused a resonate frequency ("jingle").

This is why aftermarket H & X pipes netted more HP and a better sound when replacing all of the OEM H pipes. There was a TSB fix for the "jingle" which called for the removal of the baffle. Possibly yours had the baffle removed under the TSB.
 

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Discussion Starter · #7 ·
DJ -- I don't mean to beat this topic to death, but did you personally observe the internal H pipe baffle INSIDE of the 01 H pipe, or as your reported in a 2001 thread, "a tuner told you that the 01 H pipe had an internal baffle"? I only looked at the hole in the 01 through the main pipe and noticed the 2.5 hole. I question your assertion because I have read where others have actually "looked through the pipe" to the other side noting the full 2.5" hole. I can tell you that the installation of the pipe made my 02 sound beefier and eliminated the jingle.

John
 

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YES, we have since cut a number of scrap OEM '01 H pipes and '02 & later H pipes up. The cross pipe IS 2 1/2" OD, but inside there is a tack welded baffle occluding it in the center which has anywhere from a 3/8" to 1/2" hole in it.

The '02 and later have a larger hole, 1/2" to 3/4", in the baffle

The '01 pipe has less "jingle" but it is not a true H pipe and is only a sound attenuating device which is supposed to reduce resonance.

However true H pipe or X pipes (aftermarket with NO baffle) have better flow and thus slightly more HP but may be noisier.
 

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Discussion Starter · #9 ·
DJ,

I gotcha. Do you think by leaving the 01 pipe on will cause too much back pressure on my 02 Z or is it simply a resonance issue. I like the sound the 01 h pipe has on my Z now. No jingle. I was not expecting any HP gain and doubt that I would notice the slight HP gain an x pipe has. Thanks,

John
 

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Discussion Starter · #11 ·
Thanks for the info DJ.

John
:thumb:
 

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Discussion Starter · #13 ·
Unbelievable!!!!! What a site. PM SENT. :eek:
 

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DJWorm said:
There was a TSB fix for the "jingle" which called for the removal of the baffle. Possibly yours had the baffle removed under the TSB.
Actually, the jingle TSB replaced a large piece of the exhaust system from just after the cats to the bolt-up flanges near the diff. Yes, it included a new H-pipe, but not sure if that H-pipe was straight through or had a baffle with a bigger hole.
 
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