Veloce Raptor

This is why, when people ask George what pads he uses on track, his answer is always the baffling "Kotex Supers"...

Larry, imagine Sasquatch driving a 911...while smoking.

George A

That does it Dave!!! I've only got one thing to say: Would this be your car?????

BBBBBWWWWWAAAAAAHHHHHHHAAAAAAAHHHHHHHAAAAAAA!!!!!!!!!!!!!

G.

JW in Texas

Yeah, I still can believe the State of Texas would allow such an obscene personal plate. Dave, you should be ashamed.....

bsr_257

Now I'm really sorry I clicked on this thread...

Since I'm sharing a room w/ Bling Boy next weekend, I'll refrain from making any comments about the license plate.

Veloce Raptor

Nah...never see it before. The license plate looks like a bunch of 4th graders made it during lunch period. Uber weaksauce.

What sort of a Rennlister drives an M3 anyway?

George A

Noby, just walk away (really fast) if you hear the word "donations"!!!!!!!!!!

G.

Veloce Raptor

Dude, show some respect. That was presidential DNA.





In case the flatlanders on here can't tell, those of us in the Texas Crew have a great time being mercilessly sarcastic!

Greg Smith

Sarcasm? No!!!!

mpaton

David,
I believe you are correct. As Glen, Dave and George said, overbraking into Big Bend is common. That turned out to be the answer to my data logging all last year; overslowing, especially for Big Bend. The next DE I tried fixing it, and got to the apex just fine, but significantly faster, and smoothly applied the power in the same place. That turned out to be too much at that point. The extra speed meant that I had to wait a little to get to full power, compared to my previous slower entry.

Assuming similar gearing to my C2 996, I encourage students to try running Big Bend in 4th. It IS faster, but it feels much less stable. They need to understand that while we can say "power stabilizes the car" to a Green or Blue student, it's really a little more complex than that. If you don't have ultra high spring rates, then the weight transfer to the rear is going to squat the rear of the car and make the rear camber angles more favorable. Only it's not engine power that causes that, it's rear wheel torque. And when you are in 4th and not 3rd, there's a LOT less rear wheel torque available. So, aside from issues of avoiding overbraking, when you take Big Bend in 4th for the first few times, don't also try and enter faster. Just take the usual speed, usual line, but if you normally get to full power just before the apex in 3rd, then you should probably go to full power in 4th just as you turn in. All you're doing here is trying to get as close to the 3rd gear wheel torque as you can, only in 4th. As well as not squatting as much, it won't accelerate as much, so getting on power as soon as possible is the thing to do in 4th. But it doesn't feel comfortable as it does in 3rd, so take the time to get used to it. Then add in the faster entry.

In the GT3, it may be possible to be faster in 3rd with the rev limit 900rpm higher than the C2, but I think the gearing in 3rd and 4th is lower. In any case, I think it would still be good to practice Big Bend in 4th.

Gear changing mid corner isn't something to try until you really know your car. The car thinks you're lifting, and for 911s would be happy to respond in the usual manner. Once the rear suspension lifts, then that big moment of inertia is hard to rein back in, especially in a higher gear. Not what you really want at about 100mph.

However your car, even your 911 MAY be just fine with this, depending on how much power squat you get. Cars with much higher spring rates aren't going to lift the rear significantly as you come off throttle, and neither are those with really high rebound damping (which probably means at least double adjustables). I don't think my own 996 rear rates of 780lb/in is enough for this, so I doubt a stock GT3 is. I have driven and ridden in rear engined cars that were pretty much immune to lift off oversteer, and they are rather different. Mostly nicer on the track.

