mad power at low-ish boost...
10-01-2006, 05:53 PM
#1
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mad power at low-ish boost...
Howdy,
I did a power run this evening and saved a datalog. Car is set to 11psi but doesn't hit it (hits 10psi) due to my boost settings. So, from looking at the attached ,peak power is at 6224rpm, now reading the map value at this rpm would imply that I'm getting 217hp (with the 23hp for drivetrain losses added) at only 8psi (ish.. 155->157kpa) due to the pressure bleeding off . That can't be right surely...? Does anyone else get this kind of power reading?
Cheers,
Steve
P.S.Oh.. and yes I do use the same piece of road all the time and yes the power read from Dataloglab with these settings have matched the power given at dyno runs I've done exactly, so they are reliable.
I did a power run this evening and saved a datalog. Car is set to 11psi but doesn't hit it (hits 10psi) due to my boost settings. So, from looking at the attached ,peak power is at 6224rpm, now reading the map value at this rpm would imply that I'm getting 217hp (with the 23hp for drivetrain losses added) at only 8psi (ish.. 155->157kpa) due to the pressure bleeding off . That can't be right surely...? Does anyone else get this kind of power reading?
Cheers,
Steve
P.S.Oh.. and yes I do use the same piece of road all the time and yes the power read from Dataloglab with these settings have matched the power given at dyno runs I've done exactly, so they are reliable.
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10-01-2006, 06:26 PM
#2
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this is on a GReddy kit? Sounds about right. you should be somewhere around 180-190 at 8psi, could be more/less depending on the rest of the system. What are you using to record the hp, a G-tech pro?
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10-01-2006, 08:02 PM
#3
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Dataloglab but as I say I find it v.close to my actual output (took a datalog while on the dyno and the power levels matched once I'd added 23 for drivetrain losses).
Yup, Greddy, 370cc inj, begi intercooler, Link ECU, 2 1/2 inch exhaust from downpipe back
Yup, Greddy, 370cc inj, begi intercooler, Link ECU, 2 1/2 inch exhaust from downpipe back
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10-01-2006, 09:27 PM
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on a dyno you'd see the tq drop and the hp level off after 5.5k
Three greddy kit dynos:
https://www.miataturbo.net/forums/sh...9&postcount=38
BrgRacer - 15psi
Olderguy - 15psi
Mach929 - 6psi
but i'm sure its close, id assume the hp to be a little less.
Three greddy kit dynos:
https://www.miataturbo.net/forums/sh...9&postcount=38
BrgRacer - 15psi
Olderguy - 15psi
Mach929 - 6psi
but i'm sure its close, id assume the hp to be a little less.
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10-02-2006, 04:50 AM
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Heres a photo of my printout from 2004(not 2001 as said previous)... HP kept climbing till 6.5krpm
http://www.mx5ireland.com/members/sr...hat%20step.jpg
http://www.mx5ireland.com/members/sr...hat%20step.jpg
Last edited by Stevo11; 10-02-2006 at 08:49 AM.
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10-02-2006, 08:24 AM
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Well, horsepower would keep climbing, given it's multiplied against torque and RPM, but your torque would be leveling off and dropping after ~5500 RPM.
Also, there's more than 23hp in drivetrain losses. In the driveline, a portion of the losses are fixed and a portion are a percentage loss. In a stock-engined Miata, at redline, it comes out to ~25hp. On a higher-torque car and/or one that revs past the stock car's 7200 RPM, the losses are greater.
Also, there's more than 23hp in drivetrain losses. In the driveline, a portion of the losses are fixed and a portion are a percentage loss. In a stock-engined Miata, at redline, it comes out to ~25hp. On a higher-torque car and/or one that revs past the stock car's 7200 RPM, the losses are greater.
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10-02-2006, 08:41 AM
#7
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Yes, you are right, I was distracted by HP 
http://www.mx5ireland.com/members/sr...ng/202Dyno.jpg
My losses were 23hp (edited), must see if I can get other dyno numbers from people there that same day.
Anyways, so, this kind of power is what I should be expecting from say .. 8.5psi?
http://www.mx5ireland.com/members/sr...ng/202Dyno.jpg
My losses were 23hp (edited), must see if I can get other dyno numbers from people there that same day.
Anyways, so, this kind of power is what I should be expecting from say .. 8.5psi?
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