Dyno Dynamics - Shoot out modes
Discussion
Is there anyone familiar with the various "shoot out" modes on Dyno Dynamics rollers?
Recently had my 135i on for a power run but had disappointing figures. Noticed later that the chart is showing "Shoot 2R" which is for a twin-rotor rotary engine. I understand it should have been on 6F for 6-Cyl forced induction, but unsure what difference this really made.
All I can find is that the modes affect the ramp rate but not to what degree or what overall effect this would have on results.
I'm not even hung up about the figures, even though I'm aware that's what it probably comes across like, just genuinely interested / curious.
Recently had my 135i on for a power run but had disappointing figures. Noticed later that the chart is showing "Shoot 2R" which is for a twin-rotor rotary engine. I understand it should have been on 6F for 6-Cyl forced induction, but unsure what difference this really made.
All I can find is that the modes affect the ramp rate but not to what degree or what overall effect this would have on results.
I'm not even hung up about the figures, even though I'm aware that's what it probably comes across like, just genuinely interested / curious.
Thanks for the input so far, i'm about 30bhp disappointed, I ran the same dyno bone stock months before at 326BHP on Shoot 6F and now with a downpipe and map 333. But there was a number of issues that could have led to this other than the shoot out mode used. I feel the fan used initially was too small, a bigger one was eventually used. Also the operator was struggling with wheel spin so there were many aborted / failed runs (not sure if related to the mode) and calibrating the speed of the dyno with the car seemed a struggle, holding it for several seconds at 5K RPM multiple times (is this normal?) all of which combined I feel just heatsoaked the standard intercooler.
Apologies for the poor quality pic, I didn't bother getting a printout.
Apologies for the poor quality pic, I didn't bother getting a printout.
Vixpy1 said:
Yes all of those things can be a factor, you should be looking at 370 plus with those mods, standard intercooler is crap and at best you get 2 runs out of these before they start to pull 20bhp plus when mapped. So its really a one shot or give up car.
Yes that's what I thought, but couldn't even get the one clean run. I asked what the IAT was but it wasn't being monitored so they had to get something to hook up to the OBD port, could see IAT was high, it was left to cool down for maybe 15mins IAT was dropping v slowly the whole time, this gave the best run of 333 but still down on expectation. AW111 said:
GregK2 said:
Yes that's what I thought, but couldn't even get the one clean run. I asked what the IAT was but it wasn't being monitored so they had to get something to hook up to the OBD port, could see IAT was high, it was left to cool down for maybe 15mins IAT was dropping v slowly the whole time, this gave the best run of 333 but still down on expectation.
Where was the dyno inlet temp probe?The graph shows inlet temp of 19 degrees (18 ambient).
Also ramp rate 100, which seems slow for a 300+ hp car. Driveline inertia is probably too low too.
I'm not at work, so I can't look up what it should be until tomorrow.
Cant help with the version either unfortunately, the picture was a few weeks back when I was there.
Thanks for looking into it, I'll be keen to hear what settings should be used when you get a chance to look it up.
AW111 said:
Shootout mode has it's origin in the early days of dyno competitions.
Until then, tuners were happy to work with the measured (roller) figures, with correction for atmospheric conditions.
Once people wanted "flywheel" power, and it became a number to brag about, we did a lot of correlation testing and came up with the original 6? classes.
Driveline inertia has an effect in that it takes power to accelerate the gearbox, diff, axles, wheels etc.
You can enter it manually, but of course that means you can use it to "cheat" to get a bigger power figure.
Ditto with ramp rate, correction method, etc.
So the idea of shootout is to lock down most of the variables so you're comparing like to like.
I can look at the shootout chart and know exactly what the variables are.
And that they're set for a n/a twin rotor rotary, with gearbox and tyres to match.
So what I can find looking at other dyno graphs that display the information is that the ramp rate is 150 in 6F vs 100 in 2RUntil then, tuners were happy to work with the measured (roller) figures, with correction for atmospheric conditions.
Once people wanted "flywheel" power, and it became a number to brag about, we did a lot of correlation testing and came up with the original 6? classes.
Driveline inertia has an effect in that it takes power to accelerate the gearbox, diff, axles, wheels etc.
You can enter it manually, but of course that means you can use it to "cheat" to get a bigger power figure.
