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GT3RS in Car Brands Hatch England.. check this guy out

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Old 09-21-2006 | 12:26 PM
  #61  
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Originally Posted by Larry Herman
Anders, I don't quite understand what you are talking about. Maybe it's because I have driven 911s for so long, but I find that you have to stop trailbraking when the back of the car tells you to stop. If you are at or close to the limit, it is not a choice, it is a carefully executed technique that ends at the right place, at the right time in a turn.
Uhm, yeah.. I am disabled by two things in the discussions: to much time in 944-type cars and not good enough language skills in english..

To sum me up I am a Swede who loves to scrub speed of by flicking a car. I like my car to have a slight understeer tendency and lots of front wheel brake bias and prefer turbocharged engines because I feel that they are easier to balance through a turn and on turn exit than a naturally aspirated car with the same power.. I can't wait until next season when my car is back on the track and I'll get to do some real racing..

Perhaps we are all discussing this based on how we like a car to feel. It would be very interesting to meet IRL and exchange experiences and techniques.
Old 09-21-2006 | 12:37 PM
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No question that 944s are more tolerant of off-throttle work, and can be trailbraked farther into a turn, and then feel more stable with less throttle application in mid-turn (i.e. more momentum style driving). These rear-engined beasts like to corner with lots of throttle, although not as much now with the 996/997 platform.
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Old 09-21-2006 | 12:39 PM
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Originally Posted by forklift
Welcome Steve, thanks for your insights.

I dug up this article from an old thread written in 2001 I think. He doesn't mention what kind of throttle he goes to after braking.....constant like you mention or more to the floor like Larry, but I found it interesting:

"Ready for the rocking chair?
You can drive a Porsche 911 GT3 Cup like it was a Trans-Am racer, but you won't win that way
BY PAUL GENTILOZZI

You can drive a Porsche 911 GT3 Cup like it was a Trans-Am racer, but you won't win that way
Here's the deal. You're flat on the gas down the pit straight at Hockenheim, approaching 150 mph. When you get to the "2"
marker before the Nordkurve, hard on the brakes, you downshift from fifth through second. You feel the front end hunting while the ABS selects the best loading as you turn toward the apex, then you roll off the brake to the throttle and upshift to third just as you cross the outside curbing at the exit. That's how we do it, isn't it? If you're driving a 2001 Porsche 911 GT3 Cup using that technique- a technique I've used for 20 years in sedan racing in the United States-you're going to be near the back of the Porsche Pirelli Supercup field. How do I know this? I've been there. When I went to Indianapolis last year to do the Porsche Pirelli Supercup race during the Formula One weekend, there was no coaching of any kind. Like Al Unser Jr., Mario Andretti and all of the other Porsche neophytes participating, I drove like I knew how. But after five laps around Hockenheim with former World Rally champion Walter Roehrl it became painfully evident that the required technique for Supercup driving is much different from
what I'm accustomed to.
Paul Gentilozzi strapped in to the GT3.
The Porsche 911 GT3 Cup is a real race car, but it's a race car with the engine behind the transaxle. Its polar moment and weight
bias don't match the 50-50 norm we're accustomed to in Trans-Am; moreover, it changes all intuitive driving techniques for front- or mid-engine race cars. The 911 GT3 Cup requires a special finesse that starts when you pick that brake point at the end of a straightaway. Being the last guy to brake for the corner makes you the first victim. The rear weight bias inherent in all 911-type
Porsches becomes an enemy. I noticed Walter was two car-lengths earlier with his braking than I had been during my reconnaissance lap, but four car-lengths earlier on his throttle application. The key to driving the 911 GT3
quickly is initiating acceleration as early as possible after brake application. Think of it as a rocking chair. If you lean too far
forward, the weight is on the front of the legs and you have very little control or balance if you leaned the chair laterally. If you just
roll a little bit back in the rocking motion, you have the weight centered. Lateral balance and stability are much better.
We can't do anything about the rear weight prejudice in the 911. Early throttle application means longitudinal acceleration to help
propel the car forward without the inertia at the back of the car trying to pass the front in a lateral sweep.
For you Porsche owners who have hustled your cars around the streets or a racetrack, this probably seems basic. Yet to the
uninitiated, it's a 100-watt bulb shedding light on the dark mystery of driving Porsches fast. Once adapted to the style, you can really enjoy the 911 GT3. With Walter's driving lesson, and a little mental discipline, I almost forgot where the engine was. The 911 GT3 Cup became a well-balanced, pleasurable race car. I drove the car hard on the brakes and the gas, using all of the
engine, and it never faltered or complained. Heck, they even let real journalists drive it. If they couldn't break it, it must be
bulletproof."



