how to calibrate my bench with pts orifice plates

Orifice Style bench discussions
1960FL
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Joined: Fri Jan 08, 2010 10:36 pm
Location: Maryland

Re: how to calibrate my bench with pts orifice plates

Post by 1960FL »

This shows the difference in the designs SF600 Rotating orifice at a 45° in chamber and the SF1020 Horizontal Fixed orifice I truly believe the issue with the high flow falling off on the 600 is due to nan laminar flow through the orifice.

Rick

PM308 I do not think i would fool with your calibration any further but explore the issue with all motors and the pressure taps to see if you can better that issue.
Chad Speier
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Joined: Mon Jul 26, 2010 7:48 pm
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Re: how to calibrate my bench with pts orifice plates

Post by Chad Speier »

1960FL wrote:This shows the difference in the designs SF600 Rotating orifice at a 45° in chamber and the SF1020 Horizontal Fixed orifice I truly believe the issue with the high flow falling off on the 600 is due to nan laminar flow through the orifice.

Rick

PM308 I do not think i would fool with your calibration any further but explore the issue with all motors and the pressure taps to see if you can better that issue.
I totally agree with this Rick!!!
larrycavan
Posts: 235
Joined: Tue Mar 09, 2010 9:46 pm

Re: how to calibrate my bench with pts orifice plates

Post by larrycavan »

Chad Speier wrote:
1960FL wrote:This shows the difference in the designs SF600 Rotating orifice at a 45° in chamber and the SF1020 Horizontal Fixed orifice I truly believe the issue with the high flow falling off on the 600 is due to nan laminar flow through the orifice.

Rick

PM308 I do not think i would fool with your calibration any further but explore the issue with all motors and the pressure taps to see if you can better that issue.
I totally agree with this Rick!!!

Didn't your DIY bench have the orifice plate at an angle?
Larry C

http://www.cavanaughracing.com
Chad Speier
Posts: 139
Joined: Mon Jul 26, 2010 7:48 pm
Contact:

Re: how to calibrate my bench with pts orifice plates

Post by Chad Speier »

larrycavan wrote:
Chad Speier wrote:
1960FL wrote:This shows the difference in the designs SF600 Rotating orifice at a 45° in chamber and the SF1020 Horizontal Fixed orifice I truly believe the issue with the high flow falling off on the 600 is due to nan laminar flow through the orifice.

Rick

PM308 I do not think i would fool with your calibration any further but explore the issue with all motors and the pressure taps to see if you can better that issue.
I totally agree with this Rick!!!

Didn't your DIY bench have the orifice plate at an angle?
The first bench, yes. The one I have now, no..
larrycavan
Posts: 235
Joined: Tue Mar 09, 2010 9:46 pm

Re: how to calibrate my bench with pts orifice plates

Post by larrycavan »

Didn't your DIY bench have the orifice plate at an angle?
The first bench, yes. The one I have now, no..
OK...in comparison to Darin's bench, which of your 2 DIY benches did you have dialed in so close to Darin's bench? The MSD style or the new bench?
Larry C

http://www.cavanaughracing.com
Chad Speier
Posts: 139
Joined: Mon Jul 26, 2010 7:48 pm
Contact:

Re: how to calibrate my bench with pts orifice plates

Post by Chad Speier »

larrycavan wrote:
Didn't your DIY bench have the orifice plate at an angle?
The first bench, yes. The one I have now, no..
OK...in comparison to Darin's bench, which of your 2 DIY benches did you have dialed in so close to Darin's bench? The MSD style or the new bench?

The new..

However I have a curve with the his SF w/Audie vs manometers. This is with my new calibrated numbers for the bench.

The .500 number worries me.

LIFT ME/HIM

.200 148/152
.300 194/193
.400 241/244
.500 278/284
.600 298/300
.700 305/305
.800 309/306
.900 310/309
larrycavan
Posts: 235
Joined: Tue Mar 09, 2010 9:46 pm

Re: how to calibrate my bench with pts orifice plates

Post by larrycavan »

:lol: don't worry too much.... It will match some 600..somehwere :D
Larry C

http://www.cavanaughracing.com
PM308
Posts: 5
Joined: Sat Jan 07, 2012 10:57 am

Re: how to calibrate my bench with pts orifice plates

Post by PM308 »

thanks for putting time and effort in to helping me guys, much appreciated

the motor situation is what bothers me as maybe certain combinations may have an extra motor on possibly showing a higher number at one lift, this is something i will work on

is there any need to check flow with the head stand, the way i see it is that it just adds another variable when trying to compare to other benches as not all bore diameters will be the same.
larrycavan
Posts: 235
Joined: Tue Mar 09, 2010 9:46 pm

Re: how to calibrate my bench with pts orifice plates

Post by larrycavan »

PM308 wrote: is there any need to check flow with the head stand, the way i see it is that it just adds another variable when trying to compare to other benches as not all bore diameters will be the same.

That's another matter entirely. Some would argue pro and others con. Mostly con.

Big Blue long ago established that when checking "functionality" [not calibration, mind you] on their benches, their "test" [not calibration] plate is bolted to the bench top with no stand used.

Since anything upstream of the cabinet holding the calibrated orifice could be a variable [size difference, etc], it could impact the "functionality" test. So, with that thought in mind, "most" people tune their ranges with no stand on top of the bench.

BTW... did you ever get the opportunity to test the 100CFM plate in the 100CFM range, against the 600 CFM range that goes as low as 40CFM?

I'd be VERY interested in those particular results. It's a personal issue that I'm trying to run down some data on. :)
Larry C

http://www.cavanaughracing.com
PM308
Posts: 5
Joined: Sat Jan 07, 2012 10:57 am

Re: how to calibrate my bench with pts orifice plates

Post by PM308 »

i havent checked the 100cfm plate on range 1 since the new correction factor but when i checked it the 1st time it was within a cfm or 2 i cant remember if it was higher or lower so it should ( i think ) be about 2% lower this time as my correction factor has gone from .994 to .972 after dialing it in on the 300 plate,

i will recheck and let you know
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