From: skod@trenco.Eng.Sun.COM (Scott Griffith, Sun Lumpyware)
Newsgroups: rec.autos.sport
Subject: Re: F1: Schumacher's gearbox technique
Date: 15 Sep 1992 17:23:34 GMT
Organization: Sun Microsystems Inc., Mountain View, CA
NNTP-Posting-Host: trenco
Summary: more ramblings (long)...

In article 1992Sep14.203555.9608@stsci.edu, Matthew D. Lallo writes:

> Also interesting is how low the revs would drop before the big blip. If that 
> were the FW14 it would have shut itself down! 

Matt, you know this, but probably a lot of readers don't (since we
just had the fall influx of newbies, after all). Many race motors,
especially those at the very top levels of the sport, have so little
flywheel, such poor engine control mapping at low engine speeds, and
so much cam that they have no idle at all- the rookie survival
technique of "kicking in the clutch" at idle and allowing the gearbox
guts to come to terms with themselves will almost always instantly
result in a stalled motor. If your gearbox technique is not up to the
task, your lap would consist of a long series of fullbore runs,
followed by massive gear grinding with a stalled motor- and oh by the
way, a turn or two.

This is no great shakes if you're at speed, since once you get a gear,
the driveline spins the motor back up and away you go.  However, if
you have no real kinetic energy to use to get it going again (or no
clutch and really beat up dog rings in the 'box), your day can easily
be done- at the very least, you lose significant time mucking around
with the starter, assuming that the car you're in has one (in more
than name only). Handling unsynchronized dog-clutch gearboxes is an
indelicate art, but an art just the same.

This is what leads to stalled motors in spins a surprising amount of
the time. Once the car goes away, it is actually possible to remember
the old adage "when you spin, both feet in" (assuming, of course, that
you're not busy trying to somehow teleport out of your misguided
missile during its approach to Mr. Tirewall). This can allow you to
somehow save the car, and grab a gear, only to find out that the
engine gave up hanging around waiting for you to stop panicking and
_get on with it_ about 45 seconds ago. I hate when that happens.

What got Mansell in Canada, apparently, was the misguided belief that
the engine, once started, would never go back out of gear without the
driver's foot solidly on the throttle until the end of the race. I
suspect that that little gap in the mapping was closed that night.

I betcha Schumacher is left-foot braking- there sure as hell is no
clutch involved in his shifting, at least in this past race. Time to
break out the tapes of some of the other events and see if he's done
the same, or if this race was an aberration.

> BTW, the rev limiters in our Formula Renaults would cut spark under
> load but not do anything for overrevving while blipping in neutral.
> What's the deal?  Are there types that work in all circumstances. Is
> it harder to do for both instances or what?

It's a common problem with the "soft-touch" rev limiters used in club
racing. They cut some of the spark, and then a little more, and a
little more, as the revs build. Works great when the motor is under
load. Problem is that race motors have so little rotating mass that
even an _occasional_ spark at WOT with no load would send the revs up
to the moon- so the F1 boys must have a pretty sophisticated control
system.  Why not? It's not like they're dead-broke club racers or
anything...

The 2-liter cars I drove would limit themselves to 6600 under load,
but overblipping would result in 7500 on the tattletale (and a
hellacious racket!) every time. I would have liked a better limiter-
it would have saved me some money.

> I will sometimes skip down from 5th to 2nd via a
> clutchless downshift, but it is only smooth when I don't over-do the blip.
> In other words, if I stay in the tall gear until I'm at the right roadspeed
> for the new lower gear, and then blip just enough to mesh, but not over.
> Doing what we think Michael was doing, has, for me, resulted in a clean
> clutchless downshift with no gear crashing, but always produces a noticeable
> jolt to the car, at least in the Formula Renaults (and street cars).

Me, too. An overblip will always result in momentarily breaking loose
the rear tires. All of my gearbox technique has always been aimed at
not disturbing the grip at the rear of the car, and it's taken years
for me to progress from "hopeless" to "merely inadequate". Of course,
I've never yet had the delectible opportunity to go bash around for
the weekend in a car that doesn't even weigh 6 times as much as me,
with 750 BHP and 18" wide rear tires. I might do things a bit
differently under those constraints...

> But hey, Schu's fast and I'm not, so...I'd bet he knows what he's doing.
> He could be just doing what that particular car likes to do best.

Oh Lordy, yes. How I would love to have the opportunity to prove my
incompetence in one of those cars. I hope that I live long enough to
get a crack at something half as intense to drive...

In article BuLCC4.Grw@news.cso.uiuc.edu, Cory wrote:

>         Alain Prost downshifts in the same manner- straight from 6-3,
> only without abusing the driveline as much. He never engine brakes, just
> puts it in neutral, selects his gear, and drops the clutch...

Lots of guys at the top level of the sport skip gears downshifting,
and there are as many subtly different techniqes as there are top
drivers. And there's no way to pick whose is best, really- it's just
whose equipment lasts while being used that way, and who is smooth and
quick with it. Senna, for example (oh Gawd now I've done it- I said
his name), is smooth as silk getting his gears (or used to be, before
the car was made to get them for him), and then IMHO proceeds to louse
it up by squirting the throttle full-on 3 or 4 times on his way down
to the apex. He makes it work, and he's fast, and I frankly can't
imagine how he has _survived_ this long doing it.  

But that's why he earns umpty gazillion dollars a year doing it, and I
type for a living. There is some justice, for proper definitions of
the word "justice".

I skip gears while downshifting, or not, as the track and car require-
I don't even think about it much, it's simply a matter of deciding
between "I need second by the time I get to the apex over there", or
"I need second _NOW_" and let the spinal cord decide how many time the
feet need to twitch. 

And several other people have written in private email, in effect: 

> You feeb- it's JOHN Young Stewart...

Um. Yeah, I knew that. Mea culpa. In my heart of hearts, I knew I was
getting in trouble the minute I backspaced over the J.Y. and started
fishing for his real name. That'll learn me- and my wife, who is of
Scottish descent and takes these things very seriously, will probably
_brain_ me for this one...

-skod



--
Scott Griffith, Sun Microsystems Lumpyware
expatriate SCCA New England Region Flagging/Communications worker
(and sometimes driver, of anything that turns both right and left,
and can pass tech...) Return Path : skod@trenco.Eng.Sun.COM
Newsgroups: rec.autos.sport