Thunderbolt Videos

[geza]

It is difficult to make out the graph imbedded in the website, but I am going to take a stab at the purple line representing sooner application of full throttle, allowing greater terminal velocity of about 5 mph.
 
Looking at various videos, the question in my mind is, “What is the best way to take the octopus?�?. Your entry is different from others. Was this to take a more defensive racing line, or do you think it gives you better velocity going under the bridge?

[ninjabones]

Yes, purple trace shows earlier throttle application by perhaps just a few feet (yes, distance mode). 

Bob, you were able to see something I didn't, which is the slight extra lift which allowed the earlier throttle application.  The MPH difference plot (grey/green lower trace) makes more sense to me now.  I lost some speed on entry (upward blip on the trace) and then made it back up and then some on exit (downward blip and then stablizes at -3 mph).   End result is 104 vs 101 mph at corner exit. I carry that extra speed through the entire straight, which ends up making a difference of 127 vs 121 mph before the braking zone.

I added the two lateral G traces just to show you that they were essentially identical.

 




Half shafts are done.  Don't think it's worth spending the effort or time to make these 15-year-old ones servicable.   I need a back-up set anyway, so maybe we can talk to your friend about machining off the crimps and having the stub axle tapped for access bolts over the winter when I get around to ordering the new ones.

Geza, not sure which part of the octopus you are referring to.  I definitely take a more direct/tighter line through 7 (thanks to Darren for that little trick)... I sacrifice a bit on the sharp decreasing radius right hander, but usually make up a few car lengths on the guys using a traditional outside line.  Also, its definitely more defensive in that no-one can tuck there nose on my inside.  I also like to stay on the inside through the left hander (?#9) as there is a crown mid track (and again to protect the inside)... definitely more camber and grip on the inside. 

[JoeP]

Here are two laps from a high-res camera:

http://www.thunderousproductions.com/THUNDEROUS_PRODUCTIONS/Films/Entries/2009/10/14_NJMP_10_10_09.html

[betegh9]

JoeP wrote:

Here are two laps from a high-res camera:

http://www.thunderousproductions.com/THUNDEROUS_PRODUCTIONS/Films/Entries/2009/10/14_NJMP_10_10_09.html

Nice video Joe!! Look at Darren's line to and thru the octopus and you'll shave some time off your laps. Treat it as 2 skidpads, the first is a right hander decreasing radius and the second, a regular left hander. And I'm sure that you didn't skip school on the day when the teacher in geometry class was discussing the circumference of a circle. :dude:

[Darren]

betegh9 wrote:

Nice video Joe!! Look at Darren's line to and thru the octopus and you'll shave some time off your laps. Treat it as 2 skidpads, the first is a right hander decreasing radius and the second

I like that way of explaining it, that carousel really is a skid pad. Were you running a camera Nick? It looked like you were really running good.

Honest question Nick -- with your autox experience do you think it's better to come out of the carousel pushing/sliding wide at the exit? Or is it better to go a little slower and not slide?

The big decreasing radius is a great turn for driving and I think also for instruction. We teach straight line braking. We also teach that a tire has X amount of grip that can be used for braking or turning...in other words if we use 80% of the available grip for turning then we have 20% grip left for braking, theoretically.

In practice it gets over 100% -- that is if you are braking and turning at the limit then you are exceeding the total amount of grip you'd be able to get from just doing one of these things.

Thats why I think this long decreasing radius turn is great. I go full throttle in the 996 for about 1/3 of the turn, then trail off throttle, then get on the brake and turn. I ABS all through that section until I turn left. I don't lift totally off the brake until I'm just about ready to turn left. My car (2002) has 4-channel abs, I don't think it would work quite so well on an older car (99-01 996 or older car).

I take the turn almost the same way in my Acura, front wheel drive, no ABS, totally different car and that line works just as well. The entry into the carousel is totally different depending on car and driving style, in my opinion. With students, since it is a big skid pad, I like to ask them to try slightly different lines through there and we find one that seems to work for the car and that they like.

