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Thoughts on an engine simulation

Thoughts on an engine simulation

Thoughts on an engine simulation

(OP)
Ok, I've got this program called Desktop Dyno 2000. Anyway, i'm sure its not the most accurate thing in the world, but its fun to play with and its pretty cheap, so why not.

Now, I put in the stats for a stock 4.9L ford and it was pretty close (http://bigblocksix.com/stock.png). A typical buildup is here http://bigblocksix.com/typical_buildup.png and my new super-great N/A buildup is here: http://bigblocksix.com/lots_of_work.png

I'm looking at that last pic and i'm seeing two HP peaks. Why would that be?


-=Whittey=-

P.S. That is a simulation of a 4.9l with the alan johnson head and a schneider off-the-shelf cam.

RE: Thoughts on an engine simulation

the 2 HP peaks are probably the result of
"calculated" torque curve thats too wide or
not falling off enough

a torque curve thats not varying enough
to simulate real conditions .

your torque should be more like this or some where between
half way between this and Desk Top Dyno

RPM=3000   Torque=218.5    HP=124.8
RPM=3100   Torque=223.6    HP=132.0
RPM=3200   Torque=228.7    HP=139.4
RPM=3300   Torque=234.0    HP=147.0
RPM=3400   Torque=239.3    HP=154.9
RPM=3500   Torque=244.7    HP=163.1
RPM=3600   Torque=250.3    HP=171.6
RPM=3700   Torque=255.9    HP=180.3
RPM=3800   Torque=261.6    HP=189.3
RPM=3900   Torque=267.4    HP=198.6
RPM=4000   Torque=273.3    HP=208.2
RPM=4100   Torque=279.3    HP=218.0
RPM=4200   Torque=285.3    HP=228.1
RPM=4300   Torque=291.3    HP=238.5
RPM=4400   Torque=297.4    HP=249.2
RPM=4500   Torque=303.6    HP=260.1
RPM=4600   Torque=309.7    HP=271.3
RPM=4700   Torque=315.8    HP=282.6
RPM=4800   Torque=322.0    HP=294.3
RPM=4900   Torque=328.1    HP=306.1
RPM=5000   Torque=334.2    HP=318.1
RPM=5100   Torque=340.2    HP=330.3
RPM=5200   Torque=346.1    HP=342.6
RPM=5300   Torque=351.9    HP=355.1
RPM=5400   Torque=357.6    HP=367.7
RPM=5500   Torque=363.1    HP=380.3
RPM=5600   Torque=368.5    HP=392.9
RPM=5700   Torque=373.7    HP=405.6
RPM=5800   Torque=378.7    HP=418.2
RPM=5900   Torque=383.4    HP=430.8
RPM=6000   Torque=387.9    HP=443.2
RPM=6100   Torque=392.1    HP=455.5
RPM=6200   Torque=396.1    HP=467.5
RPM=6300   Torque=399.6    HP=479.4
RPM=6400   Torque=402.9    HP=491.0
RPM=6500   Torque=405.8    HP=502.2
RPM=6600   Torque=408.3    HP=513.1
RPM=6700   Torque=410.4    HP=523.5
RPM=6800   Torque=412.1    HP=533.6
RPM=6900   Torque=413.4    HP=543.1
RPM=7000   Torque=414.3    HP=552.1
RPM=7100   Torque=414.7    HP=560.6
RPM=7200   Torque=414.7    HP=568.5
RPM=7300   Torque=414.3    HP=575.9
RPM=7400   Torque=413.4    HP=582.5
RPM=7500   Torque=412.2    HP=588.6
RPM=7600   Torque=410.5    HP=594.0
RPM=7700   Torque=408.4    HP=598.7
RPM=7800   Torque=405.9    HP=602.8
RPM=7900   Torque=403.0    HP=606.2
RPM=8000   Torque=399.8    HP=609.0
RPM=8100   Torque=396.2    HP=611.1
RPM=8200   Torque=392.3    HP=612.6
RPM=8300   Torque=388.1    HP=613.4
RPM=8400   Torque=383.7    HP=613.6
RPM=8500   Torque=379.4    HP=614.0
RPM=8600   Torque=374.0    HP=612.3
RPM=8700   Torque=368.8    HP=610.9
RPM=8800   Torque=363.4    HP=608.9
RPM=8900   Torque=357.9    HP=606.4
RPM=9000   Torque=352.2    HP=603.5
RPM=9100   Torque=346.4    HP=600.1
RPM=9200   Torque=340.4    HP=596.4
RPM=9300   Torque=334.4    HP=592.2
RPM=9400   Torque=328.4    HP=587.7
RPM=9500   Torque=322.3    HP=582.9

414.7 Torque @ 600 RPM/SEC accel dyno rate should be
equal to 14.00:1 CR

the 470 peak Torque for 14:1 CR is pretty high
even at steady state dyno test

5500 RPM=470 TQ




Larry Meaux (meauxracing@mindspring.com)
Meaux Racing Heads - MaxRace Software
ET_Analyst for DragRacers
http://www.mindspring.com/~meauxracing/
     Support Israel - Genesis 12:3

RE: Thoughts on an engine simulation

(OP)
Would there ever be a case where a motor would have two hp peaks like that? What about torque peaks?


-=Whittey=-

RE: Thoughts on an engine simulation

yes...you can have 2 Torque or HP peaks

mostly occurs because of Intake and Exhaust systems not in phased or in other words, not tuned together for one curve

most of times, it will be the exhaust side responsible
for the higher RPM 2nd Torque or HP peak

but looking at the DeskTop dyno picture , the Torque is too high for CID and CR , and this could cause 2 HP peaks also.

Larry Meaux (meauxracing@mindspring.com)
Meaux Racing Heads - MaxRace Software
ET_Analyst for DragRacers
http://www.mindspring.com/~meauxracing/
     Support Israel - Genesis 12:3

RE: Thoughts on an engine simulation

You can get even more than two peaks.  This is due to the tuning of the intake system.  pressure waves reflect off of the various transisions and plenums in the intake system (intake manifold, resonators, air cleaner box, etc.)

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