Head porting with Intake for test results?
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TECH Addict
Joined: Dec 2001
Posts: 2,298
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From: new england
Head porting with Intake for test results? How many people on here design and port for results with intake bolted to head? Im curious if any body ports to get good numbers with intake manifold thrown in the equation? Flow changes dramatically with it and who is to say that better results wouldnt come with making gains with it on, versus just testing with radiused entry?
Teching In
Joined: Nov 2002
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From: northern parts
Re: Head porting with Intake for test results? If I'm not mistaken, I think that Absolute Speed does do some work with the intake bolted to the head. However I personally don't think that just a cut away piece of the manifold play's the role of an actual full intake. Not saying that their stuff is'nt any good because there have been some people that have had some good result's with their product. Now if I remember some of the flow #'s off the top of my head they are in the 290's @ peak flow with an intake runner of I think 209cc. Personally I believe that the extra runner lenght play's an important role to those #'s which benefit from the intake piece and not the hole thing. But then again who know's can anyone shed some light on flow#'s back to back, with and with out the intake. Bottom line that flow # is kick *** for only a runner volume of 209cc.
TECH Fanatic
Joined: Nov 2001
Posts: 1,027
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From: KS
Re: Head porting with Intake for test results? The flow numbers that I have seen, say in short, the better the head flows the more air comes throught the intake. The ratio is not the same thought. Let's say the head flow increases 10cfm alone. Bolt the intake to it and it will only show a 3 cfm increase. What I have seen shows a head that flows in the 300's cfm will flow at least 20 cfm less with an LS6 intake.
TECH Apprentice
Joined: Aug 2002
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From: Gambrills, MD
Re: Head porting with Intake for test results? I have flow sheets from Absolute for their Stage 1x heads, both w/ & w/o an LS6 intake runner. These heads have a 208cc port.
.200 158/155
.300 216/210
.400 260/254
.450 277/268
.500 282/276
.550 286/279
.600 293/282
As you can see, the MAX differential was only 11 CFM, & the average was 6-7 CFM.
.200 158/155
.300 216/210
.400 260/254
.450 277/268
.500 282/276
.550 286/279
.600 293/282
As you can see, the MAX differential was only 11 CFM, & the average was 6-7 CFM.
TECH Enthusiast
Joined: Nov 2001
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From: Sydney Australia
Re: Head porting with Intake for test results? 
