VE calculator??? Stu? Simon?
20-05-2005, 11:52 AM
#1
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VE calculator??? Stu? Simon?
Todays maths challenge!
Does any one know the the calculation to work out engine volumetric efficiency using:
Capacity
Power/torque
Engine speed
And i think you might need AFR at max power?
Is there an online calculator?
Trying to work out air flow through an engine for turbo compressor housing and wheel selection but all the calculations seem to use guessed VE values.
Cheers,
Doug.
Does any one know the the calculation to work out engine volumetric efficiency using:
Capacity
Power/torque
Engine speed
And i think you might need AFR at max power?
Is there an online calculator?
Trying to work out air flow through an engine for turbo compressor housing and wheel selection but all the calculations seem to use guessed VE values.
Cheers,
Doug.
20-05-2005, 12:00 PM
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Just stick a fooook off big one on there mate, loads of lag!!! 
Think Cooups started sorting my engine at last, he gave me my head back the other day, his mate has welded all the stud holes and built up the edges so the new inlet manifold fits, proper work of art!!
How you getting on?
Think Cooups started sorting my engine at last, he gave me my head back the other day, his mate has welded all the stud holes and built up the edges so the new inlet manifold fits, proper work of art!!
How you getting on?
20-05-2005, 12:53 PM
#4
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Originally Posted by Rossco
Just stick a fooook off big one on there mate, loads of lag!!!
Think Cooups started sorting my engine at last, he gave me my head back the other day, his mate has welded all the stud holes and built up the edges so the new inlet manifold fits, proper work of art!!
How you getting on?
Think Cooups started sorting my engine at last, he gave me my head back the other day, his mate has welded all the stud holes and built up the edges so the new inlet manifold fits, proper work of art!!
How you getting on?
An artist with a TIG torch!
20-05-2005, 03:37 PM
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VE can be roughly calculated but the only way is to actually measure it when the engine is running !
This is effectively why live mapping will always be needed !
The trouble is an engine Volumetric efficiency is it changes over rpm and throttle position.
I.E it is not a linear equation.
Gets even worse when you turbo charge an engine and it heats up the air
This is effectively why live mapping will always be needed !
The trouble is an engine Volumetric efficiency is it changes over rpm and throttle position.
I.E it is not a linear equation.
Gets even worse when you turbo charge an engine and it heats up the air
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20-05-2005, 04:58 PM
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Originally Posted by RS2300 4x4
http://www.megasquirt.info/manual/vetable.htm
Mark
Mark
20-05-2005, 05:35 PM
#10
Professional Waffler
Originally Posted by SECS
Originally Posted by RS2300 4x4
http://www.megasquirt.info/manual/vetable.htm
Mark
Mark
20-05-2005, 06:57 PM
#13
Originally Posted by SECS
Originally Posted by RS2300 4x4
http://www.megasquirt.info/manual/vetable.htm
Mark
Mark
Only the fact that it will not work for my bike engine
How to I arrive at a rough VE table from this? (bearing in mind this was on some BADLY behaving carbs and I need a VE table to get me started in Megasquirt)
Running around 12 psi
Many thanks for any help
Mark
20-05-2005, 07:03 PM
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RS2300 4x4, the problem is, you need to know the peak torque at a given RPM in order for it to work.
Ok if the engine is known and power tested first.
But in order to power test an engine,you need to run it.
You cant run it without a fuel map from the VE table.
Chicken and egg syndrome.
Still, wasnt dissing it, as it can provide a good "guestimate" table
Ok if the engine is known and power tested first.
But in order to power test an engine,you need to run it.
You cant run it without a fuel map from the VE table.
Chicken and egg syndrome.
Still, wasnt dissing it, as it can provide a good "guestimate" table
21-05-2005, 06:28 AM
#17
Figs on dyno above are at the wheel and allowing around 10% transmission loss I get 168bhp and 110lbsft at 8000 rpm at 12 psi boost(approx) can anyone show me how to work the VE out for this single figure so I can apply it to the whole rev range?
PS this is what I get with the VE calculator
Is there somthing wrong with my dyno printout
Mark
PS this is what I get with the VE calculator
Is there somthing wrong with my dyno printout
Mark
21-05-2005, 08:46 AM
#18
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Mark,
Try using the VE table calculator thatis built Megatune. It is under tools on the ve table page.
I inputed your data as:
Idle 1000@40kpa
Torque 100@8000rpm@183kpa
Power 190@10750rpm@180kpa
Redline 11000rpm@175kpa
It gave me a table no probs.
Can e-mail it to yo if you like?
I have used total traction at Colchester before too.
Next time you take the bike up there to get some fueling sorted with the megasquirt give me a shout and I'll come and have a ganders/see if i can be of help.
Doug.
Try using the VE table calculator thatis built Megatune. It is under tools on the ve table page.
I inputed your data as:
Idle 1000@40kpa
Torque 100@8000rpm@183kpa
Power 190@10750rpm@180kpa
Redline 11000rpm@175kpa
It gave me a table no probs.
Can e-mail it to yo if you like?
I have used total traction at Colchester before too.
Next time you take the bike up there to get some fueling sorted with the megasquirt give me a shout and I'll come and have a ganders/see if i can be of help.
Doug.
21-05-2005, 09:17 AM
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It's not really too critical what kind of initial map you start with as long as it starts and runs. Then it's easy to tune from there with e.g. a WB-lambda.
21-05-2005, 02:50 PM
#20
Originally Posted by Garage19
Mark,
Try using the VE table calculator thatis built Megatune. It is under tools on the ve table page.
I inputed your data as:
Idle 1000@40kpa
Torque 100@8000rpm@183kpa
Power 190@10750rpm@180kpa
Redline 11000rpm@175kpa
It gave me a table no probs.
Can e-mail it to yo if you like?
I have used total traction at Colchester before too.
Next time you take the bike up there to get some fueling sorted with the megasquirt give me a shout and I'll come and have a ganders/see if i can be of help.
Doug.
Try using the VE table calculator thatis built Megatune. It is under tools on the ve table page.
I inputed your data as:
Idle 1000@40kpa
Torque 100@8000rpm@183kpa
Power 190@10750rpm@180kpa
Redline 11000rpm@175kpa
It gave me a table no probs.
Can e-mail it to yo if you like?
I have used total traction at Colchester before too.
Next time you take the bike up there to get some fueling sorted with the megasquirt give me a shout and I'll come and have a ganders/see if i can be of help.
Doug.
Can you email me the .vex file please mate, will PM you my email address. With regards to total traction you are more than welcome to come and help if you can spare the time
Mark
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