Interesting post. I think that The writer was a little simplistic in his description (no offence meant). His origional error was carrying far to much speed into the corner at the end of the braking zone. This generally triggers the ABS which unloads the nose causing intial understeer. As he lifts to counter the understeer, the rear becomes light which leads to oversteer which he would then correct loosing more time. Once the car is finally settled he gets on the power. He has lost time on entry, at apex and on exit. I've seen it so many times with drivers of other formulae, especially single seaters. He does not mention whereabouts in the corner the power s applied after he learn't the lesson that fast in is not the way in a 911.. My point is that we all want an early power application, I get on the power as early as I can, I'm not holding up power application, but when a rear engined car is at it's limit of adhiesion at the front, you simply cannot plant the power or the front will push on as weight shifts off of the front tyres towards the rear, a driver must be patient and wait for the grip levels at the front of the car to incerase as the steering is unwound and less is asked of the nose of the car. The method of loading the nose through the frist quarter of the corner gives you an advantage of being able to carry more controlled speed into the corner using weight transfer to your advantage. Constant throttle element of the corner enables the weight to transfer from front to rear seamlessly. Simplistically, through a corner the ideal weight balance of the car would be 20/80 on turn in for front end grip, 50/50 at the apex and say 80/20 on the exit. A 911 can give you that if you use it's uniquie layout to your advantage. The amount of constant throttle applied depends on the corner. An off camber hairpin, would require more constant than a medium sweeper following a fast straight. Very fast sweepers wouldn't require any loading of the nose as understeer is not generally an issue, just throttle modulation through the corner ultimately flat by exit.

In essence I agree with the writer , get on the throttle as early as possible, but only after the car has done most of its turning and you have seamlessly transfered weight to the rear of the car. Stamping on the gas in a 911 while you are still asking it to turn is not quick and will definately loose time.

I bet you guys wish that you never asked now!

Steve R
Old 09-21-2006 | 12:43 PM
  #64  
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Originally Posted by TD in DC
I have been watching this discussion with great interest because it reminds me of a criticism of my driving that I received from an instructor who drives a GT3.

I am typically on full throttle from the moment I get off the brakes, which is not all that impressive since I drive a n/a 944. This instructor looked at my data and told me that if I was able to get on full throttle from the moment I got off the brakes, then I was not carrying enough speed into the corners. In other words, full throttle from the moment of transition is evidence of overbraking. She said that the acceleration curves of my data logger shows that she is right. It seems like you and Leh Keen agree with her, while Larry, the writer of the articles and many others around here think that full throttle is better for settling the car and increasing lap times. Am I at least identifying the potential source of slight disagreement correctly, or have I misunderstood some or more of the posts?

I haven't fully formed an opinion yet, although I am not sure how much more speed I could carry into the corners when I am already pulling 1.1 to approx 1.3 gs in these corners.

P.S. The examples are from VIR. The first trace is red (2.26) in April at 40-50 degrees F on RA1s. The second trace is black (2.27) a few weekends ago at 90 degree F on Hoosiers that have too many heat cycles. I think the black trace, although slower, shows that I am not driving a little better overall.

Here are a few data examples of what I mean, including a sketch to illustrate what she said my data should look like.

Thankyou, a perfect illustration of what I am stumbling to say.

Steve R
Old 09-21-2006 | 02:31 PM
  #65  
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Eight years ago I drove a 911 race car on a number of tracks owned by a driver for Alex Job Racing and used for local club racing. The car was set up by the chassis engineer for the Alex Job and ran on the same type of radial slicks run on the RSR's. When I first drove the car I used the typical early throttle and found that the rear tires would start to go off after a while. I was told to trail the brakes almost to the apex. It worked great the way this car was set up and caused much less abuse of the rear tires. I don't know the exact reason why the car was set up the way it was but it appeared to better balance out the work the tires did at each end of the car.

Leeds
Old 09-21-2006 | 06:08 PM
  #66  
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Originally Posted by Larry Herman
No question that 944s are more tolerant of off-throttle work, and can be trailbraked farther into a turn, and then feel more stable with less throttle application in mid-turn (i.e. more momentum style driving). These rear-engined beasts like to corner with lots of throttle, although not as much now with the 996/997 platform.
Larry, I fully agree with you (and your other posts). I've only recently started driving at the track 911s with frequency but have raced and driven all sorts of other cars in the past (FWD, RWD, Mid, front engine, etc.) and I have my own conclusions about what works best.

