Flow Benches

[woollymoof]

For those out there that have a commercial / production bench, what brand is it and how much did it cost? The only brand I've heard of is a SuperFlow.

For those out there who have built their own, did you get plans from somewhere, if so where? Or did you design it yourself?

Cheers,

Kirk Veitch
Swinburne University of Technology

[woollymoof]

For those out there that have a commercial / production bench, what brand is it and how much did it cost? The only brand I've heard of is a SuperFlow.

For those out there who have built their own, did you get plans from somewhere, if so where? Or did you design it yourself?

Cheers,

Kirk Veitch
Swinburne University of Technology

[Frank]

easy flow bench

i only test airfilter, throttle, restrictor

basically you mimic steady state flow into the plenum

use a industrial vaccuum cleaner (which should pull 10" water test pressure)

then use a PITOT probe to measure/calculate dynamic pressure.. (or 2 probes.. one static, one dynamic)

keep the air speed about 50 - 60 ms^-1 at the probes (for increased accuracy).. use barometric compensation

use a big plenum volume on the test bed.. use LONG tubes, effectively damping any pulses YES pulses.. diffusers in transitory stall cause the test pressure to fluctuate

use cloured water with condese crystals (available at chemist)

use a long tube before pitot probes to ensure consistantly "fully developed flow"

expect about 75 CFM at 10" test pressure

you cant "choke" the restrictor using a shop vaccuum

a superflow SF600 flow bench can JUST do it at 38-43 inches test pressure... watch the operator at your local speed shop "spin out" when the thing chokes

to be honest.. it's more sensitive to exit diameter than anything else

use a 45mm exit diameter AT LEAST

i believe 7deg outlet is FINE (and cheaper)

regards

Frank

ps have posted previously about this matter

http://fsae.com/eve/forums?a=tpc&s=763607348&f=648600998&m=3886005121&r=6346007242#6346007242

[Frank]

just one more thing for swinbourne...

im sure you realise that a restrictor like this

http://www.users.bigpond.net.au/franko/swin.jpg

on a supercharged car..will only make slightly more power than a restrictor that is only 3 inches long...

it will serve to (slightly) reduce inlet temperature, and reduce the power consumption and hence size and weight of the blower, but I'd only expect a fraction of a horsepower more..

the choked flow rate (choked flow only being achievable on a supercharged car) is the same regardless of diffuser geometry

again i iterate, naturally aspirated cars WILL NOT CHOKE the restrictor, until they have lost a considerable amount of power; at a higher rpm than their at peak output.. of interest is the static pressure in the plenum when the engine is making maximum power..

it is this static pressure that you should use to conduct "flow bench testing" of the restrictor (if you test without the cylinder head or runners)

regards

Frank

[Frank]

"emphasize" not "iterate"

my god I've forgotten what words mean


http://fsae.com/groupee_common/emoticons/icon_frown.gif

[Daves]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>just one more thing for swinbourne...
im sure you realise that a restrictor like this

http://www.users.bigpond.net.au/franko/swin.jpg

on a supercharged car..will only make slightly more power than a restrictor that is only 3 inches long...<HR></BLOCKQUOTE>

I like the electrical tape holding the restrictor tube to the supercharger elbow. Also,the swiss cheese chain guard and supercharger belt guard add a nice touch.

[woollymoof]

That car was two years ago and is something that most at Swinny would like to forget. Anyway, thanks for your replies.

Cheers,

Kirk Veitch
Swinburne University of Technology