[DeTomaso] determine if JFFR scoops are effective

[Joseph F. Byrd, Jr.]

Thanks Stephen...I thought I had made a file of your work, but forgotten what I named and where I saved it :(

The sealed pressure reference is a method, just requires rather large physical elements.  I would still lean towards a static port.

I now have a low pressure manometer and thinking about what would be the minimum testing (optimizing track time) that would prove the scoops effectiveness and possible some other useful aerodynamic data.

When I plan for equipment testing, I start with a simple mission statement and fill in till I develop my procedure

Thus to start

Install tubing to measure test points from within the cockpit
1)	Tap hole into the air box at the filter element
2)	Diffusing probe on top of the carb stud 
3)	Adjustable Pitot tube

The adjustable pitot is to find a “free stream” static reference.  The pitot dynamic (total-static) will be measure over the speed range to find the height that has the pitot outside of the boundary layer.  This is a position where the dynamic equal the calculated for each speed (or farther extension does not show increase dynamic.  Once set, this will the reference for the other two pressures

The air box pressure, The best case is the air box pressure will increase with speed with the offset being the air consumed by the engine.  If boundary layer at a given speed, the air box the pressure will no longer increase with speed.  Worse case the boundary creates turbulence that results in negative pressure

The carb stud with respect to the pitot will provide the negative pressure generated at the rear window. 

-----Original Message-----
From: Stephen Nelson [mailto:steve at snclocks.com] 
Sent: Wednesday, November 22, 2017 9:55 AM
To: 'Joseph F. Byrd, Jr.'; detomaso at server.detomasolist.com
Subject: RE: [DeTomaso] determine if JFFR scoops are effective

Good morning Joseph.  When I was doing my rear-window flow testing I used a pressure bomb as my "static" pressure.  I wrapped the bomb in towels, put it in a cooler, which I then put in the trunk.  At that point I could look at a relative pressure, always knowing that any changes as the car moved would be compared to the reading when the car was standing still.  And yes, I thought about using the pressure in the car as my reference, but I am pretty sure the inside of the car pressurizes as we go down the road.  Or, perhaps it depresses - don't know.

Stephen

-----Original Message-----
From: DeTomaso [mailto:detomaso-bounces at server.detomasolist.com] On Behalf Of Joseph F. Byrd, Jr.
Sent: Wednesday, November 22, 2017 5:01 AM
To: detomaso at server.detomasolist.com
Subject: [DeTomaso] determine if JFFR scoops are effective

>From the K Busch discussion, a side discussion was the JFFR scoops.  

What would be the measurements needed to determine if those scoops are effective.  

One of my thoughts would be to use a manometer (digital) insert the sensing side tubing into the scoop until it is at the air filter.  The location of the reference tubing then becomes a concern.  I have two thoughts.   
First is to reference the space where a normal air filter would be getting its air.  Given the pressure at the rear window, it would be a measurement of actual benefit,   
the second thought is to use a pitot in "clean air" and use the static port.  This would be more indicative of the benefit as if on a stationary dyno

ANY thoughts?

-----Original Message-----
From: DeTomaso [mailto:detomaso-bounces at server.detomasolist.com] On Behalf Of Joseph F. Byrd, Jr.
Sent: Monday, November 20, 2017 12:09 PM
To: detomaso at server.detomasolist.com
Subject: Re: [DeTomaso] Kurt Busch Pantera

Here are more ramblings of My troubled mind!

I took a simple Bernoulli conversion approach to get some concept of the magnitudes that are being dealt with by the side scoops, definitely not a true aerodynamics solution.


On Sun, Nov 19, 2017 at 6:49 PM, JFFR <pantera at vtc.net> wrote:

> The side scoops that I am using are 1.5 inches at the widest point and 
> are feeding four inch hoses into the sealed air box. My fuel injection 
> system can flow about 1100 cfm at full throttle. I don't know how to 
> do the calculations, but I am sure that the scoops will supply more 
> air than the engine can use. My engine is 388 cubic inches and and 
> produces full power at about 6300 rpm. The rev limiter is set at 6550 
> rpm and in first gear I need to up shift into second gear pretty 
> quickly to keep from hitting the rev limiter. I have only had the car 
> up to about 140 mph, but it has never run out of power and was still 
> pulling hard at that speed. Public roads can limit how fast you can push a car and safety is always my concern.
>
> I just talked to the owner of the Inde Motorsports Ranch in Willcox 
> Arizona today. If any members of the club want to come here, we can 
> use the track to test this air box set up on my car. The straight is
> 2200 feet long and I can usually get my Pantera up to 120 mph before 
> having to brake for a sweeping right hand turn. The track use is free 
> because I work there and it is certainly nice to be able to do this 
> without having to worry about breaking any laws or endangering the public!