Data v. Whiny Idiots (Throttle Response Edition)
#121
Re: Schumacher vs. Rubens:
Wow. Left foot braking allows him to basically virtually control braking balance very quickly. He is modulating the front (braking torque) vs. rear wheel net torque (braking torque minus engine torque). But he is nowhere near as choppy on the gas as Rubens is. Therefore he doesn't need as much "throttle response" as sjmarcy. :-p
Re: Senna.
He chops the gas like a rally driver. The effect of this is like PWM. If you go on off rapidly enough and modulate the durations of the on and the off, it emulates an analog signal.
Unlike Schuey who has good analog control over the throttle (positioning the throttle accurately to get the desired torque), Senna's foot oscillates. The NSX's driveline and suspension filters out most of the high frequency content (the chopping) and delivers an smoothed version of this right foot to the tires. Senna isn't demanding say, a jump from 20% to 80% torque in 100 ms. The car doesn't require that to balance it. The car needs a smoothed version of his right foot, and that is what the car delivers. If the car delivered torque to the tires and caused the car's attitude to change as quickly as his foot was moving, he would spin out.
So my contention is that Senna's driving style doesn't require superfast torque response to the tires, I will say the opposite is required - his style would work equally well on a turbo car.
In control system parlance, Senna's foot is a torque-demand actuator with a lot of 'D' in front of it, so it chatters a lot back and forth, and the system (throttle butterfly to tires) lopass filters this to produce a smoothed version of the torque demand.
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When I said my M3 was more difficult to throttle modulate at autox than my turbo miata, I believe it's for 2 reasons:
1) The M3 like any n/a car will develop near max torque at something like 50% throttle at 4000 RPM. The miata with TPS controlled boost target only develops 5 psi (wastegate can pressure) at half throttle, and it's programmed to linearly increase boost to 15 psi at WOT. So the throttle is less sensitive to movement in the miata. Its easier for my right foot to demand 5 psi (~60% torque), than in the M3.
2) Second, my right foot is more like Senna's in that it's not so good at immediately and precisely going to a foot position to get the torque that my brain wants (which Schuey is very good at). So my right foot chops like Senna's, and the turbo smooths it out to shock the tires less.
P.S. Despite accusations of troll-like behavior in this thread, this has been a good one.
P.P.S. Lolz at Sav's recent replies.
Wow. Left foot braking allows him to basically virtually control braking balance very quickly. He is modulating the front (braking torque) vs. rear wheel net torque (braking torque minus engine torque). But he is nowhere near as choppy on the gas as Rubens is. Therefore he doesn't need as much "throttle response" as sjmarcy. :-p
Re: Senna.
He chops the gas like a rally driver. The effect of this is like PWM. If you go on off rapidly enough and modulate the durations of the on and the off, it emulates an analog signal.
Unlike Schuey who has good analog control over the throttle (positioning the throttle accurately to get the desired torque), Senna's foot oscillates. The NSX's driveline and suspension filters out most of the high frequency content (the chopping) and delivers an smoothed version of this right foot to the tires. Senna isn't demanding say, a jump from 20% to 80% torque in 100 ms. The car doesn't require that to balance it. The car needs a smoothed version of his right foot, and that is what the car delivers. If the car delivered torque to the tires and caused the car's attitude to change as quickly as his foot was moving, he would spin out.
So my contention is that Senna's driving style doesn't require superfast torque response to the tires, I will say the opposite is required - his style would work equally well on a turbo car.
In control system parlance, Senna's foot is a torque-demand actuator with a lot of 'D' in front of it, so it chatters a lot back and forth, and the system (throttle butterfly to tires) lopass filters this to produce a smoothed version of the torque demand.
-----
When I said my M3 was more difficult to throttle modulate at autox than my turbo miata, I believe it's for 2 reasons:
1) The M3 like any n/a car will develop near max torque at something like 50% throttle at 4000 RPM. The miata with TPS controlled boost target only develops 5 psi (wastegate can pressure) at half throttle, and it's programmed to linearly increase boost to 15 psi at WOT. So the throttle is less sensitive to movement in the miata. Its easier for my right foot to demand 5 psi (~60% torque), than in the M3.
2) Second, my right foot is more like Senna's in that it's not so good at immediately and precisely going to a foot position to get the torque that my brain wants (which Schuey is very good at). So my right foot chops like Senna's, and the turbo smooths it out to shock the tires less.
P.S. Despite accusations of troll-like behavior in this thread, this has been a good one.
P.P.S. Lolz at Sav's recent replies.
