#1  
Old 09-30-2021, 07:48 PM
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Default New exhaust day ... my old one joins the wall of shame!

I couldn't stand my exhaust system another minute. 2-1/2" all the way back, H pipe and AP Accelerator mufflers. Just a deep blubbery indistinct sounding system. At idle it sounded like an old police cruiser with that monotonous "mum mum mumum, mum, mum, mumum" motorboat sound to it.

I pulled into my local muffler shop, Thrush welded (2 chambers) and cash in hand. In the stall before me was a beautiful red 1969 Mustang Mach 1 fastback customer's car from Mustang Restorations getting the full treatment with Magnaflows. They cut the brand new X pipe system off and leaned it against the wall of shame and installed a 2-1/2" custom bent system with no X or H per the owners request. I asked him "No X pipe this time? He shook his head no. He fired it up and grinned from ear to ear and left. I thought damn, I hope mine sounds that good.

As the guy pulled mine in, for a moment I had a touch of remorse and thought "maybe it doesn't sound so bad after all" but I thought nah, go for it. My hillbilly bent crooked H pipe monstrosity was cut off in an instant and leaned against the wall of shame. On went 2 new custom mandrel bent mid pipes with no X or H and the Thrush welded mufflers. I also had them weld in an O2 bung. When it fired up, I just grinned from ear to ear. My choppy/lopey exhaust note had returned and every exhaust pulse sounded like a symphony to my ears.

Here's a pic of my old system and the Mustang's leaning against the wall of shame.


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Triple Black 1971 GTO. 455 + .040", Block zero decked and align honed. SD Forged rods, forged SpeedPro pistons, crankshaft oil holes chamfered, polished and balanced. 6x-8 heads with 1.77" exhaust valves, bowls blended, port matched and smoothed. Crane 284281 (234/242 @ .050 duration w. .488/.505 lift), Crane Hi-Intensity lifters, Crane 99838 springs & retainers. ProComp RPM clone w. 750 Quick Fuel Slayer, FlowTech headers, TH400 w. Hughes GM25 convertor, 3.55 BOP 10 bolt.
  #2  
Old 09-30-2021, 10:21 PM
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I'll never do an X pipe or H pipe ever again on any of my cars. The exhaust note is so much crisper.

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  #3  
Old 10-01-2021, 02:14 AM
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Come on.. Give us some pictures or a video / sound clip!!

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Old 10-01-2021, 05:28 PM
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I'll do that and post. Damn it sounds good! lol

I bought this T shirt to wear when cruising it. Just so the irony isn't lost on you, I'm pushing 70! lol


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Triple Black 1971 GTO. 455 + .040", Block zero decked and align honed. SD Forged rods, forged SpeedPro pistons, crankshaft oil holes chamfered, polished and balanced. 6x-8 heads with 1.77" exhaust valves, bowls blended, port matched and smoothed. Crane 284281 (234/242 @ .050 duration w. .488/.505 lift), Crane Hi-Intensity lifters, Crane 99838 springs & retainers. ProComp RPM clone w. 750 Quick Fuel Slayer, FlowTech headers, TH400 w. Hughes GM25 convertor, 3.55 BOP 10 bolt.
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Old 10-01-2021, 05:32 PM
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Quote:
Originally Posted by 4dblnkldude View Post
I'll never do an X pipe or H pipe ever again on any of my cars. The exhaust note is so much crisper.
Yeah, I figured that out the first time I turned the key after installing that H pipe system. I thought holy crap, I just wasted a bunch of money on a system I hate the sound of.

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Triple Black 1971 GTO. 455 + .040", Block zero decked and align honed. SD Forged rods, forged SpeedPro pistons, crankshaft oil holes chamfered, polished and balanced. 6x-8 heads with 1.77" exhaust valves, bowls blended, port matched and smoothed. Crane 284281 (234/242 @ .050 duration w. .488/.505 lift), Crane Hi-Intensity lifters, Crane 99838 springs & retainers. ProComp RPM clone w. 750 Quick Fuel Slayer, FlowTech headers, TH400 w. Hughes GM25 convertor, 3.55 BOP 10 bolt.
  #6  
Old 10-02-2021, 02:23 AM
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70? And still working on and playing with these cars? Good man!!
I can only hope I will be able to say the same in 25 years time.

I just cut the h pipe out of my flowmaster system but havent gotten the car ready to the point I can start it yet.

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  #7  
Old 10-02-2021, 09:40 AM
78w72 78w72 is online now
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what is the issue with the H or X pipes? just the sound? based on what ive read the H & for sure X pipes improve performance. on a car built for performance i will sacrifice some sound for power.

i have an H pipe & 2.5" full exhaust with flowmaster 40s on a mild 400 that sounds pretty good at idle & through the rpms. & have a 3" pypes system with X pipe & racepros on a 10.75:1 500+ hp stroker engine that sounds good (to me) at all rpms. i'm sure the X tones down the idle lope & overall sound some but on a 3" system with big 2" headers thats probably a good thing for my neighbors, passengers & helps reduce drone.

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Old 10-02-2021, 10:01 AM
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When I bought my 69 el Camino, it had a Pypes 2-1/2" exhaust with the X pipe and there mufflers.. Once I got it home and showed everybody, I went to work on that exhaust.. My 454 sounded tinny like a V-6 or a straight 6 with a single exhaust with a cheap glass pack..

