|
GIL or CMI Headers for 500HP??
I'm buying a boat with a GIL headers on the 500HP (is that stock??)
And my boat has CMI, so can swap them. Not sure if there is any point. Thanks in advance for the input. |
Keep the CMI and sell the Gil!!!
|
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 |
Originally Posted by Raylar
(Post 3385542)
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 Greatly appreciated! |
Originally Posted by 2Slow4me
(Post 3387111)
Thanks for explanation, have a much better understanding of the difference's.
Greatly appreciated! |
Originally Posted by Raylar
(Post 3385542)
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 For 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 |
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 |
| All times are GMT -5. The time now is 07:10 AM. |
Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.