Skip to 4:20 for chunk blowage... [ame=http://www.youtube.com/watch?v=469mi4UOVK0]YouTube - Top Gear - Pro-Drive P2 Test Drive and Stig lap - BBC[/ame]
Ha Ha, you got me there..... I was thinking I was going to see chunks of tire shooting off the car until I realized what Clarkson was doing.
Clarkson's stomach not-withstanding this is quite the demonstration of the effectiveness of the predictive nature of electronic torque distribution. For those that want to have the highest performance limits, it's a step in the right direction. For those that want a simpler, more directly coupled experience, it's a step backwards. Kind of like how modern engine systems can do rev-matching and faster shifting, it makes the car quicker, but traditionalists complain that it's less engaging.... Matt
Well it's all evolution. You use to have to hand crank a car to start it, then someone invented electric starters. Most cars didn't come standard with air conditioners. Try to find a car without anti-lock brakes. Do they even make hand crank windows anymore? I do miss the window wing vents on my 69 beetle, used to turn them full reversed and get free air-conditioning since it didn't come standard.
I wonder if some burley people biatched about the electric start because it meant that "wimps and pussies" could then drive cars... Like the new computer controlled dual clutch transmissions can make anyone a perfect shifter... Matt
I am going to approach this LSD issue from the perspective of a 2003 "S" owner that didn't get one from the factory. I didn't realize the real difference until I tried to claw my way out of turn 10 at Beaverun here in Pittsburgh. My right front tire was pouring blue smoke out of this 50MPH right-hand uphill switchback. Fortunately for me I already had installed a Quaife in my 2003 car and on this occasion was driving a 2005 MCS without an LSD. The difference was unbelievable, my car compared to this 2005 "S". The factory LSD would later prove to be a great option though probably not as good a the bullet-proof Quaife. Still worth the $500 though. Now to the E-diff. Hmmm, an electronic system that applies the brakes in a turn? I know it's differential braking and seamless, but I can't get comfortable with the idea of a car automatically braking in a turn. On the track, approaching an apex, I want to get on the gas and go! I don't want anything getting in the way of that exit speed. I am willing to be pursuaded if a dealership will let me drive one on the track.
In the case Graham presented above does the e-dif apply the brake to the spinning wheel to slow it down to the point where traction is gained again? Does it then modulate the brake on that wheel to prevent the loss of traction?
I learned to drive back in those days, on tractors, trucks, cars. On the tractors I was the young one, 9, and it made more sense to make me drive the mechanical bull, then throw bales onto the wagon. Mark
Yes, that's exactly how it works. As I'm sure you know, an open diff (which all MINIs have, now) will transfer power to the wheel which is the path of least resistance. When cornering, that means the inside tire. As soon as that tire loses traction, the vast majority of power is going to go there, and like track-toy said, that results in very little acceleration because all your power is turned into a smoke machine that looks strangely like a MINI wheel. When the car senses this wheel spinning faster than it should be compared to the car's speed or the other wheel, it applies the brakes to that wheel. By applying the brakes to that wheel, the wheel with traction becomes the path of least resistance and you accelerate. Like Dr. Obx said, it has serious potential because of the different parameters that can be inputs into the system. However, how well it works is going to be based a lot on how good the programming is. In theory, it's a great idea. Personally, I've found the execution of the DTC and ELSD to be good, too, but I also don't have nearly as much power as some others.
Not all systems use the brakes. Some use fancy differentials with electronics and the like inside... Matt
True Just curious, though... how many people have shown that the EDLC has resulted in significantly accelerated brake fade? I drove Sebring recently and didn't have any noticeable brake fade. That said, while I was driving the car hard, I wasn't threshold braking at every opportunity... but I also have smaller brakes than a Cooper S or JCW. Point being, I don't know that it's been clearly shown that EDLC results in a significant difference in brake performance. It certainly doesn't on the street or at an auto-x, and even track days I'm skeptical that a little brake application through a few corners is significantly contributing to brake fade. Logically, to me, the braking done when the EDLC kicks in would be relatively low "load" compared to threshold braking from 80-100mph after a straight. Anyway, I'm just playing devil's advocate to all the people who bash it without having used it or without actually understanding how it works... for instance, thinking it cuts engine power, which it doesn't. Everyone here seems levelheaded about it, though... skeptical or unconvinced maybe (like myself), but levelheaded and logical, so 1 point for MA vs. other sites.
I've heard from some that have had brake fade. I guess that you could brake deeper and drop some time! Anyway, it's not a fiction. It's also possible that once the benefit is found from better power on exit, that more power is applied and hence the system has to work harder.... That means more heat deposited when conventional systems would be cooling. Matt
Would they have had brake fade anyway, though? Obviously, the system adds brake load, but how much relative to normal braking load? Basically, I'm not convinced one way or the other. Just because someone has brake fade doesn't mean it was caused by the additional load of the EDLC, but then again, just because I *didn't* have brake fade doesn't mean that EDLC doesn't add significant load. It would really be interesting to see some sort of brake heat and lap time datalogging with two otherwise identical cars, one with and one without DTC, on the same day/track/driver/etc... but I'm thinking it's always going to be speculation on the effect of the DTC. All that being said, it's somewhat of a moot point in the sense that a serious "track car" is going to want an aftermarket LSD whether the car came with EDLC or a factory mechanical LSD. Oh, and yeah, I should be braking much later.
No matter how you slice it the brake based eDLC adds heat when the system would have been cooling. If the driving technique employed is close to the capacity of the system already, this added load can add more energy in resulting in fade. Matt
Agreed... my questions are: - Relative to the braking done to slow the car, how much heat load is added? - What is the relationship between the resulting brake load and the additional corner exit speed? Probably questions we'll never know the answers to.
Does anyone know if the Challenge series MINI's have to use the E-dif or is this one of the items that can be changed out? If they can't change it out then wouldn't it become evident that there was an issue with extra heat being generated as a result of the e-dif resulting in brake fading issues? Surely if it were a problem it would show up there?
There is no absolute answer... if you are light on the throttle on corner exit, it may not even engage! So the idea that there can be some sort of % load increase doesn't really make sense... It depends on how one drives and the technique that is used. I don't think it's in the Challenge cars, but don't know for sure. Any decent race car will have some brake ducting, and that will help as well. I think the ducting in the '11 refresh is there BECAUSE people were overheating the brakes. Matt
Like I said, I mean under identical circumstances and driving. That's why I'm saying it's really difficult to ever quantify that information.