Power Runs/Dyno Plots

[enigma]

OK, here it is! Some plots I have done using the convoluted method of videoing my APEXi RSM, transferring them to my PC, going through them frame by frame to extract power and rpm data, putting this in to Excel, using the conversion from power at the wheels to flywheel power of:

wheel power * 1.35 = flywheel power INSERT INTO post VALUES (assumes 28% loss through transmission)

using the calculation

flywheel power * 5252/rpm = Torque

and then making some pretty plots!

So without further ado.........................

[enigma]

OK the first one, done on the M1 just after J25 Northbound................ :D

There are 51 data points if you are interested!

The run took 10.84 seconds and in that time I accelerated from 35-90mph

50-70mph took 2.72 seconds

Compare (http://www.car-videos.com/performance/speed.asp?Speed1=50&Speed2=70)

and

60-90 took 6.76 seconds. I include this as it gives me an idea that my 1/4 mile times should come down a lot! I have done 0-60 in 5.1seconds, add 7 seconds to get to 90 and you get 12 seconds...............my terminal speed at the POD was only 91.75mph so I should be storming!

[enigma]

Here is another one, this time launching in 1st gear away from some lights!

The power is 50BHP or so down due to the fact more losses are evident in 1st gear than in 3rd.

During this launch I did

0-30 mph in 1.8 seconds

Compare (http://www.car-videos.com/performance/speed.asp?Speed1=0&Speed2=30)

[zedy1]

thats great were u really pushing it to the limits dave

[enigma]

It was all straight line stuff with the foot welded to the floor........there is maybe 10BHP more top end and room for tweaking the curve............but I am happy for now! Well actually I very rarely run at this increased boost as there is no need if all you want to do is blow away boy racers!:D

[pjjohnson]

Good stuff. Nice to see the power holding up after 6000 rpm.

My guess would be that you'd be at around 13.9 to 14 for the quarter and just nudging past 100 mph, which is nice.

I see you've got a bit of 'torque spike' - could it be the torque converter catching up with itself perhaps ?

[enigma]

I would like to get in the 13s before I add any gas.......then I am hoping for 12s, high 12s maybe, but 12s none the less!

I am not sure what you are referring to when you say 'torque spike' but I guess it is the characteristic rapid rise and demise of the torque?

I dont see this as a problem, would be nice to hold it up a bit longer...........but this will come in time! :D

Got some motivation to build some turbo downpipes today, will have to see what the next week brings.

[pjjohnson]

Torque converters are sometimes called torque multipliers - very simply at lower revs they 'absorb' torque from the engine then release it - it comes as a lump - whoosh- thats what I have been querying on the other thread - the rubber band effect.

There is not always a direct connection from the flywheel to the wheels INSERT INTO post VALUES (as the torque converter is in between) so that can result in inflated figures at the wheels INSERT INTO post VALUES ( relative to what the engine is producing) when the whoosh comes.

It doesn't matter really because it still makes you go faster, but instead of the torque curve being as flat as the engine produces its got a low down bump or spike.

[enigma]

Hmmmmmm, there is no real evidence of a bump/spike though? The torque comes on strong to about 4000rpm and then tails off as expected? There doesn't appear to be anything on the graphs to suggest anything else???????? :Ponder:

[zedy1]

how about building some turbo pipes, you know the ones i want, that should give u INSERT INTO post VALUES (and me if u build ani=other set for me while your at it ) some extra power


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