Adjustments to alignment due to aero
02-20-2012, 02:53 PM
#16
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Sounds like this will be a fun experiment. I am primary concerned (now) with tuning at a macro level (drivability as Viking put it).
set it at max attack (8 degrees) and see what happens. If the front starts to wash out, I'll drop the wing to 4 degrees, then I'll drop to flat and then front aero to balance adding the rear back in.
-td
set it at max attack (8 degrees) and see what happens. If the front starts to wash out, I'll drop the wing to 4 degrees, then I'll drop to flat and then front aero to balance adding the rear back in.
-td
I'd go the opposite way starting out almost flat and observe how the front end feels.
Then, I'd increase the wing if the front end feels planted.
As others have said, it's very track dependent. I run almost flat at high-speed tracks like Cal Speedway with 19 degree banking, and at most I run 4 degrees on flatter high speed track like WSIR.
they can also make your car feel more planted at speed. It's a trade off, sort of like marriage....
Then, I'd increase the wing if the front end feels planted.
As others have said, it's very track dependent. I run almost flat at high-speed tracks like Cal Speedway with 19 degree banking, and at most I run 4 degrees on flatter high speed track like WSIR.
they can also make your car feel more planted at speed. It's a trade off, sort of like marriage....
After time in the Langley Wind Tunnel and at WindShear, you can see that the rear wing causes quite a bit of drag and has a much more pronounced effect on terminal velocity in exchange for that "cancellation of lift" as Mike puts it, whereas the front splitter can be quite aggressive but still not slow the car down much at all.
I see a lot of teams nail the car down in the rear, add more splitter until it's balanced, then begin to trim the rear out until the car is "lively."
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02-20-2012, 03:25 PM
#17
Mr. Excitement
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Hmm.
vMin at VIR T1, T4, Oak Tree and T14A is similar to Summit T1, T5 and T6.
VIR Climbing Esses can be similar to Summit T8-T9, if you come out of the Carousel quick enough.
VIR South Bend (T10) similar to Summit T3 and T10.
VIR T16-T17 similar to Summit T7-T8 in speed and importance.
In lower powered cars (doing 1:59-2:01 at VIR or 1:15-1:16 at Summit), vMax is similar between them but only once and for a very short time at Summit, so I would think you would run more AoA at Summit. I don't change it much, myself.
Trying to understand what you're saying.
vMin at VIR T1, T4, Oak Tree and T14A is similar to Summit T1, T5 and T6.
VIR Climbing Esses can be similar to Summit T8-T9, if you come out of the Carousel quick enough.
VIR South Bend (T10) similar to Summit T3 and T10.
VIR T16-T17 similar to Summit T7-T8 in speed and importance.
In lower powered cars (doing 1:59-2:01 at VIR or 1:15-1:16 at Summit), vMax is similar between them but only once and for a very short time at Summit, so I would think you would run more AoA at Summit. I don't change it much, myself.
Trying to understand what you're saying.
Less AoA at VIR. Light low hp by modern standards car with the aero cd of a chipped brick. Summit Point setting = planted at VIR. A couple ticks less AoA = lower lap times at VIR with a slightly increased pucker factor. Same settig at Summit = increased laptimes overall.My butt-O-meter reads the climbing esses as way faster and longer than the T7 8 9 complex at summit.
02-20-2012, 03:32 PM
#18
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more pronounced effect on terminal velocity in exchange for that "cancellation of lift" as Mike puts it, whereas the front splitter can be quite aggressive but still not slow the car down much at all.
I see a lot of teams nail the car down in the rear, add more splitter until it's balanced, then begin to trim the rear out until the car is "lively."
I see a lot of teams nail the car down in the rear, add more splitter until it's balanced, then begin to trim the rear out until the car is "lively."
I was lucky to find two articles about RSR wings and splitters online from racecar-engineering. As you said, the front splitter did not cause drag as the more aggressive rear wing angle did. I need to make a new, bigger front splitter after we put my car back together from the crash (most of the the old splitter is somewhere in the tire wall on the left of T15).
02-20-2012, 04:32 PM
#19
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My plan is to get the wing, set it at max attack (8 degrees) and see what happens. If the front starts to wash out and I can't overcome it with the bar,I'll drop the wing to 4 degrees. If it is still a bear, I'll drop to flat and then start adjusting the front aero to balance adding the rear back in.
Don't try to cover something up with another chassis change. One thing at at time. If the aero balance is off, fix that, don't make a chassis change to compensate.
I would also start with the wing as flat as possible and work up from there.
IMO, the LSD is where to start. The effects of a good diff are hard to beat, modified static lock up, combined with changes in ramp angle can really change a car.
02-20-2012, 05:23 PM
#20
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Definitely need the aero on both!
Checked my data. 2:01 lap at VIR, 1:15 lap at Summit
119 mph-127 mph through VIR Climbing Esses=9.5 seconds
78 mph-112 mph Summit end of Carousel to t/o T9=10 seconds
Last edited by ProCoach; 02-20-2012 at 05:39 PM.
02-20-2012, 05:43 PM
#21
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I would not use swaybar to over come an aero issue. The swaybar adjustment will change the low and high speed handling, the wing will only really come in at higher speeds.
Don't try to cover something up with another chassis change. One thing at at time. If the aero balance is off, fix that, don't make a chassis change to compensate.
Don't try to cover something up with another chassis change. One thing at at time. If the aero balance is off, fix that, don't make a chassis change to compensate.
02-21-2012, 09:30 AM
#23
Mr. Excitement
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No question that the Climbing Esses are faster from start to finish, but from turn in for the left on the flat (which actually has a slight crest as you approach the left curb) through turning to the right to apex T7 all the way to the braking point after settling from the crest at T9 is roughly equal in time to the Summit turn-in from the outside of the Carousel to apex T7 all the way to track out curbing approaching the Tub on the left after T9! Amazing!
Definitely need the aero on both!
Checked my data. 2:01 lap at VIR, 1:15 lap at Summit
119 mph-127 mph through VIR Climbing Esses=9.5 seconds
78 mph-112 mph Summit end of Carousel to t/o T9=10 seconds
Definitely need the aero on both!
Checked my data. 2:01 lap at VIR, 1:15 lap at Summit
119 mph-127 mph through VIR Climbing Esses=9.5 seconds
78 mph-112 mph Summit end of Carousel to t/o T9=10 seconds
As said I too follow the aero issues need to be ajusted via aero not via the susp rule of thumb.