Turn 2 is another great turn. Have you noticed how difficult it is to make the turn if you turn in a hair too late? Again, like the decreasing radius, our traditional way of teaching runs into some challenges. We like to teach that late apexing is safer and in 95% of cases that is true. For T2 at Thunderbolt you really need to apex exactly at the right point, but if you apex late it's difficult to stay on the track! You run out of pavement!

When I started racing and really pushing hard I found that the truth of early apexing is that if you realize it exactly when you turn in, way before the apex, you can move the apex in further, into the curbing in many cases. T3 at Summit Point is exactly like this. If you turn in too late, it's hard to make the turn. If you turn in early you can apex up into the curbing at the apex and have no problem many times. I was suprised I had never learned that in DE. I think you'd have to be in the white group for that to make sense and by then you're solo

[bobt993]

I would tell you an even faster way around  T8-T9, but your in my race group now.

[Darren]

Who even knows what T8 an 9 are? Everyone seems to call the turns different names.

[JoeP]

Yeah, those are the "No Win Corners".  Every line feels crappy.

[betegh9]

Darren, I don't have a camera yet, I don't want to show my embarrasing mistakes ti everyone else and I am technically challenged. Actually, I am saving up to get the smartycam and hook it up to my ECU by via an ECU bridge, so I can get loads of information datalogged.
As to your HONEST question, I feel that holding a tight line all the way around, next to the candycane past the apex (turn 9) is the shortest distance to cover and also the shortest elapsed time. Once you crest the top, you literally have a near straight line thru the ESES where you can be flat out, lift shortly at the bridge and flat out again after turn in toward the front straight.

Have you tried to do a skidpad tight to the inside at X radius timing the lap? Then try to do the same, faster at X+7' radius (a car width+) also timing the lap? Just calculate the distance for both scenarios, then you can calculate the speed you must achieve to equal the time of the smaller radius. Using the same vehicle, and ALL other things considered equal, the longer line feels faster, but in reality it is slower thru the turn.

As for the other turns at Thunderbolt, T1 is where one should brake and downshift early enough to be able to be on the gas early and in the right gear toward T2. You better turn in at the right spot and reach the apex so you don't run out of RE at track out. T3 &T4 are similar, kinks at best, no need to slow down much. You be far from pulling 1G lateral in those turns. I really prefer the 2 additional turns that the chicane offers making it a bit more technical. T5 is the ONLY left hander besides the octupus (T9) that I discussedpreviously. If you carry LOTS of speed thru T4 and track out where you should, there is NO need to move all the way to the right to the turn in point of T5 because there is plenty of track out RE if you approach it at the middle of the track........and the best part is that you will cover lot less ground thru that turn. T6 is another kink, off camber, so turn in at the end of the candycane and apex not early, and the car will track out where it should. T7 is quite easy, one just has to allow the car to track out to the outside, and be a little bit patient staying out for another 20 to 30 feet and start turning into the first skidpad right decreasing radius accelerating to the end of the first set of candycane on the right. When the second strip of candycane begins, brake hard enough to slow the car, but also allow enough grip to turn in sharply (trailbraking). If you know the right feel, the front tires will grip and turn in, while the rear will rotate.(controlled rotation). Once the car is pointing toward the inside of T9, go pedal to the metal. This is probably the most difficult turn for most. One must have the right amount of steering and braking imput to accomplish this right, and fast, but when you get it right, you will smile and think of ME........... and if you don't get it right, keep practicing. I must say though that I teach green students differently since they do not have the skills to accomplish this without getting into trouble, Oh! except for those who have PSM, ABS, TC, PMS and what not!!
I invite any logical alternative to Thunderbolt because I'm still learning and trying new approaches.

[ZBlue996Kam]

Wow.
Such a long thread for this track. I can't wait to try it out this weekend.
Thank Darren for allowing this to happen. :dude: