Turbo Efficiency Range for RX-8
#1
Administrator
Thread Starter
Turbo Efficiency Range for RX-8
Ok this thread was prompted by T-Rex-8's comment i have quoted below
All the RX8 community needs is nice 5x trim sized, externally gated (for the serious) or internally gated (for the wussy) setup made for quick spool to deal with the RX8s low end power issues and getting the turbo further into its sweet spot. No more of these oversized turbos the RX8 can barely spool, do these vendors realize how far out of the efficiency range all of these turbos are being ran?
Id like to see posted here the compressor maps for the various Turbos in the available turbo kits out there so we can have a discussion on which T is really the best suited for the 8 . Also Id like to see T_Rex post up what he thinks is the correctly sized Turbo.
Lets compare. I don't have time right now to collect them myself from the various threads as im due in the living room for a butt whooping at GO FISH
All the RX8 community needs is nice 5x trim sized, externally gated (for the serious) or internally gated (for the wussy) setup made for quick spool to deal with the RX8s low end power issues and getting the turbo further into its sweet spot. No more of these oversized turbos the RX8 can barely spool, do these vendors realize how far out of the efficiency range all of these turbos are being ran?
Lets compare. I don't have time right now to collect them myself from the various threads as im due in the living room for a butt whooping at GO FISH
#2
Illudium Q-36 Space Moderator
iTrader: (1)
Where is that pic of the three turbo's Jeff made?
I can never find it when I want it.
This seems kinda stupid unless we all ahve an equal Mass Airflow we are going for.
So to start off - I say the RX8 range should be - 7 lb/min to 55 lb/min would be our operating range... seem fair?
I can never find it when I want it.
This seems kinda stupid unless we all ahve an equal Mass Airflow we are going for.
So to start off - I say the RX8 range should be - 7 lb/min to 55 lb/min would be our operating range... seem fair?
Last edited by Kane; 01-16-2009 at 11:19 PM.
#6
Administrator
Thread Starter
good read which is on topic
http://www.rbracing-rsr.com/turbotech.html
edit: another helpful link
http://www.automotivearticles.com/Turbo_Selection.shtml
http://www.rbracing-rsr.com/turbotech.html
edit: another helpful link
http://www.automotivearticles.com/Turbo_Selection.shtml
#10
Illudium Q-36 Space Moderator
iTrader: (1)
PR Compressor = (boost - PD + ambient)/ambient
Ideal Temp Out =[(Tin + 460) * PR^.283]-460
Actual Temp Out = [(Tout Ideal – Tin) / Efficiency] – Tin
Density Ratio = PR * [(Tin + 460)/(Tout+460)]
Engine Displacement +[(#Cyl)*(Stroke)*(Bore)^2]/1.27
VFR100% = [(Disp)(RPM)]/ 3456 or 1728 rotary
VFRactual = (VFR100%)(VE)
MFR - NA = [(2.703)(PAmbient)(VFR)]/[TAmbient + 460]
MFR - FI = (MFR-NA)(DR)
Ideal Temp Out =[(Tin + 460) * PR^.283]-460
Actual Temp Out = [(Tout Ideal – Tin) / Efficiency] – Tin
Density Ratio = PR * [(Tin + 460)/(Tout+460)]
Engine Displacement +[(#Cyl)*(Stroke)*(Bore)^2]/1.27
VFR100% = [(Disp)(RPM)]/ 3456 or 1728 rotary
VFRactual = (VFR100%)(VE)
MFR - NA = [(2.703)(PAmbient)(VFR)]/[TAmbient + 460]
MFR - FI = (MFR-NA)(DR)
#11
Everything you're asking for has already been answered....
The best turbo for the RX8 would have a custom turbine housing and we already know which turbo has that.
Huh? There's two sides to a turbo and you're forgetting the other side.
The best turbo for the RX8 would have a custom turbine housing and we already know which turbo has that.
Huh? There's two sides to a turbo and you're forgetting the other side.
Last edited by Flashwing; 01-16-2009 at 10:30 PM.
#12
Illudium Q-36 Space Moderator
iTrader: (1)
For the 50 lb/min goal.
VFR100% = [(Disp - 80ci)(9000)]/1728 rotary = 417 CFM
MFR - NA = [(2.703)(14.7PSI)(VFR - 417)]/[TAmbient-80 F] + 460] = 30.6 lb min
MFR - FI = (30.6 lb min) * Density Ratio of 1.68 = 51.4 lb/min
PR Compressor = (Boost (Say 16 lbs) - (Pressure Drop-2 PSI) + ambient)/ambient = 1.95
Ideal Temp Out =[(Tin of 80F + 460) * PR^.283]-460 = 192 F
Actual Temp Out = [(Tout Ideal - Tin) / Efficiency (Assume 70F)] + Tin = 240F
Intercooler Efficiency of 70% = 168 F
Density Ratio = PR * [(Tin + 460)/(Tout+460)] = 1.68
VFR100% = [(Disp - 80ci)(9000)]/1728 rotary = 417 CFM
MFR - NA = [(2.703)(14.7PSI)(VFR - 417)]/[TAmbient-80 F] + 460] = 30.6 lb min
MFR - FI = (30.6 lb min) * Density Ratio of 1.68 = 51.4 lb/min
PR Compressor = (Boost (Say 16 lbs) - (Pressure Drop-2 PSI) + ambient)/ambient = 1.95
Ideal Temp Out =[(Tin of 80F + 460) * PR^.283]-460 = 192 F
Actual Temp Out = [(Tout Ideal - Tin) / Efficiency (Assume 70F)] + Tin = 240F
Intercooler Efficiency of 70% = 168 F
Density Ratio = PR * [(Tin + 460)/(Tout+460)] = 1.68
#13
Illudium Q-36 Space Moderator
iTrader: (1)
So mark a 1.95 PR and 51 lb/min of air on the chart.
Now someone else do the 10 lb/min one.
Actually the PR would have to be higher since the VE isn't one.... but whatever. We could just round them to PR of 2 and 50 lb/min... this whole argument can get crazy otherwise.
Now someone else do the 10 lb/min one.
Actually the PR would have to be higher since the VE isn't one.... but whatever. We could just round them to PR of 2 and 50 lb/min... this whole argument can get crazy otherwise.
Last edited by Kane; 01-16-2009 at 10:34 PM.
#16
Illudium Q-36 Space Moderator
iTrader: (1)
Ahh **** it.
For the 7 lb/min goal.
VFR100% = [(Disp - 80ci)(1500)]/1728 rotary = 69.4 CFM
MFR - NA = [(2.703)(14.7PSI)(VFR of 69.4)]/[TAmbient-80 F] + 460] =5.1 lb min
MFR - FI = (5.1 lb min) * Density Ratio of 1.34 = 6.8 lb/min
PR Compressor = (Boost (Say 7 lbs) - (Pressure Drop-1 PSI) + ambient)/ambient = 1.41
Ideal Temp Out =[(Tin of 80F + 460) * PR^.283]-460 = 135 F
Actual Temp Out = [(Tout Ideal - Tin) / Efficiency (Assume 70%)] + Tin = 158F
Intercooler Efficiency of 70% = 110 F
Density Ratio = PR * [(Tin + 460)/(Tout+460)] = 1.34
For the 7 lb/min goal.
VFR100% = [(Disp - 80ci)(1500)]/1728 rotary = 69.4 CFM
MFR - NA = [(2.703)(14.7PSI)(VFR of 69.4)]/[TAmbient-80 F] + 460] =5.1 lb min
MFR - FI = (5.1 lb min) * Density Ratio of 1.34 = 6.8 lb/min
PR Compressor = (Boost (Say 7 lbs) - (Pressure Drop-1 PSI) + ambient)/ambient = 1.41
Ideal Temp Out =[(Tin of 80F + 460) * PR^.283]-460 = 135 F
Actual Temp Out = [(Tout Ideal - Tin) / Efficiency (Assume 70%)] + Tin = 158F
Intercooler Efficiency of 70% = 110 F
Density Ratio = PR * [(Tin + 460)/(Tout+460)] = 1.34
#17
Illudium Q-36 Space Moderator
iTrader: (1)
So we want a turbo that will boost to 7 PSI at 1500 RPM's and Hold 16 PSI at Redline Efficiently.
So
7 lb/min @ 1500 = PR of 1.5
50 lb/min @ 9000 = PR of 2
Now go find this magical turbo that will be efficient in this range......
Or more realistically - go find the one that is the best fit.
