What did YOU do tonight? pictures included.
01-03-2006, 07:40 AM
#77
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Re: (AzCivic1.6)
yeah i found the turbo map
here is a little info.
lets say your bored your built motor to a masive 2250cc and reved it to 8k thats a 137 cubic inch motor.
(137/1728)*(8000/2)= 317 cfm at 100% volumetric effecency. since no motor runs at 100% we will multiply that my .85 for 85% even though most say 80% is the right number.
but 317*.85 = 270.157 cfm
270.157/14.472 = 18.66 lbs/min
so your car is going to flow 18.66 lbs/min, now look at the compressor map and picture where the number 18.5 and 19 lbs/min would be and follow it up per presure ratio , if you have the 94mm housing you will hit the surge line even before you get above presure ratios of 2. if you have the 104mm housing your going to be in surge the whole time. ideally one wants to be in the main effecency island which is around the 50 lb/min flow area a bit past a 4 cylinders potential
this is what i ment about a poor turbo , and anthony said it too.
edit: also note this is for the .60a/r which means that with your larger 1.01 a/r your even worse off.
edit #2: go here to look at other compresor maps, http://not2fast.wryday.com/turbo/maps/
also i didn't know your true motor specs and desired redline so i guessed.
edit #3: I also forgot that with increased presure ratio inlet temperature vs. outlet temp changes which also changes the flow of lbs/min, but even at presure ratios equating to 30 psi i did the calculations and you still end up riding the surge line the whole way up
Modified by prelittlelude at 1:03 PM 1/3/2006
here is a little info.
lets say your bored your built motor to a masive 2250cc and reved it to 8k thats a 137 cubic inch motor.
(137/1728)*(8000/2)= 317 cfm at 100% volumetric effecency. since no motor runs at 100% we will multiply that my .85 for 85% even though most say 80% is the right number.
but 317*.85 = 270.157 cfm
270.157/14.472 = 18.66 lbs/min
so your car is going to flow 18.66 lbs/min, now look at the compressor map and picture where the number 18.5 and 19 lbs/min would be and follow it up per presure ratio , if you have the 94mm housing you will hit the surge line even before you get above presure ratios of 2. if you have the 104mm housing your going to be in surge the whole time. ideally one wants to be in the main effecency island which is around the 50 lb/min flow area a bit past a 4 cylinders potential
this is what i ment about a poor turbo , and anthony said it too.
edit: also note this is for the .60a/r which means that with your larger 1.01 a/r your even worse off.
edit #2: go here to look at other compresor maps, http://not2fast.wryday.com/turbo/maps/
also i didn't know your true motor specs and desired redline so i guessed.
edit #3: I also forgot that with increased presure ratio inlet temperature vs. outlet temp changes which also changes the flow of lbs/min, but even at presure ratios equating to 30 psi i did the calculations and you still end up riding the surge line the whole way up
Modified by prelittlelude at 1:03 PM 1/3/2006
05-03-2006, 01:08 PM
#78
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Re: (prelittlelude)
https://honda-tech.com/zerothread?id=1449211
you forget that increases in pressure mean an increase in air flow. it doesn't just disappear.
"Based on my calculations a stock H22 flows 21 lb/min at 7000 RPM's. So at 10 psi that should be 34 lb/min and 20 psi thats 49 lb/min, at 30 psi you're looking at 64 lb/min of airflow (all theoretical, and all at 7000 RPM)."
that thread also has a link to a very nice spreadsheet.
anyway, here's the downpipe and a couple of other pics. the project was on hold for a while. full aeromotive eliminator setup.
you forget that increases in pressure mean an increase in air flow. it doesn't just disappear.
"Based on my calculations a stock H22 flows 21 lb/min at 7000 RPM's. So at 10 psi that should be 34 lb/min and 20 psi thats 49 lb/min, at 30 psi you're looking at 64 lb/min of airflow (all theoretical, and all at 7000 RPM)."
that thread also has a link to a very nice spreadsheet.
anyway, here's the downpipe and a couple of other pics. the project was on hold for a while. full aeromotive eliminator setup.
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