20v mani largeport-smallport flow bench tests

[ibizacupra]

off an interesting thread over on vortex. here>> http://forums.vwvortex.com/zerothread?id=2604980

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Finaly got around to flow testing the the two intake maifolds.

The APR intake manifold flows 262 at the runner closes to the TB to 256 for the runner furthest away from the TB

The stock Small Port Manifold flows 172 CFM average

Both done @28" of vacuum.

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APR mani is largeport and has 75mm t'body. Stock mani has 59mm t'body

Ongoing flowbench testing of other intake manifolds on this thread here>> http://forums.vwvortex.com/zeropost?cmd=tshow&id=2953254

 

[myk3]

nice info, as i have the aum engine the ports are smaller. how much power and how much faster would the turbo spool with a larger port manifold and a port and polished head. i am considering doing it, i just dont know if i can justify the cost.

cheers

 

[Ruddmeister]

I was following that thread, interesting stuff

I completley understand why Bob Q sidestepped the testing etc

Cue 20 pages on Vortex of people saying Bench flow doesn;t replicate actual car temps and pressures etc

 

[Yumann]

I was following that tread aswell makes for good reading.

Without doubt there are gains to be had with largeport and r32 TB.

I'm sure bill will share some figures soon.

 

[ibizacupra]

I was following that tread aswell makes for good reading.

Without doubt there are gains to be had with largeport and r32 TB.

I'm sure bill will share some figures soon.

I know there are gains in airflow... as shown by my apparent lack of fueling now for no other change. Mine was largeport before also tho, dual plenum mani stock TB.

There were claims from some vortexers on APR's new intake mani, but when you drilled down asking and asking, it was very apparent the changes were not simply mani, but mani + 75mm TB AND porting a smallport head to close as they could get to largeport runners to suit the APR mani. More than one change.

Was it mani, was it 75mm TB, was it porting of head to largeport? - my 2p being it was combination of all of them.

the flowbench results will be intresting in making sense of what they will relate to in engine terms.. add to that some guys on 250whp cars, some with 350whp cars and some with >450whp cars and you will get different results depending on these other specs.. again my 2p on this being those with more power have more to gain, with some cross over between smallport and large throttle in benefit terms.

all good stuff tho.