So
7 lb/min @ 1500 = PR of 1.5
50 lb/min @ 9000 = PR of 2
Now go find this magical turbo that will be efficient in this range......
Or more realistically - go find the one that is the best fit.
#18
Boosted Kiwi
iTrader: (2)
So we want a turbo that will boost to 7 PSI at 1500 RPM's and Hold 16 PSI at Redline Efficiently.
So
7 lb/min @ 1500 = PR of 1.5
50 lb/min @ 9000 = PR of 2
Now go find this magical turbo that will be efficient in this range......
Or more realistically - go find the one that is the best fit.
So
7 lb/min @ 1500 = PR of 1.5
50 lb/min @ 9000 = PR of 2
Now go find this magical turbo that will be efficient in this range......
Or more realistically - go find the one that is the best fit.
#19
Administrator
Thread Starter
So we want a turbo that will boost to 7 PSI at 1500 RPM's and Hold 16 PSI at Redline Efficiently.
So
7 lb/min @ 1500 = PR of 1.5
50 lb/min @ 9000 = PR of 2
Now go find this magical turbo that will be efficient in this range......
Or more realistically - go find the one that is the best fit.
So
7 lb/min @ 1500 = PR of 1.5
50 lb/min @ 9000 = PR of 2
Now go find this magical turbo that will be efficient in this range......
Or more realistically - go find the one that is the best fit.
#21
Administrator
Thread Starter
well until we get a couple more maps nothing except that i got you to do the math by leaving and getting my *** kicked at candy land by a 4 year old. totally worth it.
im goin to watch BSG now so if there is more to do.....
im goin to watch BSG now so if there is more to do.....
#24
Zoom-Freakin'-Zoom
iTrader: (5)
For the 50 lb/min goal.
VFR100% = [(Disp - 80ci)(9000)]/1728 rotary = 417 CFM
MFR - NA = [(2.703)(14.7PSI)(VFR - 417)]/[TAmbient-80 F] + 460] = 30.6 lb min
MFR - FI = (30.6 lb min) * Density Ratio of 1.68 = 51.4 lb/min
PR Compressor = (Boost (Say 16 lbs) - (Pressure Drop-2 PSI) + ambient)/ambient = 1.95
Ideal Temp Out =[(Tin of 80F + 460) * PR^.283]-460 = 192 F
Actual Temp Out = [(Tout Ideal - Tin) / Efficiency (Assume 70F)] + Tin = 240F
Intercooler Efficiency of 70% = 168 F
Density Ratio = PR * [(Tin + 460)/(Tout+460)] = 1.68
VFR100% = [(Disp - 80ci)(9000)]/1728 rotary = 417 CFM
MFR - NA = [(2.703)(14.7PSI)(VFR - 417)]/[TAmbient-80 F] + 460] = 30.6 lb min
MFR - FI = (30.6 lb min) * Density Ratio of 1.68 = 51.4 lb/min
PR Compressor = (Boost (Say 16 lbs) - (Pressure Drop-2 PSI) + ambient)/ambient = 1.95
Ideal Temp Out =[(Tin of 80F + 460) * PR^.283]-460 = 192 F
Actual Temp Out = [(Tout Ideal - Tin) / Efficiency (Assume 70F)] + Tin = 240F
Intercooler Efficiency of 70% = 168 F
Density Ratio = PR * [(Tin + 460)/(Tout+460)] = 1.68
beers
#25
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well first i think 55lb/min is a bit of a stretch for the typical street car. Thats around 490 at the flywheel
I think 40-45lb/min is a bit more realistic. 44lb/min is closer to 400 at the fly
^^this assumes AFRs of 11.2-11.5
that puts the 3071R at an almost perfect match. I dont think you'll find a turbo that will spool like everyone wants and still play nice at 55lb/min.
i couldnt find the Esmeril compressor chart, if it was ever posted - i think it's gone now.
I think 40-45lb/min is a bit more realistic. 44lb/min is closer to 400 at the fly
^^this assumes AFRs of 11.2-11.5
that puts the 3071R at an almost perfect match. I dont think you'll find a turbo that will spool like everyone wants and still play nice at 55lb/min.
i couldnt find the Esmeril compressor chart, if it was ever posted - i think it's gone now.
Last edited by paulmasoner; 01-17-2009 at 12:05 AM.