Mike, in order to "Rev Match" which most of us are not claiming, the ECU would need throttle control which we know it does not have since it's mechanical and there is no motor I'm aware of on the cable. But, the cable does what? - It opens the throttle bodies that allow air and fuel. I don't know myself what signals the injectors to provide fuel (I'll be looking into that). But, the injectors could provide fuel with a ECU signal, right? and as Brian stated, idle air stepper motors provide additional air. I really don't think fuel is being added.
None of those control the throttle, that's the problem. Even if the TPS is different, it's just a sensor (throttle position sensor), not a mechanism that will be able to modulate the throttle. Same for the ECU, the only thing it can modulate are the idle control valves which can't really rev the motor over 2k rpms. I just don't see any possible way the engine can get the revs up to 7k+ when downshifting at speed without the driver pressing the throttle. I'm open to it being possible, maybe the f1 cars have oversized ICV's that can provide a ton more air to get the revs up? I also don't see/hear much of a throttle blip in the above videos, but there are only one or two occasions where they show the driver attacking a braking zone at higher rpms - plus you can't see what his feet are doing. Still no conclusive evidence either way, but everything we know for sure (mechanical throttle linkage meaning the ecu can't work the throttle) says it doesn't blip the throttle. That really just leaves the idle control valves and from what I know, they aren't large enough to blip the throttle at higher rpms.
Dave Like i said i dont know why or how.but i do know it blips the throttle. I was just wondering why an F1 car have a different TPS from a stick.
I'm posting from 35k feet above the atlantic ocean, and from my view, the Earth is completely flat. There's no way this Earth is round. I can see it with my own eyes. It's flat. My view is perfect, and no matter what anyone says, I can see that the Earth is flat. There's no scientist, astronaut, or history book which can convince me otherwise. I'm just telling you guys, from my view, the Earth is flat.
I also find it humorous that you quoted that the article said the 355f1 had launch control. Read post #156
I cannot find these "Idle air stepper motors" Brian has referenced. What I did find is Throttle Potentionmeters and they are different between F1 and non F1cars. From the WSM, it appears these regulate the amount of throttle opening. Image Unavailable, Please Login
If the translation is correct, a potentiometer is just a position sensor aka throttle position sensor. It will provide no regulation to the throttle, that would be a stepper motor or servo. Number 24 here: http://www.ricambiamerica.com/parts_catalogs.php?M=FE&P=&V=diag&I=1454 Is the idle control.
Like Pete said, it's just a sensor - just read (better) the WSM on it's function. It's used to provide information for the ECU to calculate fuel injection time.
If it's truly is a potentiometer all it does is read the position. I'm guessing the difference between f1 and non-f1 is that the f1 potentiomer has an extra lead for the transmission ecu so it will get a direct read of the throttle position.
Why is the TPS different for the F1 car? Seems pretty obvious to me. TPS is telling the F1 ECU what state the engine is in and from everything I've read has an impact on how fast the clutch is engaged. For example, you are at a stop. You release the brake and step lightly on the gas. The TPS tells the F1 ECU the throttles are only partly open so it engages the clutch slowly to provide a smooth start and not bog down the engine. On the other hand, mash the throttle to the floor and the F1 ECU see WOT and basically side steps the clutch and the tires go up in smoke. I suspect this applies to all up and down shifts. For instance, the manual says that if you are down shifting to pass you should crack the throttle just as you pull the down shift lever. This would seem to let the F1 ECU know you intend to accelerate and has the effect of blipping the throttle and engaging the clutch rapidly to accelerate. On the other hand if you are in 4th and letting the car engine brake so the throttle is closed, the F1 ECU notes that and when you pull the downshift level I'm betting that since the throttle is closed the F1 ECU says engage the clutch slowly so as to spool the engine up without jerking the car. Add to this whether you are in sport of normal mode and that's another factor. I also agree with one of the other posters who watched the video Dave posted. I can not conclude anything from that video and I don't see how anyone could without having a clue what the driver is doing in the car when he pulls a shift. Like I said before, I have no experience with an F1 but it seems only common sense that if there is feed back form the TPS to the F1 ECU then what happens on up and down shifts is going to be very dependent on the exact position of the throttle. And the bottom line is it really doesn't matter because it does what it does and you can not change it by posting articles and videos or taking a pole.
John, I only posted that video so the "sound" we are hearing could be heard by the folks here. I agree, we have no idea what the driver is doing with the gas pedal (something or nothing).
The throttle pot is only a throttle pot. #24 is the stepper motor. That is a generic name. As you can see Ferrari calls it an idle control and that is just what it is in this application. When it increases air it is drawn through the air flow meter so fuel is added too. Even held wide open it probably only has the capacity to bring the motor to 2000 or so. Hardly enough to cause a rapid rise in RPM for rev matching. The degree of misinformation in this thread is exactly why this website is considered such a joke in the entire Ferrari servicing community and why it is frequented by so few of us. Argue on, some of you are providing mechanics from coast to coast great amusement.
I appreciate the sharing of information but I take exception to "argue on". It's a discussion board and we are discussing. Yes, they turn into arguments since people often can't understand valid points made by others. You, yourself have admitted to a rise in RPM and that confirms the "blip" (not rev matching) experience we have. That's all folks were trying to say. Like it or not, I walked away from this thread learning more about my car and that is great in my eyes.
Yes, and it makes adjustment to maintain idle rpm in response to things like extra load due to turning on the AC compressor or increased generator load. No? Agreed. I only post anymore for amusement and, perhaps, to put a little common sense in the argument. Like I said, I view FChat with jaundiced eyes. Oh, and this will be my 2000th post. My self imposed limit. Guess I'm done, unless I cave.
That is its purpose in life. The needs dictated by emission laws require a uniform idle speed and having it dip due to load from A/C, altitude, ambient temp, alternator load etc is no longer acceptable. We were told that as long as the system was there they decided to make it respond to the F1 system as well but they knew until electronic throttles were intro'd on the next generation car it would do very little. I always felt electronic throttles were over the top but they do make F1 systems and traction control work well.
Dave, a blip would only happen below 2000rpm given the setup, ie almost never when the car is being driven. It just can't let enough air in.
Those idle air motors , most likely Bosch units, internally , have a rotating motor that turns a shaft which changes the position of a valve. That process is not very fast and lacks the speed and precision that would be required to have any effect on engine speeds during a shift , especially the fast shifts of an f1 car. Sorry , if there is a throttle change , or what seems like a throttle change it is doubtful those idle air motors are the source.I have not looked at the Ferrari units , but they look identical to units i see every day on European cars of the era.
From the article: Ferrari in one swoop has made each of its 355 owners a Schumacher, at least where launch capability is concerned. What the system does is detect your launch intention via the throttle sensor in terms of rate of throttle opening and it will allow the engine to rev up to 6000 rpm and then dump the clutch at a prescribed rate for take up and the 355 will take off with tyres just lightly spinning enough to wriggle the tail, smoke the tyres and leap off the line on the way to 100 kph in just 4.7 seconds. The best thing is, it does this every time, ever so consistently. Sounds like launch control to me. It very well may do this, but if it does I don't remember reading anything about it in the owner's manual or ever noticing my car do this. Wouldn't surprise me if it actually did this however, but blip the throttle on downshifts, or rev-match like this article states? Never
