Active Aero -- A waste of time?
12-29-2014, 10:20 PM
#46
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One thing we noticed once back in 2013 was that we shifted the smaller of the dual elements on our wing to a higher AoA and actually went faster down the main straight of this shorter track. If my memory serves me correctly, we also measured the '2 notch' move to equate to an extra 300lbs of rear downforce. Our assumption was that the extra rear downforce allowed a higher exit speed out of the preceding corner therefore a higher top speed on the following straight. This would still be classed as anecdotal but thought it worth mentioning.
12-30-2014, 04:34 AM
#47
Rennlist Member
Yes that's possible Matt. I hadn't thought of it in that way. We were getting a lot more rear downforce than frontal back then. Do you hazard a guess at Jack's conundrum?
12-30-2014, 07:37 AM
#48
I know this is off topic but I have a question for Jack and I wanted to include an image, this was the only way I could figure to do it.
Jack:
I am very impressed with your car. I have turned my Euro spec SC into a fun street and track toy but not to the extent you have. I'm still trying to finalize the dash. I like the idea of extra gauges and would like to see a picture or pictures of what you have done.
My local track is Harris Hill Road in San Marcus Texas and the track configuration does not include high speeds and the aero I have on my Sc plants the car well.
Jack
Jack:
I am very impressed with your car. I have turned my Euro spec SC into a fun street and track toy but not to the extent you have. I'm still trying to finalize the dash. I like the idea of extra gauges and would like to see a picture or pictures of what you have done.
My local track is Harris Hill Road in San Marcus Texas and the track configuration does not include high speeds and the aero I have on my Sc plants the car well.
Jack
12-30-2014, 01:38 PM
#49
Race Car
Thread Starter
Right now, I think the tiny data sample I grabbed is practically worthless. I think the way to actually test it would be to do a series of controlled straight-line tests -- going from 100 to 130 in two different directions to compensate (as much as possible) for prevailing winds. That would mean taking a half a day and driving out to the middle of nowhere.
f4 plt, that's a beautiful car. It's true that aero is less essential at a lot of tracks -- especially newer ones. Willow is unusual in that six of its nine turns that are taken at 90+ mph.
I have four extra gauges. one is the display for my data logger, which I found a way to perch on top of my steering column in a way that doesn't block anything vital.
Then I have three others -- cylinder head temp, transaxle temp, and battery voltage -- which I put in the face of a later-model (for me) center console. None of it is especially pretty.
Since this picture was taken, I switched to a less-obnoxious holder for a phone.
f4 plt, that's a beautiful car. It's true that aero is less essential at a lot of tracks -- especially newer ones. Willow is unusual in that six of its nine turns that are taken at 90+ mph.
I have four extra gauges. one is the display for my data logger, which I found a way to perch on top of my steering column in a way that doesn't block anything vital.
Then I have three others -- cylinder head temp, transaxle temp, and battery voltage -- which I put in the face of a later-model (for me) center console. None of it is especially pretty.
Since this picture was taken, I switched to a less-obnoxious holder for a phone.
01-01-2015, 11:05 PM
#50
Rennlist Member
Junk data can live forever on the internet. So I did some more testing, and here's a comparison between two runs on the front straight at WSIR, one (red) with the wing going to low drag on the straight, and one (blue) with the wing remaining in a fixed position. The rear ride height sensor wasn't working, so this shows the front, which drops down when the rear wing is switched to the low drag position (note: the line going higher on the graph means the nose of the car was moving lower to the ground).
So that would seem to show that leaving the wing in the high-downforce (high drag) position on the straight meant losing ultimate high speed.
But then here's the flipside. This is the same two laps, but looking at the back straight. This time the high drag (and high downforce) speed starts out slower, but then catches up to the low drag run -- which doesn't make any sense, if the low-drag position is lowering a significant amount of drag.
The difference could be as simple as the prevailing winds during the two (sequential) laps. Or one of many other factors.
So the jury is still out...
So that would seem to show that leaving the wing in the high-downforce (high drag) position on the straight meant losing ultimate high speed.
But then here's the flipside. This is the same two laps, but looking at the back straight. This time the high drag (and high downforce) speed starts out slower, but then catches up to the low drag run -- which doesn't make any sense, if the low-drag position is lowering a significant amount of drag.
The difference could be as simple as the prevailing winds during the two (sequential) laps. Or one of many other factors.
So the jury is still out...
the question is , what is the drag and is it "significant"?
01-03-2015, 01:07 PM
#51
It all seems interesting and exciting until it sticks open and you go off WSIR T1 backwards at 130 mph.
If the folks in F1 can't get it right it is probably best that active aero has no place in amateur racing:
It is this safety issue that encouraged the POC to make active aero against rules - even in the unlimited GT classes.
Cheers,
If the folks in F1 can't get it right it is probably best that active aero has no place in amateur racing:
It is this safety issue that encouraged the POC to make active aero against rules - even in the unlimited GT classes.
Cheers,
