NEED HELP. help me calculate exhaust Gas Volume.

[K4fxd]

My gut says engine exhaust is just too damn little in volume let alone volocity to do a dn thing.

The top fuel and funny car guys do use exhaust for downforce. Some started slanting the pipes to give some forward thrust, NHRA shut them down and now regulates the the angle of the pipes.

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[Flyhalf]

Thats a shit ton of air and unless you or AJ haven't looked at the flows and figured the velocity and from where additional is needed to address the turbulence youre just guessing. My gut says engine exhaust is just too damn little in volume let alone volocity to do a dn thing.

By work I didn't mean cite AJ findings in a wind tunnel. But rather instrument your terminal speed down a suitable straight. Are you 4mph faster than without? How about elapsed between timing beacons?

You basically need something like what f1 does with multiple splits around the track at strategic locations.

I had the small verus engineers. so I just install it. I'll test.
Creating Downforce with diffuser will create drag. BUT, because the extra down force I can reduce the angle of the wing to reduce the overall drag .again, I will test and report.

the volume behind my mustang (extending for 1 meter behind)
Is around 2600liter
base on very rough calculations ( i can show you in DM) The car produces 200liter per second. (~8% of above volume) ..and for what I found out the "vacuum" area behind the car is 10%less dense than the rest.. that is why I was thinking to use exhaust there.

 

[Flyhalf]

The top fuel and funny car guys do use exhaust for downforce. Some started slanting the pipes to give some forward thrust, NHRA shut them down and now regulates the the angle of the pipes.

in this case no DOWNFORCE but drag reduction . you can blow the diffuser ( like f1 does) to increase downforce but it works only on throttle and also you can have some issues in heat management if you blow hot air around the diffuser

 

[5doorsoffury]

What is the MAF G/S reading and is the maf calibrated ? i would just take the G/S and multiply it by the seconds at wot. that is the total air mass ejected then you work out velocity by sticking that volume in a pipe of a certain diameter then u get the velocity from that and ur good. I am sure there are multiple calculator sites ( in multiple languages) that can help. The maf literally tells you the grams of air ingested and the temp (not humidity)so you can calculate density.

 

[K4fxd]

The car produces 200liter per second.

Depends on RPM or did you average it

at 8000 rpm I get 333 liters per second

 

[K4fxd]

in this case no DOWNFORCE but drag reduction

I posted that to show how one form of motor sport uses exhaust.

As far as filling the air space behind the car, I would think if it worked the NASCAR boys from the 60's and 70's would have used it on the big tracks.

 

[Flyhalf]

What is the MAF G/S reading and is the maf calibrated ? i would just take the G/S and multiply it by the seconds at wot. that is the total air mass ejected then you work out velocity by sticking that volume in a pipe of a certain diameter then u get the velocity from that and ur good. I am sure there are multiple calculator sites ( in multiple languages) that can help. The maf literally tells you the grams of air ingested and the temp (not humidity)so you can calculate density.

that is actually a good point. Also there is the mass of the fuel to calculate and the oxygen on hit . there was a website i used in the past .I'll share the link when i find it

 

[Flyhalf]

Depends on RPM or did you average it

at 8000 rpm I get 333 liters per second

7000rpm.

 

[CrazyHippie]

(This post is 100% tongue-in-cheek for those of us who have studied this ......)

The formula is

PV=nRT

Where P=pressure, V=Volume, n is the number of moles of gas involved, R is a gas constant and T is temperature.

Easy peasy.

 

[Flyhalf]

Well. Car goes under surgery for a new transmission but I'll try to have it back for dec 16 to try it at buttonwillow .fingers crossed please.
I'll test max speeds
Cool to see in this video where the gasses are pointing : right where a big air vacuum is (or better less dense air area) ,just behind the car.

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