Weird torque curve.
07-10-2014, 12:13 AM
#1
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Weird torque curve.
First off, the way i got the number. I got some of Shawns (refresh951) dynos and logs. put them im an excel file and averaged the numbers.
Maf volts converted into hp figures (from shawns logs) then converted to torque.(torque=hp5252/rpm)
I did this so i could reproduce the torque curves to see the powerband i have. I take these numbers as a grain of salt.
Both graphs are 3rd gear pulls. same formula, same logger, same sensors.
gtx3076R, m-tune, Tial 38mm, 3" exhaust (all open), FMIC, eBoost2 (at the time was still setting it up, note the curve)
The feeling (but dyno) felt exactly like the curve, not much of a throw back into the seat but i felt a gradual harder pull and tyres would break traction near peak torque.
Note***it tapers from 17 psi to 20 psi so it'll drop the top end down a little if it was at 18 psi. It was the only log i could find with this set up.
gtx3076R, m-tune, Tial 38mm, 3" exhaust (all open), FMIC, eBoost2, CEP cam, CEP head.
The feel (butt dyno) feels just like the curve, very liniar, more of a kick onto boost than before. at times i forget to change gear and hit limiter because i forget it's still building power. I could feel the drop on the previous setup.
Why would the curve be like how it is on the first one? Seems strange to me as most 944 turbos had a huge midrange torque and has a sudden drop of torque.
Overlay (i changed the colours to make it relevant to the representation.)
What i can see is with the upgrades: Peak torque is in a similar spot. More peak at the start of the boost curve. 200 rpm more lag, less drop off in torque, peak hp more to the right. looks as it'll continue if i had more rpm.
Note the boost isn't the same. i had roughly between 1-2 psi more with the older setup trying to configure it.
Heres a comparison with the cam and a 4° degree offset cam key
and here's all 3
Maf volts converted into hp figures (from shawns logs) then converted to torque.(torque=hp5252/rpm)
I did this so i could reproduce the torque curves to see the powerband i have. I take these numbers as a grain of salt.
Both graphs are 3rd gear pulls. same formula, same logger, same sensors.
gtx3076R, m-tune, Tial 38mm, 3" exhaust (all open), FMIC, eBoost2 (at the time was still setting it up, note the curve)
The feeling (but dyno) felt exactly like the curve, not much of a throw back into the seat but i felt a gradual harder pull and tyres would break traction near peak torque.
Note***it tapers from 17 psi to 20 psi so it'll drop the top end down a little if it was at 18 psi. It was the only log i could find with this set up.
gtx3076R, m-tune, Tial 38mm, 3" exhaust (all open), FMIC, eBoost2, CEP cam, CEP head.
The feel (butt dyno) feels just like the curve, very liniar, more of a kick onto boost than before. at times i forget to change gear and hit limiter because i forget it's still building power. I could feel the drop on the previous setup.
Why would the curve be like how it is on the first one? Seems strange to me as most 944 turbos had a huge midrange torque and has a sudden drop of torque.
Overlay (i changed the colours to make it relevant to the representation.)
What i can see is with the upgrades: Peak torque is in a similar spot. More peak at the start of the boost curve. 200 rpm more lag, less drop off in torque, peak hp more to the right. looks as it'll continue if i had more rpm.
Note the boost isn't the same. i had roughly between 1-2 psi more with the older setup trying to configure it.
Heres a comparison with the cam and a 4° degree offset cam key
and here's all 3
Last edited by Paulyy; 07-10-2014 at 02:43 AM.
07-10-2014, 04:03 AM
#2
Had the same "curious" results on on another car about 10 years ago. Non-dyno calculated pw/tq figures have little value imo. Only helpful to get curve shapes.
07-10-2014, 05:16 AM
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dyno runs cost from $150+ per session. Will go when car is back on the road. It's hard to make the time during work hours.
07-10-2014, 05:59 PM
#5
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Why are you so worried about the curve.
every dyno is going to give different (curves) results. unless you dyno at the same place and same day then then you do what your doing. Load on the dyno is different than load on the road.
every dyno is going to give different (curves) results. unless you dyno at the same place and same day then then you do what your doing. Load on the dyno is different than load on the road.
07-10-2014, 06:51 PM
#6
Drifting
This isn't from a dyno wheel measurement, the curve is extrapolated from another car, or charts/values from the previous owner. Can't tell from the information provided.