Someone please check my calcs. with this compressor map please! TIA
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Someone please check my calcs. with this compressor map please! TIA
http://www.blackphoenixtech.co...t.xls
there is all the calculations i made in excel (took FOREVER!)
and here is the turbo map for the turbo i am thining of getting.
I am confused of how to plot the points on the Comp Map, do i adjust the PR to the rpm to get a slope?
Please tell me if all my calculations are correct and if this turbo is suitable
need your turbo smart people to give me a hand before i spend my $$ on the wrong ****! Thanks a million!!!
Modified by shaun311 at 2:26 PM 1/22/2005
there is all the calculations i made in excel (took FOREVER!)
and here is the turbo map for the turbo i am thining of getting.
I am confused of how to plot the points on the Comp Map, do i adjust the PR to the rpm to get a slope?
Please tell me if all my calculations are correct and if this turbo is suitable
need your turbo smart people to give me a hand before i spend my $$ on the wrong ****! Thanks a million!!!
Modified by shaun311 at 2:26 PM 1/22/2005
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From: Northern, VA
Re: Someone please check my calcs. with this compressor map please! TIA (shaun311)
assuming 130 degree f intake manifold temp, 90% intake efficiency, and a 1.5 psi pressure drop from IC...
cubic ft/min = rpm X engine cid / 1728 X 2
volume of air = (8,000 rpm X (1,600cc/(16.39cid/cc)))/ ((1728 cid/cf)X2rpm)
~225.93 CFM * .90 = 203.4 CFM efficiency
absolute temp. -> 130 deg F + 460 = 590 deg R
absolute press. -> 20 psi + 14.7 psi = 34.7 psi
pressure in = 14.7 PSI - .5 PSI = 14.2 PSI
pressure out = 20 PSI + 14.7 PSI + 1.5 PSI = 36.2 PSI
pressure ratio = pressure out/pressure in
pressure ratio = 36.2 / 14.2 -> 2.55
everything sounds about right except, there is a vacuum present at the inlet of the turbo
cubic ft/min = rpm X engine cid / 1728 X 2
volume of air = (8,000 rpm X (1,600cc/(16.39cid/cc)))/ ((1728 cid/cf)X2rpm)
~225.93 CFM * .90 = 203.4 CFM efficiency
absolute temp. -> 130 deg F + 460 = 590 deg R
absolute press. -> 20 psi + 14.7 psi = 34.7 psi
pressure in = 14.7 PSI - .5 PSI = 14.2 PSI
pressure out = 20 PSI + 14.7 PSI + 1.5 PSI = 36.2 PSI
pressure ratio = pressure out/pressure in
pressure ratio = 36.2 / 14.2 -> 2.55
everything sounds about right except, there is a vacuum present at the inlet of the turbo
Thread Starter
Honda-Tech Member
Joined: Mar 2003
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From: Right Near The Beach, NJ, USA
Re: Someone please check my calcs. with this compressor map please! TIA (TurboSmart)
ok thank you very much for all the time you put into writing that!
i just have a couple more questions.
so they new numbers i will be using on the chart are
pressure ratio = 36.2 / 14.2 -> 2.55
and
pressure out = 20 PSI + 14.7 PSI + 1.5 PSI = 36.2 PSI?
also, when i tried plotting my point of the map after the first point (8000) they would just start going right off the map over the surge limit i think the problem is that i am not adjusting the PR as the rpms decrease is this correct? if so how do i adjust them accordingly?
i just have a couple more questions.
so they new numbers i will be using on the chart are
pressure ratio = 36.2 / 14.2 -> 2.55
and
pressure out = 20 PSI + 14.7 PSI + 1.5 PSI = 36.2 PSI?
also, when i tried plotting my point of the map after the first point (8000) they would just start going right off the map over the surge limit i think the problem is that i am not adjusting the PR as the rpms decrease is this correct? if so how do i adjust them accordingly?
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From: Now in SoCal, CA, USA
Re: Someone please check my calcs. with this compressor map please! TIA (shaun311)
I'll give you a bump... it's good to see someone doing thier homework rather then just buying the bandwagon turbo.
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From: Baltimore, MD, US
Re: Someone please check my calcs. with this compressor map please! TIA (turbosi03)
this might help you out, or give you a little more info. I never fully figured it out. I mapped all the conditions on the map of my turbo but dont really know what it did for me or where i stand.
https://honda-tech.com/zerothread?id=1075401
https://honda-tech.com/zerothread?id=1075401
Thread Starter
Honda-Tech Member
Joined: Mar 2003
Posts: 2,359
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From: Right Near The Beach, NJ, USA
Re: Someone please check my calcs. with this compressor map please! TIA (adictionbass)
me too im kinda disappointed in ht hah, its confusing **** though... well to me
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