Michael Paton

David 23

Michael,
Let me get this clear, you are encouraging that I work towards entering BB in 4th, and get on the throttle as soon after turn in as possible. Hopefully that is earlier than I was able to do while in third. Is that correct? The times I have tried BB in fourth, I felt I entered the turn faster, as I was able to not overbrake the car as much in fourth, as I was while braking AND downshifting to third at the same time. However, I always felt I left speed on the track at track out when I was in fourth. So the trick is to keep the higher entry speed by not overbraking, then get on the throttle early enough to get the exit speed up to where I am not leaving exit speed on the track, correct?

mpaton

OK, I strongly suspect that 4th is going to be faster than 3rd in your car. I know that it is in mine, because my DAS tells me that. So is 4th going to be faster in 4th in your car? That depends, and you can try some things and find out. George has and Glen has had similar cars. I think Glen has had 4wd in his.

My main points are

1 overbraking for Big Bend happens often and has little to do with 3rd or 4th

2 When you enter Big Bend at the correct, higher speed, you will not be able
to accelerate as much from the apex.

3 Indeed you might enter BB faster and exit very slightly slower and still be faster on the complete lap.

4 To resolve those questions, you probably will need data aquisition.

5 BB in 4th feels less stable. Try it and get used to it before trying to make it be faster for you.

6 When you try and get used to it, remember that being in 4th means you should get on the power much earlier than in 3rd. It may sound dumb, but you need all the rear weight transfer you can get, and you won't get the accelerating that 3rd would have given you. At least that would be the 2wd recipe.

7 After you get used to 4th, and after you get used to slowing less, then try and see whether 3rd or 4th is faster. It won't be obvious, data aquisition will be very useful. 3rd will probably always feel faster on exit.

Take Glen up on his offer. Being in Austin, I don't often get up there apart from DEs but if you are at the October Maverick DE I'll ride with you then. Maybe even gather some data.

Michael

David 23

Michael,
I would love to take Glen up on his offer. I hope he will offer the advanced instruction to a group, of which I would like to be a part.

Your tips make sense, but I don't quite understand how (#3) if I exit slower, I can still have a faster lap? Even if the entry is faster. If BB leads onto the longest straight, isn't the exit to BB where I want the most speed as that carries more speed down the entire straight? I thought sometimes you actually give up entry speed to accellerate sooner to get a higher exit speed. Is that not correct? Just trying to get it clear in my mind.

I don't have data aquisition, but have AMB, so I get accurate lap times. I also usually video, so maybe i could stopwatch segments off the video tape?

I have to check to see if I can make the Oct. DE. This is a very busy time for me right now, and I might not make it. If I do, I will try to track you down and take you up on your ride along offer.

mpaton

David,

We're dealing with fairly small differences here. If you were 1mph slower at exit, same speed midway between apex and trackout, 1 mph faster at apex, and 2 - 4 mph faster all the way from braking point to apex, all relative to your usual "slow in fast out" method, then you still could be faster over a lap.

Fast onto the fast straights is important, but so is maintaining speed on the straights, like into Big Bend. It's a tradeoff, and quite a hard one to judge.

Lap times are useless for judging improvements at one corner at a DE because of traffic, and because if you were good enough to make all the rest of the lap time the same, you'd probably not need any of us to give you tips. Video with on screen time code is workable, but not especially easy.

Michael

jakermc

David -

My DL-90 confirmed that 4th was faster than 3rd for me. You are welcome to borrow the system and hook it up to your car if you like.

Seems like everyone is confirming what I wrote earlier in the thread. The only difference in my experience, and this continues to be true for me, is that downsifting does effect my entry speed. I am not able to effectively modulate the brake during a heel/toe to get the right entry speed. I am inconsistent. Carrying 4th solves the problem in BB, but I continue to struggle with Lil Bend, where I have to downshift to 3rd. For most of us, doing one thing (braking) is easier than doing two (brake and downshift).

A friend of mine with several national karting championships under his belt has also offered to come out for a coaching session. If you are interested, I'll let you know when we head out there next.

David 23

OK, makes sense. I wish I could get out on the track sooner! This weekend they are having some other events, so the only member time is on the new section only. I guess that would be a good drill to dial in some of those areas.