#122
Here is Lewis Hamilton's data in a slower technical area of the course which I blue highlighted. There is less downforce available compared to the faster turns. Hence more driving is needed since the invisible hand is not pushing you down on the track as hard. Bahrain. McLaren F1.
Aggressive driver. I see throttle movement. And steering movement on the viddie. And left foot braking.
Like I've been saying...
Aggressive driver. I see throttle movement. And steering movement on the viddie. And left foot braking.
Like I've been saying...
#125
If you know turn one from Suzuka you know there's quite a few ways to take it. It seems Rubens is over slowing the car for the first apex, and then accelerating the car before braking for the second apex. From the data it looks like Schumi is trail braking throughout the whole corner and carrying more speed through the first apex. So what difference does that make? Well you can't really say that the differences in the data traces are solely from the difference in braking technique. Rubens is going at this corner in a totally different fashion (overslow, back on gas, brake again) then Schumi (trail brake through the whole corner) and that makes for a bigger affect on the difference in the data traces than anything. It seems Michael's approch is the faster way, but that doesn't mean Rubens is slower through the section because he left foot brakes. It means he's slower through the section because he's doing the corner wrong.
Also the author seems to downplay the fact that Rubens is on the gas sooner and has a higher exit speed. Obviously corner exit speed isn't everything but it is very important. Imagine if there were a one mile straight after this corner, over the whole distance Rubens might be faster even though he's losing 0.3s+ in corner entry and mid-corner. As we know, there isn't a one mile straight after this corner. There's a short straight and then a series of sweepers that in an F1 car are mostly flat, at least till the last one. Anyway, what am I rambling on about. Well, without knowing how quickly they both get through the section of track following this corner we can't really know who is faster, Michael or Rubens.
In summary, my big beef is the author choose the wrong data to prove is point. "This is the most spectacular example of Michael's unique driving style". WRONG, this is an example of two driver's taking a completely different approach at driving through a corner, regardless of driving style (that is, if those two things can be entirely independent). There are better examples out there of how Michael's unique driving style helped him at certain tracks be faster than Rubens.
I'm not trying to defend Rubens by any means, actually I think his right foot braking as really hurt him over his career. It hurts the teams he drives for too because they have to set the car up differently for each driver.
Okay, done rambling. Wonder if anyone will read this...
Back to your originally scheduled programming.
#126
When you look at the data from Andretti or Schumie in their primes, or Hamilton right now, you see that ultimately they make errors too. Just fewer of them and they catch them earlier before things snowball too badly. That is a large part of the uberfast hot shoes. Fewer and smaller errors. At times I can run, for sure, just as fast as multiple national champion drivers. But I am over my head and so a turn or two will have a slight error lessening my result. I can tell you that when I drive like that, it is pretty busy behind the wheel. Whether I am in a friend's 550 HP street mod Evo, a SC Miata, my own NA car, it does not matter.
Given the difference in throttle response some cars exhibit, this can help or hurt the ability of the driver to control the car when truly at 10/10ths. Since some strategies sacrifice control for output, this means that they can't quite reach the potential their straight line capability suggests. They can be fast and fun as hell of course. But if a mod has the potential to drop lap times by 5 seconds a lap and you can only find 4 even if you are Senna-esque then I am saying that part of the issue is related to throttle response. I have already established that at the very limit during technical maneuvers, many corrections need to be made. Some of those involved the loud pedal.
#130
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I, too, can take a 60 mph corner at 45 mph in my double digit horsepower car while stomping and releasing the throttle thereby demonstrating my throttle response prowess. **** a turbo.
#131
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"At times I can run, for sure, just as fast as multiple national champion drivers."
That's one of the funniest things I've heard in a while. You even added an unnecessary "for sure" like all the F1 drivers. I lol'd... until I realised that I was sitting at home on a Friday night lolzing at a guy I've never met on the internet, then I got sad.
Anyway, everybody has been going round and round in circles for seven bloody pages now. Somebody make it stop please!
That's one of the funniest things I've heard in a while. You even added an unnecessary "for sure" like all the F1 drivers. I lol'd... until I realised that I was sitting at home on a Friday night lolzing at a guy I've never met on the internet, then I got sad.
Anyway, everybody has been going round and round in circles for seven bloody pages now. Somebody make it stop please!
#132
"At times I can run, for sure, just as fast as multiple national champion drivers."
That's one of the funniest things I've heard in a while. You even added an unnecessary "for sure" like all the F1 drivers. I lol'd... until I realised that I was sitting at home on a Friday night lolzing at a guy I've never met on the internet, then I got sad.
