GIL or CMI Headers for 500HP??
GIL or CMI Headers for 500HP??
04-24-2011 | 06:44 PM
#3
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Joined: Jan 2004
Posts: 2,777
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From: San Diego, California
Manifold is a mnaifold and long tube header is a header
Gil manifolds are manifolds with pipe risers are NOT headers, just good performance manifolds.
Which will help more will depend on which CMI header you have. If the CMI headers are of the E-top type you will not see to much difference between the two, maybe 10HP max. If the CMI's are long tube headers like Sporttube type, then this type of header can probably produce 20-25 HP more than the Gil manifold exhaust and a reasonable amount of additional torque.
Many performance boaters don't understand the difference between aftermarket exhaust manifolds or E-Top headers (with short runner passages 4-10 inch) and single pipe risers versus a true long tube header with 24-28 inch runners and a collector.
On a normally aspirated performance engines there is a definite power difference between the two in use and it is even more significant in higher power engines with deeper breathing heads, cams and intakes, where the scavenging affect of a longer tube header creates more efficiency and produces more power and torque at most rpms.
Best Regards,
Ray @ Raylar
Which will help more will depend on which CMI header you have. If the CMI headers are of the E-top type you will not see to much difference between the two, maybe 10HP max. If the CMI's are long tube headers like Sporttube type, then this type of header can probably produce 20-25 HP more than the Gil manifold exhaust and a reasonable amount of additional torque.
Many performance boaters don't understand the difference between aftermarket exhaust manifolds or E-Top headers (with short runner passages 4-10 inch) and single pipe risers versus a true long tube header with 24-28 inch runners and a collector.
On a normally aspirated performance engines there is a definite power difference between the two in use and it is even more significant in higher power engines with deeper breathing heads, cams and intakes, where the scavenging affect of a longer tube header creates more efficiency and produces more power and torque at most rpms.
Best Regards,
Ray @ Raylar
04-25-2011 | 10:34 PM
#4
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Joined: Oct 2005
Posts: 357
Likes: 7
Gil manifolds are manifolds with pipe risers are NOT headers, just good performance manifolds.
Which will help more will depend on which CMI header you have. If the CMI headers are of the E-top type you will not see to much difference between the two, maybe 10HP max. If the CMI's are long tube headers like Sporttube type, then this type of header can probably produce 20-25 HP more than the Gil manifold exhaust and a reasonable amount of additional torque.
Many performance boaters don't understand the difference between aftermarket exhaust manifolds or E-Top headers (with short runner passages 4-10 inch) and single pipe risers versus a true long tube header with 24-28 inch runners and a collector.
On a normally aspirated performance engines there is a definite power difference between the two in use and it is even more significant in higher power engines with deeper breathing heads, cams and intakes, where the scavenging affect of a longer tube header creates more efficiency and produces more power and torque at most rpms.
Best Regards,
Ray @ Raylar
Which will help more will depend on which CMI header you have. If the CMI headers are of the E-top type you will not see to much difference between the two, maybe 10HP max. If the CMI's are long tube headers like Sporttube type, then this type of header can probably produce 20-25 HP more than the Gil manifold exhaust and a reasonable amount of additional torque.
Many performance boaters don't understand the difference between aftermarket exhaust manifolds or E-Top headers (with short runner passages 4-10 inch) and single pipe risers versus a true long tube header with 24-28 inch runners and a collector.
On a normally aspirated performance engines there is a definite power difference between the two in use and it is even more significant in higher power engines with deeper breathing heads, cams and intakes, where the scavenging affect of a longer tube header creates more efficiency and produces more power and torque at most rpms.
Best Regards,
Ray @ Raylar
Greatly appreciated!
04-26-2011 | 01:46 AM
#5
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04-26-2011 | 05:47 AM
#6
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Joined: Jul 2007
Posts: 3,648
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From: Oneida Lake NY
Gil manifolds are manifolds with pipe risers are NOT headers, just good performance manifolds.
Which will help more will depend on which CMI header you have. If the CMI headers are of the E-top type you will not see to much difference between the two, maybe 10HP max. If the CMI's are long tube headers like Sporttube type, then this type of header can probably produce 20-25 HP more than the Gil manifold exhaust and a reasonable amount of additional torque.
Many performance boaters don't understand the difference between aftermarket exhaust manifolds or E-Top headers (with short runner passages 4-10 inch) and single pipe risers versus a true long tube header with 24-28 inch runners and a collector.
On a normally aspirated performance engines there is a definite power difference between the two in use and it is even more significant in higher power engines with deeper breathing heads, cams and intakes, where the scavenging affect of a longer tube header creates more efficiency and produces more power and torque at most rpms.
Best Regards,
Ray @ Raylar
Which will help more will depend on which CMI header you have. If the CMI headers are of the E-top type you will not see to much difference between the two, maybe 10HP max. If the CMI's are long tube headers like Sporttube type, then this type of header can probably produce 20-25 HP more than the Gil manifold exhaust and a reasonable amount of additional torque.
Many performance boaters don't understand the difference between aftermarket exhaust manifolds or E-Top headers (with short runner passages 4-10 inch) and single pipe risers versus a true long tube header with 24-28 inch runners and a collector.
On a normally aspirated performance engines there is a definite power difference between the two in use and it is even more significant in higher power engines with deeper breathing heads, cams and intakes, where the scavenging affect of a longer tube header creates more efficiency and produces more power and torque at most rpms.
Best Regards,
Ray @ Raylar
The raspyness added to the exhaust note is killer from a headerFor me I would keep the CMI's just for the sound. There is a guy on our lake with CMI's on a 454MPI....everyone thinks he has big power
04-26-2011 | 08:08 AM
#7
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Joined: May 2009
Posts: 3,895
Likes: 124
From: Chicago, IL; Onekama, MI
Gil's have more of an issue with reversion than does the CMI. Even if your using e-tops they will build a fair amount more torque than the Gil's and like Ray said a bit more HP. I posted several charts on here that compare most of the major manifolds/headers. Here is the link:
http://www.offshoreonly.com/forums/g...no-charts.html
http://www.offshoreonly.com/forums/g...no-charts.html
