The Feb'08 HR had an interesting test of the RPM Air Gap, Vic Jr, and Super Vic small block chevy intakes. Although the jist of the conclusion was porting your manifold can get you 13-14hp on a 600hp sbc, I was pretty surprised by how well the RPM AG did.
My brother and I have been running the same drivetrain combo (427 sbc + TH400), with the main differences being he's 300lbs lighter, has a Vic Jr (I got an RPM AG), a down-leg 750 Speed Demon double-pumper (I got a 750 annular vacuum secondary SD), 210 AFRs (I got 210 Eliminators), and his cam is 110 LSA (I'm 112 - 3318/3319 CC lobes). My best track run (w/o N2O) was 11.8 at 114, but I easily lost 0.3-0.4sec in my crappy 2.2sec 60'. My brother has run 11.0 at 120mph (w/o N2O). I was thinking the lost 6mph could be due to the intakes, but the HR article suggests it wouldn't be worth it below 6500.
The thing in the article that surprised me was how much cfm the air gap gained when run with the heads (it flowed more than the Vic Jr). I was a little confused why the ported version only picked up 16cfm with the heads, when it gained 75 cfm w/o heads.
Does anyone think there would be a noticable improvement switching from an RPM AG to a single plane in a car that doesn't go over 6500rpm? Think porting the intake is worth it?
My brother and I have been running the same drivetrain combo (427 sbc + TH400), with the main differences being he's 300lbs lighter, has a Vic Jr (I got an RPM AG), a down-leg 750 Speed Demon double-pumper (I got a 750 annular vacuum secondary SD), 210 AFRs (I got 210 Eliminators), and his cam is 110 LSA (I'm 112 - 3318/3319 CC lobes). My best track run (w/o N2O) was 11.8 at 114, but I easily lost 0.3-0.4sec in my crappy 2.2sec 60'. My brother has run 11.0 at 120mph (w/o N2O). I was thinking the lost 6mph could be due to the intakes, but the HR article suggests it wouldn't be worth it below 6500.
The thing in the article that surprised me was how much cfm the air gap gained when run with the heads (it flowed more than the Vic Jr). I was a little confused why the ported version only picked up 16cfm with the heads, when it gained 75 cfm w/o heads.
Does anyone think there would be a noticable improvement switching from an RPM AG to a single plane in a car that doesn't go over 6500rpm? Think porting the intake is worth it?
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