Thunderbolt Videos

[Darren]

You can't go flat there Bob?  I was doing a slight breathe, no brake.

[bobt993]

Slight breath to set the front end.  When my car was 30hp down, I was flat out.

[George3]

 

Different car, but I was flat out.

[ninjabones]

As this is the single most important turn on the track, I spent a lot of time looking at data trying to find ways to improve.  This is data from one of my best laps during the race.  The red trace is throttle position. You can see my shift point coming out of the esses as the sharp initial drop.  I'm back on the throttle, then lift a smidge (down to 30% - no brakes) before turn-in and then back wide open. 

The lateral G tracing (yellow) shows oscillations between 1.2 and 1.3 Gs mid corner (mostly due to steering inputs, looking for grip at the traction limit).  A better driver would probably have a much smoother lateral G tracing (less sawing on the wheel mid corner) 

[Lainey]

Geez, this looks like a medication persistency curve. Glen, you are gonna have to hold a class to explain your graph when we get to NJMP.

[Darren]

Yeah looks like neat data!

[bobt993]

Glen I think your reading it correctly. When Cervelli drove my car at Summit and put down some laps.  Times were similar to mine (new car to him of course), but the G graph was much smoother.  I was braking much latter, but Chris started to get off the brakes sooner in the turn.  He also did a lot of 30% lift throttle applications in longer corners.  Tbolt has several places to apply this rather than hard braking/early throttle.

[AMoore]

Glen,

Great graphic. Very informative.

[ninjabones]

Okay, now if you want to get really fancy... here's a question for you.

This plot is two throttle traces at the last turn at thunderbolt (labelled #10 on the diagram) from two successive laps.  All the rest of the data on this segment is essentially identical.


What's the difference between these two traces and what is your guess as to the difference in speed at corner exit and at the end of the front straight?  Answer to follow shortly. 

[bobt993]

Glen,  without knowing the sector times etc there are a couple of scenarios.  Purple trace shows earlier throttle application at or near the apex (assuming you are dist X mode), but at a sacrifice of more lift which could mean less entry speed.   Speed being equal early throttle would yield increased max straight line speed.   Add in the lateral g and long g's for a better analysis.  BTW Jeff can take care of your CV joints.  I will be bringing a spare half shaft to Tbolt in.