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Old 04-29-2011, 07:52 PM   #1
Stricklinator
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Straight dual or H-pipe exhaust?

I replaced the rusted out exhaust on my 1969 C/20 with a straight dual exhaust kit from LMC (poor fit by the way, the shop had to re-bend almost everything). The shop says that they will add an h-pipe for $50. My question is whether or not I should add an h-pipe and whether $50 seems fair? I have a stock 307 with a 4-speed. Thanks
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Old 04-29-2011, 08:08 PM   #2
lsteiner72
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Re: Straight dual or H-pipe exhaust?

IMO yes H pipe is worth it and worth the $50. a x pipe would be even better but probably really hard to do with the pre made exhaust system.
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Old 04-29-2011, 08:23 PM   #3
LONG 2B LOW
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Re: Straight dual or H-pipe exhaust?

Any cross over pipe in your exhaust is always a benefit, an x pipe would definitely flow better but an h pipe will equal out the pressures in the exhaust just the same, I run an h Pipe on my 72 c20 and my 69 camaro and suggest/recommend a cross over pipe of some sort to anybody, and yes 50 dollars sounds reasonable, I'd do it
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Old 04-29-2011, 08:24 PM   #4
Mike Bradbury
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Re: Straight dual or H-pipe exhaust?

I have never seen the data between the X and H set up. The theory is the exhaust gasses from one side will help vacuum the other side. With an H pipe it seems that it would balance the sound of a dual exhaust but it might not benefit performance nearly as much as an X pipe because the exhaust gases are now trying to travel both ways in the H pipe actually slowing the flow down. Would love to see some dyno test data on the two systems.
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Old 04-29-2011, 08:26 PM   #5
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Re: Straight dual or H-pipe exhaust?

Tell them for the $50 you want two-bolt flanges so you can separate and remove the sides individually. Have them locate the flanges to one side of the crossover, so you can remove only the long side if you have to drop the trans.
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Old 04-29-2011, 09:36 PM   #6
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Re: Straight dual or H-pipe exhaust?

with a stock 307?
I say you'll never see an improvement, and it is probably pretty quiet already so noise isn't a factor...
spend the 50 on gas
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Old 04-29-2011, 09:38 PM   #7
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Re: Straight dual or H-pipe exhaust?

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Originally Posted by Longhorn Man View Post
with a stock 307?
I say you'll never see an improvement, and it is probably pretty quiet already so noise isn't a factor...
spend the 50 on gas
Agree 100%
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Old 04-29-2011, 10:10 PM   #8
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Re: Straight dual or H-pipe exhaust?

Quote:
Originally Posted by Longhorn Man View Post
with a stock 307?
I say you'll never see an improvement, and it is probably pretty quiet already so noise isn't a factor...
spend the 50 on gas
x3!

I have true duals on my 350, I prefer them over the sound of an "x" or "h" pipe set-up.
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Old 04-29-2011, 10:46 PM   #9
big_al_71
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Re: Straight dual or H-pipe exhaust?

I dont have either I went with straight duals....
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Old 04-29-2011, 10:55 PM   #10
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Re: Straight dual or H-pipe exhaust?

Ime the h pipe helps get rid of the pop and cackle sound ESP on deceleration.
I bought a jegs h pipe kit.
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Old 04-29-2011, 10:57 PM   #11
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Re: Straight dual or H-pipe exhaust?

I remember one of the mustang rags dis a shoot out on a mild 5.0
both saw improvements.
The h pipe made more of a low end difference and the x improved the numbers up top.
Neither made big gains.
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Old 04-29-2011, 11:35 PM   #12
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Re: Straight dual or H-pipe exhaust?

you didn't say what size the pipe is 2.25 or 2.50"
but the h pipe will only hurt power in that 307.. and not worth it.. unless the 307 is a stop gap to something better..
total waste in a basicly stock low compression engine that never see's north of 4000rpm
save your 50 bucks,,
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Old 04-30-2011, 09:01 AM   #13
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Re: Straight dual or H-pipe exhaust?

Quote:
Originally Posted by big_al_71 View Post
I dont have either I went with straight duals....
Me too! And I love the sound.....

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Old 04-30-2011, 04:33 PM   #14
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Re: Straight dual or H-pipe exhaust?

Thanks for the feedback everyone. I decided not to add the h-pipe as long as I have the stock 307. I figure going from a single 2" to dual 2.25" with that engine is probably overkill already.
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