Watkins Aim data - what do you see?
#16
They look to be too fat as well. Ideally, there show be almost not time from full throttle to brakes, and then braking should be very sharp. FWIW, I am working on both of those elements.
#17
Addict
Rennlist Member
Rennlist Member
Originally Posted by cre8fun
Frank - Thanks so much for your time. Here's the result and now I can see, painfully, just how much coast there is going into the corners..for turn 1 and the bus stop, there's a good 3-400 feet from Vmax to significant braking.
- too much time between off throttle and brake
- off throttle looks too slow and "leasurely". They should be sharp
- simulated brake trace looks to be ramping up too slowly especially in T1, Inner loop and toe of the boot and T9
- you shouldn't need to brake for T10
- etc.....
#18
Instructor
Thread Starter
yup, off throttle to brakes - lots of time there. I feel that on the track as a place for improvement.
given it's a calculated brake trace from Long G data, I get there's noise, like I'm not braking in the outer loop, that's likely feathering the throttle till the camber comes in.
But the general shape of the brake application/release, I can see what I'm doing in the entrance to the bus stop and not sure what I could change (that being the biggest speed decrease, maybe it shows the most). So there's a small initial step which is transferring weight to the front tires, then there's a high spike which is straight line braking, then there's a step down in "pressure" as I turn in and carry the braking to the curbing. and during that last phase when the brake pressure decreases, the Lat G increases so G_sum is relatively constant. So in the braking into the bus stop, aside from bringing v_max closer to brake application, not sure what I should change about the "shape" of the calculated brake trace?
given it's a calculated brake trace from Long G data, I get there's noise, like I'm not braking in the outer loop, that's likely feathering the throttle till the camber comes in.
But the general shape of the brake application/release, I can see what I'm doing in the entrance to the bus stop and not sure what I could change (that being the biggest speed decrease, maybe it shows the most). So there's a small initial step which is transferring weight to the front tires, then there's a high spike which is straight line braking, then there's a step down in "pressure" as I turn in and carry the braking to the curbing. and during that last phase when the brake pressure decreases, the Lat G increases so G_sum is relatively constant. So in the braking into the bus stop, aside from bringing v_max closer to brake application, not sure what I should change about the "shape" of the calculated brake trace?
#19
Addict
Rennlist Member
Rennlist Member
But the general shape of the brake application/release, I can see what I'm doing in the entrance to the bus stop and not sure what I could change (that being the biggest speed decrease, maybe it shows the most). So there's a small initial step which is transferring weight to the front tires, then there's a high spike which is straight line braking, then there's a step down in "pressure" as I turn in and carry the braking to the curbing. and during that last phase when the brake pressure decreases, the Lat G increases so G_sum is relatively constant. So in the braking into the bus stop, aside from bringing v_max closer to brake application, not sure what I should change about the "shape" of the calculated brake trace?
- Top is speed, then actual brake pressure and then Matt's calculated brake pressure formula from Long-G and then GSUM on the bottom
- You can see that the calculated brake pressure from Long-G is actually a very good approximation to actual
- The chart on the bottom shows the trace for going into the Inner Loop with a high initial application and then a bleed off as you trail the brake into the turn. I am sure a pro would do better but the general principle would apply
- The last chart is a brake trace going into the toe of the boot
#20
Drifting
ProCoach and I disagreed about this a few years ago (same year I set track record in E, which has since been wiped away with the repave and Dan Martinson).
#24
Addict
Rennlist Member
Rennlist Member
The brake traces in my '69 911 and my 944 look the same. It's tough to lock up the wheels at initial application given their spinning momentum, but you need to bleed off brake pressure to prevent them from locking up, especially if you are trailing brake into the turn.
#25
Rennlist Member
#26
Originally Posted by coryf
Is this a pdk or manual? The throttle trace under braking looks very strange. Either hitting gas and brake at the same time or awkward throttle blips.
#27
Rennlist
Basic Site Sponsor
Basic Site Sponsor
Join Date: Jun 2008
Location: Durham, NC and Virginia International Raceway
Posts: 19,071
Received 3,216 Likes
on
1,852 Posts
Super slow (and LONG) throttle blips...
__________________
-Peter Krause
www.peterkrause.net
www.gofasternow.com
"Combining the Art and Science of Driving Fast!"
Specializing in Professional, Private Driver Performance Evaluation and Optimization
Consultation Available Remotely and at VIRginia International Raceway
-Peter Krause
www.peterkrause.net
www.gofasternow.com
"Combining the Art and Science of Driving Fast!"
Specializing in Professional, Private Driver Performance Evaluation and Optimization
Consultation Available Remotely and at VIRginia International Raceway
#28
Originally Posted by ProCoach
Super slow (and LONG) throttle blips...
Last edited by Thundermoose; 07-02-2018 at 08:29 PM.
#30
Addict
Rennlist Member
Rennlist Member
where
Act_Wheel_Angle = steering_angle/STRATIO
and
Ackerman = 7.969/ ((GPS_Speed*1.467)^2/(GPS_LatAcc*32.167))*57.2958
and
STRATIO = 22