Hey, Just came across the following; Not a bad explanation of the often discussed, but rarely understood, "engine maps". F1 Framework: F1 Engine Maps I do have a problem with it though...... The current regs say: Which is all fine & dandy. However; Sounds awfully like TC to me! Thoughts?...... Cheers, Ian Image Unavailable, Please Login
Traction Control...? Nah, its Variable Throttle Response Curve for Engine Speed Modulated Torque Control....that is COMPLETELY different! They are measuring engine speed, not traction. It just accomplishes the same thing....
Very good!........ However, I'd add that while what you say is true, they are definitely also measuring traction (or at least lack thereof). "If it detects wheelspin, torque is reduced"....... Cheers, Ian
The "negative slope" situation where torque decreases as RPM increases, in a non-computer controlled engine, is usually near or after the redline. Not where one usually drives. I can say I have only experienced that phenomenon inadvertently over-revving my dirtbike when I was a kid. On a 125cc bike it was like someone 'pulled the plug' on the power. I wonder if there is any mapping like that on an ENZO or LaFerrari, or if they don't need it because they have 'real' traction control.
Great thread Ian. This is precisely how turbo and ERS harvesting next year will control torque via the ERS system rather than via a throttle pedal.
It's some sort of crude feedforward traction control, ie there is no feedback loop actually measuring the slip and adjusting the torque to it. By the negative slope, they just throw some decreasing torque on it without really having control. The control performance of a real TC which takes the actual slip into account will be magnitudes better. (and btw, anyone who hands out engineering plots without proper axis labels and scale should be shot instantly. Twice for using Excel.)
OK. I'll go with that...... Need to check, but IIRC it is indeed any form of feedback loop that will draw Charlie's ire, +1 +1 I *almost* didn't post it for those very reasons! Cheers, Ian
Yes, I think it's a clever if imperfect TC substitute that meets the letter of the regs. But isn't that what F1 is all about? "Here's the specs, build the fastest car you can that meets all of them." Just like the much debated RB flexible wing. Everyone knows it flexes, but it passes all of the tests defined by the regs, so... Good to go. If you want to stop the "quasi TC" torque maps, write a specific rule that bans it. If you want to ban the non flexing but clearly wobbling wing, devise a test that will catch it. But... That will then force all of the teams to go and find another loophole to exploit. And multiple rule changes and constant tightening of regs designed to punish creativity would take some of the fun out of it. Don't you think? Very clever solutions both.
+1 "Real" traction control..... Apparently, Michael had quite a bit of say in development of the Enzo. Asked for advice on dealing with it he said, quote, "don't turn the TC off....". That's now 10 year old technology of course...... Cheers, Ian
Hell yeah!...... I didn't mean to imply it was "wrong". +1 +1 I love it!...... The sucker doesn't flex (per Charlie), but it definitely wobbles! He's yet to catch up to that one! As you said, isn't that their job? Couldn't agree more!..... "This is why we watch"..... Any *tiny* edge you can find *must* be exploited...... Cheers, Ian
That mapping isn't a very ingenious kind of TC, it's a crowbar approach because a normal TC system isn't allowed . If you presented that mapping to a normal driver on the road, you'd have your car back within seconds, I bet that it's horrible to drive.
^ Actually, it is quite good, and very customizable. Non linear throttles on RC cars makes a huge difference in controlability. This takes it a step further and creates a non linear engine map off of the non linear throttle pedal. What this does, is allow a driver to have a flatter "HP" curve when off throttle. This makes the output to the wheels more predictable. The gradual fall off in torque at part throttle melds the gears better together when shifting, when you up shift, you get less torque to the wheels, but with this map, it bumps up the torque at the lower RPM to help the power curve measured at the wheels to be smoother part throttle. Full throttle gives you everything you got. So its not as much a "traction control" as it is a system that lets the driver have a more predictable throttle response.
Indeed. Good point. [Although, we used it more on the steering servo than the throttle back in my day.] No doubt the "correct" amount of "expo" does improve drivability. "Modern" TX's can tune complete maps for just about everything of course - Probably even more sophisticated than the current ECU! Not quite true - Throttle pedal travel itself is linear, must be. This "line" can then be "curved" as shown in the plots by the ECU. Hmmm.... Not sure if your full sarcasm hat is being worn here..... I've always said there's plenty of innovation, just that it's more "subtle" these days..... FWIW, I think they're really pushing the envelope next season; Max power from the ES goes up from 60KW to 120KW and more significantly, max storage goes from 300KJ to 20MJ! That's a *lot* of storage. Exactly *how* they'll store it as left as an exercise for the reader - They initially struggled some to store 300KJ, 20MJ is whole other can o' worms. I think we'll see some real innovation once they get started. Cheers, Ian
Sure! In fact, I'd go as far as to say that's almost the definition of "pushing the envelope"..... Engineers of all disciplines prefer "incremental" steps, "pushing the boundaries" as it were. Revolutions (a whole new envelope? ) are much rarer. Still possible, but not often. Cheers, Ian
Somewhat related, but not "worthy" of a new thread, I just came across the following interview with a guy from Renault Engineering; An interesting thought..... I'd love to see 'em also allow VVT. Not quite sure why thats banned - Cost I guess? The full story; Renault explains F1 engine throttles - F1technical.net Cheers, Ian
Actually, I doubt that any car on the road has a pedal/speed -> desired torque map that's linear. I have some here which I unfortunately can't post, but they're highly nonlinear, calibrated for whatever the manufacturer wanted to have in terms of throttle response, driveability and so on.
Makers often set the initial pedal to throttle ratio high to enhance the feeling of snappy acceleration.
IMO, I think it's depressing, as fans, that we're nerding out over **** like this. We should be talking about the new spec engine Ferrari is bringing for the next race, or how Alonso thought the car felt while testing at Maranello...not this crap
Don't like it? Nobody is forcing you to join the conversation...... I for one find it interesting. That's as maybe. Bottom line, we can't. Move on. Cheers, Ian
A lot of the "sport" modes you find in road cars often do exactly that (and other stuff), and only to that map - "sport" means "tinker with the pedal mapping"
