Intake runner size vs performance
Thread Starter
TECH Regular
Joined: Mar 2006
Posts: 471
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From: Rolesville, NC
Intake runner size vs performance which would provide better performance?
1) a larger intake runner diameter for more volume of air going into the heads
or
Large diameter intake decreasing to a smaller intake to increase the air volocity
2) small intake runner diameter for faster velocity of air going into the heads
I am looking at using either AFR205s or GMPP SWGT LS6 Heads. The SWGT heads have a slightly larger volume at each lift increment then the AFR205s.
LS6 block
I have not decided on a cam yet, car is for road racing, not drag and no street use. ( not that I would want to get caught at
)
TIA
Tom
1) a larger intake runner diameter for more volume of air going into the heads
or
Large diameter intake decreasing to a smaller intake to increase the air volocity
2) small intake runner diameter for faster velocity of air going into the heads
I am looking at using either AFR205s or GMPP SWGT LS6 Heads. The SWGT heads have a slightly larger volume at each lift increment then the AFR205s.
LS6 block
I have not decided on a cam yet, car is for road racing, not drag and no street use. ( not that I would want to get caught at
)TIA
Tom
your post is a bit confusing...and i think you're confused.
there are 2 different things you're talking about
intake runner size...measured in CC. that's the "205" in the AFR 205, and the "215" in the TrickFlow 215 heads.
smaller runners build speed, and help boost power in the lower rpm range, at the expense of flow in the upper range.
then there is head flow data...measured in cfm. and that is also measured at specific lift increments.
flow is not everything...it's a compromise between air velocity from the runner size, and flow rate from the runner design.
there are 2 different things you're talking about
intake runner size...measured in CC. that's the "205" in the AFR 205, and the "215" in the TrickFlow 215 heads.
smaller runners build speed, and help boost power in the lower rpm range, at the expense of flow in the upper range.
then there is head flow data...measured in cfm. and that is also measured at specific lift increments.
flow is not everything...it's a compromise between air velocity from the runner size, and flow rate from the runner design.
Thread Starter
TECH Regular
Joined: Mar 2006
Posts: 471
Likes: 0
From: Rolesville, NC
Found this:
inlet restrictors have led turbo builders to develop carefully radiused and polished designs, whose shape is calculated using a factor called a Lemscape curve......
(source: Racecar-Engineering, August 2007, page 71)
inlet restrictors have led turbo builders to develop carefully radiused and polished designs, whose shape is calculated using a factor called a Lemscape curve......
(source: Racecar-Engineering, August 2007, page 71)
