That's a good idea. Where can I find that info?

Why do these sites claim 300% VE for turbocharged engines?

EDIT: So if you wanted to figure it with 60% VE just take 3/4 of the numbers I posted.

 

i came up with 570 CFM @ 3200 RPM for a truck running 20 PSI @ 550 ft altitude @ 90* w/ 75% compressor efficiency, 2 PSI pressure drop across the IC, 70% IC efficiency, and 65% VE.. sounds close to me..

 

No reason for any of us to use the 6637 if the stock truck can pull air faster than it can flow CFM.

The only reason I'm saying something doesn't seem right, is because if our upgraded filter cannot support it, the stock filter doesn't' stand a snowballs chance in hell to flow enough air.

You have to figure the flow into the heads in there someplace, our OBS's have a huge restriction there.

There has to be something missing.
Not sure what.

Ask Cuda Jim. haha.

 

There IS lots of info missing such as compressor efficiency, IC efficiency, and actual VE.. these are assumptions and can't be taken to heart, but something to think about for sure.

I came up with 697 CFM by moving up to 30psi and dropping compressor efficiency to 65%. i dropped compressor efficiency b/c that would be moving out of our compressor map

think about this... you have an aftermarket turbo that is supposed to flow 1200 CFM, how can you expect a single 6637 to do that job?

 

I recalculated the 20 psi @ 60% VE to see if I got the same as you and I did. Does that mean I just used to high of a VE?
Did you use some sort of online calculator or chart or did you hand calculate it the way I did? Just curious on your method.
At this point I'm more concerned on how to actually calculate it. Like I said, the only thing I looked up was VE, b4 this morning I had never heard of it.

Talyn, the VE accounts for air flowing through the heads.

Couldn't find the cfm rating of our stock turbo, but the SD turbo is rated for 897 cfm.
So if ours in anywhere close to that, what do you think the actual cfm is for various boost levels?

 

so it flows 897 CFM so now if i'm thinking right you need the compressor efficiency to find the CFM that the charger will be pulling into it. i saw a formula for that somewhere, i just don't remember where. CFM output of the charger isn't the same as the CFM that it's pulling in since it's compressing the air so much right??? i'm learning just like everyone here, but i can do math.

so maybe what we found earlier is correct for inlet CFM?????

 

Yes, that's what I was trying to find.

cfm varies based on pressures. All I know is the the same number of atoms that enters a compressor, leaves a compressor. So that means the the output cfm is much less than the input cfm. See now we are getting back to P*V = n*R*T. If I knew the number of atoms the engine was taking in I could calculate the volume of air at atmospheric conditions that would have to go through the filter.

This all started because I had read the flow rate of the 6637 in the CR cummins thread going on right now, and I was curious if was too big or too small or just right. All I had ever heard was just that is was better than stock.

 

Read this fellers--> https://www.ford-trucks.com/forums/6...ml#post5267145

and this too------> https://www.ford-trucks.com/forums/6...tion-data.html

 

After reading those it seems that some of my error was in the air temperature. I had no idea what to use so I just decided 70 F was good enough. I guess that was way too low.
That change would put me pretty darn close to what his charts show. I guess if I would've taken the time to at least look closer at what values I to use, we could've saved some of this. But, it did make for good reading.

I wonder how threads like that just drop off. It doesn't really have an ending, you know.

 

I'm impressed guys .. math skills and thought processes are alive, keep thinking different and the ideas coming and you will never fail in life.

 

Very well said Jim, I think these guys missed there calling in life. I told Travis that once but he wouldn't listen. Phil, you must milk by hand and have to much time to think!

 

I enjoy my thinking a lot more this way!! I appreciate the kind comments. the milkman started it though..

 

We have "semi-automatic" milker's at the dairy. While working we talk about mostly about trucks and farming. It helps when you work with someone in your own intelligence range so you can actually have discussions like this. When I work with other people, like the high schoolers, all they want to talk about it blowing smoke or who almost got in a fight at school. That fine, but after 6-8 hours of that, it gets old.

I don't think I've missed my calling though guys. I'm going into Junior year at IPFW where I'm studying Mechanical Engineering. Eventually I want to start my own business building performance truck parts and agriculture equipment.
Thanks for the support.

 

dang smart kids......... LOL

 

It looks like maybe a NAPA 6280 will work for me.
This site has Filters for cheap!
Here's a link to the 6637 for $26: Your Auto Supply - Fleet Filters - Wix Filters - Discount Auto Parts