RE: PH goes drag racing

RE: PH goes drag racing

Author
Discussion

37chevy

3,280 posts

157 months

Saturday 15th April 2017
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Mr2Mike said:
Is there enough power to actually wheelspin on a Leaf? If not then what effect do changing tyre temperatures have?
Sorry that should have read pressures not temps. And I'm guessing not!

anonymous-user

55 months

Saturday 15th April 2017
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The leaf is consistent because the motor controller is directly controlling motor torque!

It hasn't got enough power at low speed (due to a lack of gears) to wheel spin, and the rate at which the initial torque is applied is also controlled (very precisely) by the positive torque ramp rate in its motor controller, so in effect the work done after the accel pedal is mashed to the floor is very very repeatable.


And, as long as you don't brake (just lift) after the run, you get back around 70% of the energy you just expended, so the battery isn't going to go flat that quickly either!

37chevy

3,280 posts

157 months

Saturday 15th April 2017
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Max_Torque said:
The leaf is consistent because the motor controller is directly controlling motor torque!

It hasn't got enough power at low speed (due to a lack of gears) to wheel spin, and the rate at which the initial torque is applied is also controlled (very precisely) by the positive torque ramp rate in its motor controller, so in effect the work done after the accel pedal is mashed to the floor is very very repeatable.


And, as long as you don't brake (just lift) after the run, you get back around 70% of the energy you just expended, so the battery isn't going to go flat that quickly either!
Agreed but of course drag racing isn't just about the car, it's about the nut behind the wheel and a fair bit of luck too.

*KT

603 posts

212 months

Monday 17th April 2017
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Just out of interest, and before everyone comments on the fact the Leaf won Sportsman ET, has anyone bothered to read the data on each round of eliminations and qualifying before passing any further judgement?

When you have, let me know what you think ;-)


http://www.eurodragstereventcoverage.com/santapod/...

37chevy

3,280 posts

157 months

Tuesday 18th April 2017
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*KT said:
Just out of interest, and before everyone comments on the fact the Leaf won Sportsman ET, has anyone bothered to read the data on each round of eliminations and qualifying before passing any further judgement?

When you have, let me know what you think ;-)


http://www.eurodragstereventcoverage.com/santapod/...
Spot on KT....yes the leaf won but wasn't number 1 qualifier, didn't get closest to their dial in (think that was me being 0.007 seconds off..while on the brakes...almost broke out!!!) and won the final with a lesser breakout.

While the results make it look as though the leafs win was easy...it was anything but. But the guys judged it well. The conditions changed over the 3 days and made a big difference to us all (even in my mini it was 4 tenths)...shocked me how much the wind made a difference, especially for the smaller cars.

37chevy

3,280 posts

157 months

Tuesday 18th April 2017
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http://eurodragster.com/timing/2017festivalofpower...

This is the interesting one for me. Take a look at the win margins closest race was 189mm, average win time of 0.18 seconds and closest to dial in was 0.007 seconds, you can't afford to make a mistake. Gill should have stuck to her dial in that she'd been running all day...wouldn't have broken out in the final and took home the silverware!

Camaro

1,419 posts

176 months

Thursday 20th April 2017
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You'll go a long way studying those spreadsheets, not enough people do.

TheMighty

584 posts

212 months

Saturday 22nd April 2017
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It just shows how wrong the idea of something with little power and very controlled torque application being easy to bracket race is.

Looking at Steve's full passes in the Leaf they ranged anywhere from 17.65 to 17.79 (a 0.14 window). Compare this with our skating around on the edge of adhesion runs which were from 7.74 to 7.82 (a 0.08 window). Steve qualified number 2 in his class with 0.025 over dial-in. We were 0.003 over for our number 1. Before anyone thinks that is a fluke, our last event we were number 1 with 0.001 over. Last year we qualified in the 0.00x's 3 times and only at one event all year we finished qualifying at over 0.02x. We have around 1000hp and nothing at all which actively controls the application of torque. The Leaf may be good, but there's a lot more to bracket racing than controlled torque application!