- 911s like "Parabolic" turn-in (decreasing radius) and exit (increasing radius), as you need to trailbrake them to get the most cornering load. In that process you increase yaw rate (rotation) and shorten the distance to the apex. On exit, they have tons of grip that allow full throttle earleir (sometimes before the apex) than in other cars, and they will understeer but if you open up the steering wheel it will drift out nicely in an increasing radius while at full throttle.

- The car is really hard to keep balanced at the limit in steady state cornering (long sweeper - constant radius) as trailing or partial throttle makes it very vulnerable to switch from oversteer and understeer back and forth.

For those with patience, I wrote something related to thsi discussion in our Blog comparing the data I gathered of me driving the 997S and Elise, and track buddies in their MCoupe and Cayman S.

http://axisofoversteer.blogspot.com/...out.html#links
Old 09-28-2006 | 03:06 PM
  #67  
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i forgot about this thread....


anyways.... here is my personal expirence.....

at infinion.... me and david ran within a tenth of each other one session.... looking at data.... i was 100% throttle 38% of my lap.... david was on 48% of his lap.... the 81 car drivers were 47 and 46%.. their times much slower tho.....


but me and david.. either way we drive... our styles are definatly different..... ran the same time... but me 10% less WOT... wich is alot...


soo........ wich way is better?............. mine of corse... cause i save more gas.. being WOT less.... DUH....


im just playing.. who really knows.... every car is differnt tho...






ps.. and the dood that said understeer is faster......... is just plain wrong.... seriously.. why would u ever think that
Old 09-28-2006 | 03:14 PM
  #68  
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I cannot stand understeer, it definitely slows my car down a lot...

Norm
Old 04-05-2007 | 11:08 PM
  #69  
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Every time a thread pops up about trail braking vs. early throttle pops up, I go back and re-read this thread. Some good info here....my own take is that there is one way to skin a cat and everyone has their own driving style...but trail braking allows a higher entry speed and average speed through the corner. As TD pointed out in Larry's shift thead we have been err, brainwashed in DE to get on the throttle as early as possible at all costs but..... that isn't necessairly the fast way through (depending on the corner). On my fast laps at VIR a few weeks ago I was finding myself getting on the throttle later than I had been (South Bend esp.) as my lap times dropped.
Old 04-06-2007 | 08:52 AM
  #70  
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Jim-
Thanks for reviving this thread. Since this thread first started I have completed my car and the comments made especially by Steve R. make alot of sense and bear keeping in mind even though I don't drive a Cup car.

It is interesting to compare the videos of him and Leh. They have dramatically different styles but both are very fast around the track
Old 04-06-2007 | 11:39 PM
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I would echo the earlier post regarding the way Mike Levitas likes to set up a car. On my GT3 Cup I have started to run the front sway full stiff and the rear full loose and then use this setup to try to trail the brakes into the corner apex before getting on the gas. I find I can brake later. and carry more speed through the corner and then use the breaks and the front weigth transfer to steer into the corner. Essentially trying to run up to the apex trying to feel what the the front outside tire is doing. Not a very technical explanation but it seems to be a faster way with the cup car rather than having it set up for slight oversteer. I have found that with this setup you have to really drive the car in hard under with the brakes for it to feel right. IMHO.
Old 04-06-2007 | 11:43 PM
  #72  
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All I can say about this is that for the folks who thought I was nuts for being ho-hum about the dude at The Ring who was all over the place who thought it was cool....

I thought THIS video was cool. Gives me a stiffy. Way better than someone being sloppy all over the track. This guy has it!
Old 04-07-2007 | 09:50 AM
  #73  
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Leh's post above begs the next obvious question: who conserves their tires more, or put another way; which style could be thought of as more 'aggressive'. Seems sort of logical that Leh may be carrying more speed into/through the corner if his and David's times are that close, yet time spent at wot is that different. Just thinking out loud. I'm an idiot.
Old 04-07-2007 | 06:07 PM
  #74  
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It would be great to do a sector by sector analysis in the data software; create throttle histograms for both drivers for each sector. The same could be done for brake pressure I suppose, giving one the inverse view of the situation. Create histograms for braking time/pressure.
Old 04-08-2007 | 12:01 AM
  #75  
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Not to be rude, but what is so exceptional about this video?
I am just trying to learn..........


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