I took it over to Meineke and had them make me two X pipe bypass runs. I ordered two Dyno-Max Super Turbo mufflers #17749, these are my favorite muffler. Once you get about 2000 miles on them they really sound nice!! I also pour a pint of transmission fluid into each muffler and work it all around the outer casings fiberglass.. This is an old trick that works.. The car smoked for a few miles but it goes away.. After 15,000 miles these mufflers sound so nice!! That great big block Chevy sound is back.. Those Dynomax Turbos sound just like the old big blocks with Corvair turbos..

Besides not likening the sound of the X pipe, I didn't like how it heated the floor and transmission up on a 90 degree summer day. The th400 used to get this weak first to second shift when in very hot weather. After removing the X and changing the mufflers it shifts like it was suppose to..
The interior is noticeably cooler without the X..

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Old 10-02-2021, 12:51 PM
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I seem to remember that everyone on this board loved H or X pipes a few years ago. I don't remember the "they make more power" argument - that doesn't make any sense to me, I thought it was always done for sound.

I've had headers and 3" "true dual exhaust" pipes for several years now with them exiting behind the rear wheels. It's loud, and that was the goal.

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Old 10-02-2021, 01:04 PM
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Quote:
Originally Posted by Chris65LeMans View Post
I seem to remember that everyone on this board loved H or X pipes a few years ago. I don't remember the "they make more power" argument - that doesn't make any sense to me, I thought it was always done for sound.

I've had headers and 3" "true dual exhaust" pipes for several years now with them exiting behind the rear wheels. It's loud, and that was the goal.
making more power with an X isnt really an argument & wasnt posted as one...most sources state that X pipes increase the scavenging affect of the exhaust & can increase power on an engine that can benefit from the better flow. a stock or lower HP engine probably wont see much of a gain, but the higher HP engines usually will.

lots of info out there that might make sense for you...

https://www.motortrend.com/how-to/x-...for-your-ride/

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Old 10-02-2021, 01:26 PM
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H-pipes and X-pipes do make more power. It has been tested extensively and proven on the Engine Masters show.

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  #12  
Old 10-03-2021, 09:07 AM
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Yep they'll help the power output. Even Jim Hand did a ton of testing on his wagon decades ago. Can't believe you Pontiac loyals don't remember that. Jim's a fan of them.

He found the X was the better setup and improved his car over the H. His car picked up ET and MPH, and we aren't talking about a power house, just your basic and very consistent 11 second car.

Racers looking for an edge have found they are preferred, and you'll find an X under just about every single Pure Stock and FAST class car these days too, for a reason. You can listen to dozens of them going down the track and most all of them don't sound any different than stock.

I haven't found they really change the sound a whole bunch, not enough to take notice or worry about, especially if you run the Dynomax mufflers, at least from my experience. Never found them to heat the interior or transmission either and can't even fathom how that would even be possible. The X isn't anywhere near the transmission, it's impossible to put it under there unless you have a 4x4, lol.

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Old 10-06-2021, 08:28 AM
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Depends on if your trying to be sneaky or be noticed! It is really hard to SNEAK up on someone with a 11:1 400 , gear drive, 3" pipes w/flowmaster single chambers...trying to negotiate $$$$ and who gets the hit.
VS
NO GEAR DRIVE, 2 1/2 head pipes with x pipe into 3" magnaflows out the back

Yeah...can get more takers with a few sneaky items to cover up the cam and compression (many of folks have taken that bait)

  #14  
Old 10-06-2021, 05:00 PM
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Short video ... no more H pipe! Hip hip, long live King Thrush!

https://youtu.be/jy2-6x7sJR8

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Triple Black 1971 GTO. 455 + .040", Block zero decked and align honed. SD Forged rods, forged SpeedPro pistons, crankshaft oil holes chamfered, polished and balanced. 6x-8 heads with 1.77" exhaust valves, bowls blended, port matched and smoothed. Crane 284281 (234/242 @ .050 duration w. .488/.505 lift), Crane Hi-Intensity lifters, Crane 99838 springs & retainers. ProComp RPM clone w. 750 Quick Fuel Slayer, FlowTech headers, TH400 w. Hughes GM25 convertor, 3.55 BOP 10 bolt.
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Old 10-07-2021, 12:39 PM
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Quote:
Originally Posted by 389 View Post
I also pour a pint of transmission fluid into each muffler and work it all around the outer casings fiberglass.. This is an old trick that works.. .
What is the purpose of your "Old Trick That Works"?

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  #16  
Old 10-07-2021, 08:17 PM
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As kid, we did that to glass packs but used motor oil. The idea was the flammable oil would compress and fuse the fiberglass packing making them louder. Assume the trans fluid would do the same.

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Triple Black 1971 GTO. 455 + .040", Block zero decked and align honed. SD Forged rods, forged SpeedPro pistons, crankshaft oil holes chamfered, polished and balanced. 6x-8 heads with 1.77" exhaust valves, bowls blended, port matched and smoothed. Crane 284281 (234/242 @ .050 duration w. .488/.505 lift), Crane Hi-Intensity lifters, Crane 99838 springs & retainers. ProComp RPM clone w. 750 Quick Fuel Slayer, FlowTech headers, TH400 w. Hughes GM25 convertor, 3.55 BOP 10 bolt.
  #17  
Old 10-09-2021, 02:09 PM
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My TA with 3" H pipe into 3" FLows and 2.5 tailpipes would pick up going open headers. Started getting rusty we left it off after a trans/convertor swap. Then put a 3" Dr. Gas X ,3" ultraflows and 3" mandrel tailpipes on and even with the additional weight of the exhaust it ran identical. . So fisgure running the same with an extra 40lbs or so must have picked it up.

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