Window screen grille block?

[mcrews]

not really sure what the discussionm is REALLY all about.
Why do you feel forced to use steel screening????????

I got this stuff at the hardware store...... probably a plastic of some kind, was on a large role. I bought a section that would fit. THe holes are obviously smaller than ANY thing being discussed, which nigates the arguement of what to use out of the set of sizes your discussing.

[d0sitmatr]

Originally Posted by mcrews

not really sure what the discussionm is REALLY all about.

well, it was originally about using screening materials for a grill block, but has diversified into various other ideas

now THAT would make a good grill block !
I think, looking at it, it probably only lets through 10% ? (Im guessing, but Id say 10% would be an "at best")

[mcrews]

That's my point.
It's like have a discussion about the different width of tires....70, 60, 50 and how well they make a car handle. Only to find uot that their are 45 and even 35 available!!!!

It's a meaningless discussion when in the real world there are several products that will serve the purpose.

THis current grille block was used (with several other mods) to achieve 30.4mpg over 1700 miles at 59mph moving average over 2 days from 300ft elevation thru 7000+(Flagstaff) on to Abilene Texas. In a 3801lb, V8 4dr vehicle with an EPA of 22mpg hwy.

[jthistle]

The point of testing multiple meshes with different open hole areas is to find the one that passes the most air at low speeds and blocks the most air at high speeds. Testing with a air flow meter hopefully will give instantaneous results where as making grill blocks requires you to do coast down tests and run multiple tanks of fuel to track the changes. The discussion has always been about mesh grill blocks. It has gotten quite technical as we have tried theorize the effect of using mesh as a grille block by applying research that has been done by others on similar topics.

I got this stuff at the hardware store...... probably a plastic of some kind, was on a large role. I bought a section that would fit. THe holes are obviously smaller than ANY thing being discussed

As verified by d0sitmatr most screening material for window screens is ~70% open area. d0sitmatr tested window screening previously and saw no benefit. The smallest screening I purchased for my test has 29% open area with hole sizes of 0.023 inches.

I am not set on using stainless mesh for the final grill block but it is convenient for testing purposes. I can buy meshes with specific open areas. The stainless meshes are more rigid than plastic which will not require me to support the center of the test area to prevent wobble.

It would be helpful if you could find out what open hole area the screening you are using has and what effect your grill block alone has on your MPG by testing with and without it.

This is what the 29% open area mesh looks like

[mcrews]

actually, if you would read mods and posts by others, you would see that 'multilpe tanks of gas' have never been used.
1. you can't test in the real world using multiple tanks of gas. (something that seems obvious to the untrained mind.)
UNLESS your sitting in a controlled chamber for the multiple tanks.
2. everyone here uses a-b-a testing. there are plenty of posts converning how to do it but simply stated:
a defined distance-8-12 miles, that you run both ways to offset wind. a= n0 mod, b=mod. I usually run at midday. I always drive the car 15 minutes before the run. I set the cruise control for the entire run. I reset the scangauge at the same mile marker.
i ussully set the cruise at 55, 60 and/or 65. depending on how much time I want to spend
3. by have a controlled test run, I can chart results over months and yrs. I can see the effect of hot summer against cold winter.
4. bottom line, any mod I have every done never took more than 2 gallons to validate.
5. someone might say " you scangauge isnt accurate" "only filling the tank is". that statement misses the point of testing. It doesn't matter if the gauge is 'accurate'. it could be off 10,50, 100%. But it is going to ALWAYS BE OFF THE SAME AMOUNT!
I don't 'reset the internals'. I just set the trip back to 0.
But the fact is that due to the proper setup in the beginning, my scangauge is close enough to the actual consumption.

as for the cost of 'several tanks of gas', that would be $100- 200. i get 400 miles to a gallon. two tanks is 10 hours. How can you control ten hous of driving? and how do you control the test with and with uot? I bill my business time at $225 an hour. If i can get the material, install it and test it in 2 hours, then I'm done. The time spent reseaching and look for multiple sources may be fun but it is not financially effecent.
all of course is just one man's perspective....

ps. mike said "I think, looking at it, it probably only lets through 10% ? (Im guessing, but Id say 10% would be an "at best") "

and you are saying I'm at...........29%????

that is one problem with this tread. No pictures of the items being discussed. and when finally, a picture is introduced by a third party, the expert, Mike, says wow 10%. Yet this entire thread revolved around the larger 30% and suggesting that a better result was improbable.
Finally, the whole 'ramdom' discussion about the angle of the screen....to what point???? Are you going to redesign the entire front end to achieve the 'correct angle' for the screen to work???? that's know as 'waging the dog'.
Go buy a $5 piece of screen and aba.
just had an wild, off the wall, crazy thought........
go buy 3 pieces, test w/ one, the put 2 together, test, then put 3 together ...test.
and dont spend 5 hours looking for a scientific study of randomly laying 3 sheets together and all the holes lining up to create no improvement.

[jthistle]

You are correct about the a-b-a tests I was wrong. I was not trying to slam you. However you seem intent on dismissing my test by saying some random stuff you picked up at a hardware store had some positive effect on your vehicle so there is no point in doing anything else.

I want to know what the effects of different mesh sizes have on the air flow through the mesh and if that can translate to effective grill blocking. Maybe I will get meaningful results maybe not. But that is certainly no reason to just not do it. I am the kind of person who enjoys doing the research and quantifying the results as fully as I can. I intend on doing the test I have laid it out regardless if others think

It's a meaningless discussion when in the real world there are several products that will serve the purpose.

I would appreciate constructive criticism on such things as how to make the test better.

[mcrews]

you got em.

What you want to do as a scientist or researcher are personal choices that each of us make everyday.
some want to spend hours making their own beer.
I know a man who rewrote the entire bible in verse form.
we are all wired a little differently.
From my point of view, you are grabbing on to some very minor point and beating it to death when the end result will be measured in 10ths of a percent.
Your point of view is different.
My point is very constructive because I believe in helping to see thru to the bigger picture.
How you recieve that and process it and handle it is not my concern. Someone of like mind may respond and help you with your test, great.

[jthistle]

mcrews when you switched from the solid plastic grill block that is in the links in your sig to window screen how did it affect the MPG of your car.

[jthistle]

ps. mike said "I think, looking at it, it probably only lets through 10% ? (Im guessing, but Id say 10% would be an "at best") "

The smallest mesh available on McMaster's website is 18.4% open area. The holes are 0.0007 inches wide, it has 635 openings per inch and is sickly expensive (~$750/sq. ft.). It seems to be made for a very small particle sieve. Looking at the picture you provided with measurements of your stock grill your mesh seems to be 18 openings per inch which depending on the wire size would put it at 40 - 50% open area.

[d0sitmatr]

sorry, I was joking when I said 10%
I thought everyone would get it, I forget that many dont understand my sense of humor