H - Pipes

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Doppleganger

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Found that a common 3" T pipe junction is about unobtanium. Only place I could find one in stainless (or anything else for that matter) is from a place in the UK or Germany....for about $50 ea plus the ride. Crazy.
 

rt66paul

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But really.... even a 2" crossover pipe on the 3" setup would work much better than nothing. We called it an equalizer tube back in the day and it uses both muffs for a smoother sound and is supposed to allow it to wind up faster.
 

talltidefan

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2 1/4" turned out before rear axle on Bessie, 86 k5 Silverado. I went with headers when I swapped to the roller 350 vortec. Not much room under there, and headers do more than any type of crossover. $.02
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Talltidefan
 

yevgenievich

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As a random note, c6 corvette had an h pipe until 2008 when they switched to x pipe at the same time as the motor size was bumped up
 

Poppy 87

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Awesome! I call my 87 R10 Bessie too!

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hirschdalechevy

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Just put new exhaust on my blazer,

1, have headers , 2 1/2 inch pipe, moroso spiral flows, no h pipe , just over the back axle , 3 inch x 18 inch long tips.
Sounds like a drag car from idle to any rpm you choose to be at. So that was getting a bit old on the highway and attracted to much attention up in the hills so I needed to tone it down a bit.

2, same headers , 2 1/2 pipe, borla pro xs mufflers , added an H pipe , just over the back axle , reused same tips.
Now its way quieter and idle and at highway speed but still sounds tuff when you are on it. Has a tick of drone at low rpm cruise but not bad.

The H pipe is just past the t-case at a 45 degree angle above the drive shaft.

My engine is a new 357 horse 350 with vortec heads and 215/223 duration , 473 lift , 108 lsa , hyd. roller cam and 9 to1 compression. It sounds a lot more tame everywhere , (H pipe and a packing muffler vs. a chamber muffler) but as far as performance goes there is no seat of the pants gain at all that I can feel.
 

Poppy 87

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I'm going to do an X-pipe when the new motor goes in.

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Green79Scottsdale

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I've HEARD the 22" back from the header was good, and that you should spray paint from the header back about 2.5'; where the paint doesn't burn THAT'S where you put the H.

What do I know?

You may be on to something and you don't realize it. Back when my dad and his buddies were drag racing, they would use a wax pencil and put a line on the exhaust. The transition point of that wax line melting is where they would open up the exhaust. Of all the testing they did, when they opened up the exhaust, and by "opened up" I mean cut the exhaust off there, at that melting point, they ALWAYS ran their best times. Their philosophy is that hot gases and their "volume" are helping to scavenge the exhaust gases from the other cylinders, as they are at a higher pressure and are moving towards the lower pressure of the open end of the exhaust. At that point where the wax pencil doesn't melt it the point that the exhaust gases have cooled and condensed to the point that they now need to be pushed to the exhaust exit. Hence why the engine masters 2.5" vs 3" test gave the results it did. And also why countless dyno testing on open headers vs a collector extension almost always favor the extension. I would like to see a dyno test that puts an H or X pipe at that point. But, I have never seen a dyno test that followed the philosophy I just presented.

Hope you all followed that. Relevant or not, that's my .02
And not that I necessarily need to vet these guys, but they were all serious gearheads that did everything from drag racing to truck pulling (alcohol burning L88 big blocks) to snowmobiles, and all highly successful winning programs. One currently has a boat with twin EFI 572 big blocks making 850hp each.
 

bucket

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Close.

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That's good radiator placement right there. Cools the engine and keeps you warm too.
 

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