Ditto with ramp rate, correction method, etc.
So the idea of shootout is to lock down most of the variables so you're comparing like to like.
I can look at the shootout chart and know exactly what the variables are.
And that they're set for a n/a twin rotor rotary, with gearbox and tyres to match.
TN is 3.47 for 6F vs 3.18 in 2R
What effect these variables would have on results is what I don't understand, plus as pointed out there are many other potential variables.
I think I just need to run it again at some point.
Edited by GregK2 on Tuesday 13th November 10:21
Mignon said:
The boost pressure curve on your engine must be interesting. I calculated it from the torque values.
I have a log I took myself if that helps? https://datazap.me/u/gregk2/stage2?log=0&data=...
Stan Weiss said:
GregK2 said:
I have a log I took myself if that helps?
https://datazap.me/u/gregk2/stage2?log=0&data=...
Are you able to export that data to say a CSV file and does it also have an each piece time stamped?https://datazap.me/u/gregk2/stage2?log=0&data=...
Stan
It gives time in seconds / ms. Selecting "Time" in the graph lets you see it also.
https://docs.google.com/spreadsheets/d/1dJdm-eH_hk...
Edited by GregK2 on Thursday 15th November 19:24
Mignon said:
My bad. I missed that the pedal position was 100% and the throttle is drive by wire so that only opens as much as needed. Assuming that was a flat road I obtained a perfect acceleration curve matching actual to calculated 10 mph increments to within 0.01 seconds for every increment. I've never actually obtained a curve as perfect as that right the way through a gear.
At the flywheel you have peak torque of 417 ft lbs at about 3000 to 3500 rpm and peak power is 357 at about 5000 to 5250. That's 303 bhp at the wheels.
From the intergoogles I obtained curb weight of 3420 lbs so plus driver I used 3600. Final drive 3.08, 3rd gear 1.58, rear tyres 245/35/18. MPH per 1000 rpm in 3rd is 14.53. Frontal area 22.4 sq ft, cD 0.33. Spec sheet is here.
http://media.caranddriver.com/files/2008-bmw-135i-...
The car is very traction limited, it'll light the tyres up without even trying so acceleration off the line depends on tyres and launch but on very good road tyres I get 0-60 mph in 4.7s. 1/4 mile is 13.26 @ 110 mph. Top speed is 171.
This is fascinating stuff and you got exactly the kind of figures I would have expected to see. At the flywheel you have peak torque of 417 ft lbs at about 3000 to 3500 rpm and peak power is 357 at about 5000 to 5250. That's 303 bhp at the wheels.
From the intergoogles I obtained curb weight of 3420 lbs so plus driver I used 3600. Final drive 3.08, 3rd gear 1.58, rear tyres 245/35/18. MPH per 1000 rpm in 3rd is 14.53. Frontal area 22.4 sq ft, cD 0.33. Spec sheet is here.
http://media.caranddriver.com/files/2008-bmw-135i-...
The car is very traction limited, it'll light the tyres up without even trying so acceleration off the line depends on tyres and launch but on very good road tyres I get 0-60 mph in 4.7s. 1/4 mile is 13.26 @ 110 mph. Top speed is 171.
AW111 thanks for taking the time to run that. there is very little difference in the simulated power outputs between modes. But would wheel spin issues be more likely as a result of the slower than desired ramp rate? I think we can deduce that the heat soak from failed runs had more of an adverse affect than the shootout mode now?
Mignon said:
I suggest the car owner check this next time he's out for a drive. Most car speedos read a bit high but those flashing slow down signs with built in speed detector are pretty accurate and a good way to check it.
I have added speed to the logging software I use so will get a 3rd gear log with it.Mignon said:
GregK2 said:
I have added speed to the logging software I use so will get a 3rd gear log with it.
Jaysus. Just see how fast the car is going at 3000 rpm like we had to do in the stone age. Not everything needs a bloody computer.
https://datazap.me/u/gregk2/speed?log=0&data=6...
I get 1,530 kg/ 3380lbs from various places including
https://www.pistonheads.com/gassing/topic.asp?h=0&...
https://www.1addicts.com/forums/showthread.php?t=6...
https://www.pistonheads.com/gassing/topic.asp?h=0&...
https://www.1addicts.com/forums/showthread.php?t=6...
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