C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

1.5" vs 1.75" headers

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Old Jun 8, 2009 | 01:02 PM
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Default 1.5" vs 1.75" headers

I'm hoping to get near the 400 hp mark with ported heads, cam and headers. My question is will 1.5" long tube headers limit my ability to hit that mark or are they good for more?
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Old Jun 8, 2009 | 01:13 PM
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400 crank or rear wheel?

If rear wheel, then yes.
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Old Jun 8, 2009 | 01:20 PM
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Only if youre talking about rwhp.
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Old Jun 8, 2009 | 01:51 PM
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I agree.

You're better off choosing between the more common 1 5/8" and 1 3/4" sizes.
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Old Jun 8, 2009 | 02:05 PM
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I've never heard of a 1.5" long tube header. Who makes them?
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Old Jun 8, 2009 | 02:07 PM
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Yeah my bad, I meant 1 5/8 not 1 1/2. So what your saying the 1 5/8 should be ok. RWHP is my goal but if I understand that correctly the crank would need to be around 440 hp or 10% loss on a auto. Is this correct?
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Old Jun 8, 2009 | 02:25 PM
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Originally Posted by tuffLUV
Yeah my bad, I meant 1 5/8 not 1 1/2. So what your saying the 1 5/8 should be ok. RWHP is my goal but if I understand that correctly the crank would need to be around 440 hp or 10% loss on a auto. Is this correct?
1 3/4 will be better. Also in the future when you add more mods to reach 450, you'll be covered.
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Old Jun 8, 2009 | 03:54 PM
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Old Jun 8, 2009 | 05:37 PM
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What size motor? What rpm range you looking to turn and what heads you using?

1 3/4 generally is preferred for that power level. If your using heads with a big exhaust port, get the 1 3/4 since a 1 5/8 wont cover the port. AFR heads are like this... the exhaust port wants/needs a 1 3/4 to properly cover the port.
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Old Jun 8, 2009 | 05:41 PM
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I was looking to get a set of ported heads from cuisinartvette and the headers from SW. The SW headers are 1 5/8 for the non ZR1. It's for an LT1.
I was also looking at Melrose 1 3/4 but couldn't get a quote on just headers and cats, don't need the cat back pipes.

Last edited by C4fan; Jun 8, 2009 at 05:49 PM.
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Old Jun 8, 2009 | 11:52 PM
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Originally Posted by tuffLUV
I was looking to get a set of ported heads from cuisinartvette and the headers from SW. The SW headers are 1 5/8 for the non ZR1. It's for an LT1.
I was also looking at Melrose 1 3/4 but couldn't get a quote on just headers and cats, don't need the cat back pipes.
Talk to Ron (Cuisinart) and see what he recommends. He's the one doing the porting anyway.
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Old Jun 9, 2009 | 10:13 AM
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Originally Posted by GREGGPENN
Talk to Ron (Cuisinart) and see what he recommends. He's the one doing the porting anyway.
he knows his stuff.
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