Sixth Gear

From: Shannon

Sent: Thursday, January 14, 2010 7:44 PM

To: Bruce Ledoux

Cc: David Quinlan; Travis Hill; Bob Doyle; Tom Sheehan; Kevin Buckler; Debra Buckler

Subject: Data Report

Hello all.  This is your friendly neighborhood data guy.

At several people’s request I have gone through all of the data from the weekend and found a few problems.  The main thing is shifting needs to be cleaned up.  There are many instances of poor shifting.  These will land you in the garage with a broken gearbox or out of the race completely with a blown motor.  For some of you I know we discussed specific issues, but I wanted to bring these to everyone’s attention.  Below are some specifics that I have found.

Here is an example of rushed downshifts.  The shifts occurred too early and put the motor above 9000 RPM for two of the shifts.  The worst of which was 9786 RPM.  It can be seen that this shift also caused the rears to start to lock up.  This shift was bad on two fronts.  The high RPM will kill the motor and the drive train stresses in the magnitude strong enough to initiate lock up will kill the gear box.

These next two are consecutive laps.  This again is a rushed downshift that could kill a motor on its own.  These are severe over revs (10008 RPM and 9930 RPM).  In a 24 hour race this will most definitely end a race early with a damaged motor.

This incident was a fatal incident that ended the gear box.  In this incident the throttle is not really blipped but held at least partially open while down shifting which results in the motor banging off of the rev limit while downshifts are occurring.  You can see this in the gears changing and the RPM staying at redline the entire time.

Here is an example of a bad downshift that will kill a gear box if repeatedly done.  The blip is done just fine with the gear shift, but the clutch pedal is released too slowly.  The blip and the downshift need to be done together.  There should be very little time between the blip and the clutch pedal release.  If it takes too long to release the clutch pedal, the RPM drop and when the pedal is released the deceleration forces are sent through the drivetrain as seen in the elevation of the RPM from below 3000 RPM to almost 7000 RPM.

Here is another extreme example.  In this one the car is allowed to go back down to idle. When the clutch pedal is released, the clutch engages and the engine shoots up to over 7000 RPM.  This is a big change in engine speed and the forces hit the gearbox the hardest.  This will break a gearbox in no time.

Be sure to get the blips done.  Do not down shift without the blip as it will land you in the garage.  Also be sure to make the blip and clutch engagement a seamless act.  Where I see problems in this case is when the blip is done and too much time passes until the clutch pedal is released engaging the clutch and putting stresses into the drivetrain as if no blip was done.

Slow down your thought processes.  Do a few laps at slower laptimes, but perfect on all shifts.  Downshift later so as to not over rev the motor.  This seems to occur as the laps start adding up.  Get the car stopped and slow the motor then downshift.  The brakes should be carrying the load here.  Also, don’t go down too many gears.  Know the gears for the turns and concentrate on going into the right gear.

Be sure to hit the blips perfectly.  Concentrate on getting the blip and clutch pedal release as close as possible.  This will help build the muscle memory or help you get the feel of it, which pays dividends when you are deeper into your stint and may not be as clear of thought.

If you have an incident like any one of the above, be sure to let your car chief know about it.  It will show up in the data, but the quickest way to know about it is to let the car chief know.  The sooner he knows about it, the quicker it can be dealt with, and the less damage it will do by not compounding the problem.  This race is won by staying out of the pits and garage.  If you have to sacrifice a few tenths to do this, it’s worth it.  If the car is driven as it was during the test, it will not finish the race.  As always, if anyone has any questions for me, please don’t hesitate to contact me.

Shannon Davis
Data Acquisition
The Racer’s Group (TRG)

www.theracersgroup.com

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On Jan 14, 2010, at 4:59 PM, Bruce Ledoux wrote:

Hi Shannon - this is great.  thank you so much.  are any of these charts mine?  how’s my data looking?  i’ve thought I have it whipped but would like to make sure.  please let me know. - b

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Shannon,

Thanks for the data tutorial. Can you put a data segment of A+ blips and  down shifts up for a comparison to the damaging blip and clutch release examples we see here. I would like to get a fix on when the good shifting starts in relation to brake input & correct time duration between down shifts. This is really good stuff. Thank you for these.

Regards - Tom Sheehan

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Guys,

pay REALLY close attention to what is going on here.  We are trying to be super pre-emptive to any issues & really manage your D24 experience as professionally as we can.

This is SUPER SUPER SUPER important.  You guys MUST fix this or I promise you 100%—you will NOT finish the race.

Whatever you have to do to go practice, learn, study–go get a stick shift from a buddy—whatever—you need to do it

Thx—we only want to help

—————————————————–

Kevin Buckler

Chief Executive Officer

The Racers Group/TRG

TRG Motorsports, LLC

Adobe Road Winery

www.theracersgroup.com

www.trgmotorsports.com

www.adoberoadwines.com

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Hi Team,

Let’s reframe this in a manner that “Stubby” really understands well.

1.  We’ve seen SOME of the teeth that the transaxle has to share with one’s bank account.

2. Check out the teeth that the motor has to share….it makes the trans seem like a mosquito bite.

3. None of this compares, however, to the team blanket party that happens to the driver if we lose the motor.  We can’t replace and continue the race as per the rule book.

Capiche?

Loose Bruce
(a.k.a “Stubby” to Kevin Buckler…..and “Yoda” to others)
Rolex GT #18
Guardian Angel Motorsports
Blog : Twitter : Donate : Fanpage

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