Anyway, everybody has been going round and round in circles for seven bloody pages now. Somebody make it stop please!
That's one of the funniest things I've heard in a while. You even added an unnecessary "for sure" like all the F1 drivers. I lol'd... until I realised that I was sitting at home on a Friday night lolzing at a guy I've never met on the internet, then I got sad.
Anyway, everybody has been going round and round in circles for seven bloody pages now. Somebody make it stop please!
Then it only goes round in round in circles for three pages.
PROBLEM SOLVED!
#133
"At times I can run, for sure, just as fast as multiple national champion drivers."
That's one of the funniest things I've heard in a while. You even added an unnecessary "for sure" like all the F1 drivers. I lol'd... until I realised that I was sitting at home on a Friday night lolzing at a guy I've never met on the internet, then I got sad.
Anyway, everybody has been going round and round in circles for seven bloody pages now. Somebody make it stop please!
That's one of the funniest things I've heard in a while. You even added an unnecessary "for sure" like all the F1 drivers. I lol'd... until I realised that I was sitting at home on a Friday night lolzing at a guy I've never met on the internet, then I got sad.
Anyway, everybody has been going round and round in circles for seven bloody pages now. Somebody make it stop please!
Here is a display of that data. Note the time slip which shows relative result. I was able to use what I learned in a different car that day though, to good effect, so I could nail the final course elements. If you understand time slip then I have made my point. One thing about autocross is that you are on a new course and will never fully master it by the time it is gone. If the courses stayed up for some time or were permanent, times would drop.
On the thread itself you may want to have a word with Sav. He created the thread after all. And other keep referencing it in other threads, you may wish to speak to them too. After all more information and another POV are not needed everything is already known and fully understood. ;-)
Last edited by sjmarcy; 08-26-2011 at 04:30 PM.
#137
Did I miss the part where someone explained how an individual laptime/data plot was relevant to the comparison of NA vs. turbo throttle response?
<--- Wonders wtf is going on here.
For rolling on the gas information, see here: http://roadraceautox.com/showthread.php?t=35569 For those unfamiliar, Mike Skeen is a pro driver currently racing in WC GT and Grand Am something or other (and possibly more series, I'm not certain). He is very successful and fast, and is one of the smoothest drivers I've ever seen. His comments are towards the end of the thread.
P.S. Am I allowed to link to other forums? Not sure what the rules are on that here...
<--- Wonders wtf is going on here.
For rolling on the gas information, see here: http://roadraceautox.com/showthread.php?t=35569 For those unfamiliar, Mike Skeen is a pro driver currently racing in WC GT and Grand Am something or other (and possibly more series, I'm not certain). He is very successful and fast, and is one of the smoothest drivers I've ever seen. His comments are towards the end of the thread.
P.S. Am I allowed to link to other forums? Not sure what the rules are on that here...
#138
Sorry guys i'm a little late to the show but you're talking about the antilag on the end of the 1st page there...
It can be made at idle and can be made while shifting gears while running rich on throttle lift, iac opened fully and timing pulled back by 40-50 degrees into the negatives so the combustion happens when the valves open to keep the turbo spooled. I was actually trying that with my adaptronic before i pulled it however i dont think theres a way to retard timing into the negatives with it...at least its not possible using the ignition map.
It can be made at idle and can be made while shifting gears while running rich on throttle lift, iac opened fully and timing pulled back by 40-50 degrees into the negatives so the combustion happens when the valves open to keep the turbo spooled. I was actually trying that with my adaptronic before i pulled it however i dont think theres a way to retard timing into the negatives with it...at least its not possible using the ignition map.
#139
Did I miss the part where someone explained how an individual laptime/data plot was relevant to the comparison of NA vs. turbo throttle response?
<--- Wonders wtf is going on here.
For rolling on the gas information, see here: http://roadraceautox.com/showthread.php?t=35569 For those unfamiliar, Mike Skeen is a pro driver currently racing in WC GT and Grand Am something or other (and possibly more series, I'm not certain). He is very successful and fast, and is one of the smoothest drivers I've ever seen. His comments are towards the end of the thread.
P.S. Am I allowed to link to other forums? Not sure what the rules are on that here...
<--- Wonders wtf is going on here.
For rolling on the gas information, see here: http://roadraceautox.com/showthread.php?t=35569 For those unfamiliar, Mike Skeen is a pro driver currently racing in WC GT and Grand Am something or other (and possibly more series, I'm not certain). He is very successful and fast, and is one of the smoothest drivers I've ever seen. His comments are towards the end of the thread.
P.S. Am I allowed to link to other forums? Not sure what the rules are on that here...