One for the chassis dyno blingers !
09-04-2010, 01:54 PM
#1
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One for the chassis dyno blingers !
Unbelievably RS Tuning appear to have stuck a small toe into the www water by releasing a few absolutely aweful videos of er...... pictures of a torque measuring gauge 
http://www.youtube.com/user/RSTuning.../1/D2Q0L7faaQI
As a bit of explanation to those who live by the chassis dyno curves produced from the rear wheels:
The engine in the video is on a Borghi & Sevari engine dyno rig with intake air temperature controlled by a water cooled intercooler with the data all used to provide the correct DIN corrected numbers which can be seen in the video.
The left hand top digits are rpm/10, the top right is KW (multiply by 1.36 for SAE hp - Flywheel corrected) and thebig gauge is measuring torque. Notice how the three sets of numbers interact according to tq*rpm/5252=hp (think that's right ?)
So the torque gauge swings to 800NM and the KW rise as the revs rise even tho' the torque remains reasonably static as the equation above works its magic...... really makes you think about chassis dynos doesn't it
http://www.youtube.com/user/RSTuning.../1/D2Q0L7faaQI
As a bit of explanation to those who live by the chassis dyno curves produced from the rear wheels:
The engine in the video is on a Borghi & Sevari engine dyno rig with intake air temperature controlled by a water cooled intercooler with the data all used to provide the correct DIN corrected numbers which can be seen in the video.
The left hand top digits are rpm/10, the top right is KW (multiply by 1.36 for SAE hp - Flywheel corrected) and thebig gauge is measuring torque. Notice how the three sets of numbers interact according to tq*rpm/5252=hp (think that's right ?)
So the torque gauge swings to 800NM and the KW rise as the revs rise even tho' the torque remains reasonably static as the equation above works its magic...... really makes you think about chassis dynos doesn't it
09-06-2010, 11:28 AM
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Well the gauge only reads to 800NM, but the video says the engine output 850NM. The gauge is therefore only accurate to 800NM, much like the boost gauge in the 993tt only reads to .8bar
I think you can make the best comparisons of engine output based on an engine dyno, since you can eliminate as many variables as possible as to testing conditions. However since our cars are driven on the road under non-static conditions, it is inaccurate to completely discredit a chassis dyno. It makes an approximation in output that is useful when comparing a car against itself in the tuning process. In terms of practicality, the chassis dyno is the only tool that people will have access to.
I think you can make the best comparisons of engine output based on an engine dyno, since you can eliminate as many variables as possible as to testing conditions. However since our cars are driven on the road under non-static conditions, it is inaccurate to completely discredit a chassis dyno. It makes an approximation in output that is useful when comparing a car against itself in the tuning process. In terms of practicality, the chassis dyno is the only tool that people will have access to.
09-06-2010, 01:52 PM
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What is funny is that this gauge has been in that panel since the late 80s when they were only managing ~600NM, now they can go off the end of it...
I think you can make the best comparisons of engine output based on an engine dyno, since you can eliminate as many variables as possible as to testing conditions. However since our cars are driven on the road under non-static conditions, it is inaccurate to completely discredit a chassis dyno. It makes an approximation in output that is useful when comparing a car against itself in the tuning process. In terms of practicality, the chassis dyno is the only tool that people will have access to.
Last edited by TB993tt; 09-06-2010 at 02:51 PM.
