question on smg

how on earth does the smg work for the 360 / 430 model, i understand the concept, sequential manual gearbox, but how does it work when downshifting, does it have a slipper clutch or does it just bang down gears, say your in 5t gear and you knock it down to 3, does it slip and slower introduce 3rd gear or does it just hammer down to 3rd,

 

Not sure I understand the question. You understand that this is a 6 speed manual gearbox and it has a standard clutch. Both the clutch and shifting are run by computer. If you drop two gears it disengages the clutch, rev matches, shifts down two gears, engages the clutch again.

 

sure you understand the concept ?

first off, ferrari does not use a sequential. it's a standard gearboy with automated clutch and shifts. ie no torque converter as in an automatic. just an automatically actuated clutch. in a sequential you have to shift 1-2-3-4-5-6 and 6-5-4-3-2-1.......ferraris f1 you can shift 6-4 or 6-3 or whatever, as the clutch disengages, sets in gear and then engages.

 

The F1 gearbox is NOT a sequential transmission. True sequential transmissions are used in motorbikes and racing cars. The only way to get from 6th to 4th on a sequential is via 5th, even if only briefly. On a 6 speed transmission like on a F1 355/360/430 it is possible to go from any forward to gear to any other forward gear with no intermediate gears in between. It's easiest to think of the F1 gearbox as a standard 6-speed manual gearbox with a computer handling to movement of the gear-lever and the clutch.

 

then why is it called smg sequential manual gearbox, it says it right in the f430 manual, the paddle shifting. the right side paddle is for going up in gears and the left is for downshifting, my question is when you downshift with the paddle you have to go down the gearbox 6,5,4,3,2,1. what happens if your doing 150mph, in 6th and then you shift all the way down to 2 gear what happens does it overrev into the red or does it slowly engages with the use of a slipper type clutch like on my motorcycle.

 

when you hit the paddle for downshift you have to hit 6,5,4,3,2,1. 6 to 1 you have to hit the paddle shift 5 times no matter what. its impossible to hit the paddle shift 3 times to get from 6to 1

 

I've never seen it called smg manual, but I'll assume that it does; although that's the term that BMW uses for their automated-manual.

The paddles allow the sequential selection of gears -- this does not alter the fact that it is a regular 6speed non-seq tranny.

The F1 computer will not allow a downshift that would result in rpm exceeding a certain rpm (my guess would be red-line at 8500 on a 360/430).

The problem might be just one of terminology and an industry refusing to settle on an agreed definition of what a sequential transmission is. In the computer industry, every one standardizes on 1,024 bytes constituting a Kilobyte (KB) ... except the disk-drive industry which standardizes on 1,000 bytes, because this makes their disk-drives appear bigger (it compounds when going to MB and GB and TB). There is a standards organization that has declared that 1,000 bytes *is* a KB and 1,024 bytes should be refered to as KiB. NO ONE in the computer industry uses that, and yet that's the published standard.
I draw this parallel because it wouldn't surprise me that the definition of "sequential transmission" might, by popular terminology, include any transmission where it *appears* to be required to access the desired gear by going up/down one gear at a time. From an engineering point of view though, there is a big difference between a sequential transmission and an ordinary manual transmission.

 

i agree its marketing semantics.

ps: remember 8" floppies?

pss: remember cutting a hole in single sided floppies to make them double sided so you didnt have to pay extra money?

oh man...i am going to get flamed now for being nostalgic. (i remember learning PJL and JCL on an as/400 and loading magnetic tapes & playing with ticker tapes that my old man brought home)
Image Unavailable, Please Login

 

it won't let you over-rev/'money shift" the engine and blow it up. any sequential-type gearbox [F1, e-gear, SMG, DCT, DSG, PDK] is pretty idiot-proof.

 

Dude, I'll take your nostalgia and raise you 1650bpi.

My first program I entered was on a hex keypad for a computer with 256 *bytes* of RAM. Yes, that's 0.00000025 GB.

My first non-volatile storage was 300baud cassette. To give you idea of the speed of this storage, a 200KB typical image on this site would take around 1.5 hours to store or retrieve.

Remember 8" floppies ? They were a dream come true! A massive 1.2MB of storage -- a huge upgrade from the 88KB/side 5.25" floppies I had been using previously!

 

ok so the ecu or on board computer wont let the downshifting over rev. my question was what type of mechanism wont let it over rev. slipper clutch?

 

Didn't you read, there is no viscous coupling in the Ferrari F1. It won't over rev because it won't shift gears.

 

The Magnetti Marelli Transmission Control Module (TCM) it is the (ECU) that manages the Transmission/clutch. It receives the gear shift command from the driver. If the gear selected would cause an over rev, it will not execute the command to the gear that would cause over rev. It calculates the maximum potential engine RPM of the selected gear with the electronic throttle plates wide open, if the calculation is out of the programmed parameter the command is not accepted.

The (TCM) is responsible for clutch management as well. Your question was directed primarilly towards downshifts. The (TCM) is connected to other system management ecu's via Control Area Network line (CAN). The (TCM) receives many different inputs, Car speed, individual wheel speed, engine rpm, trans. rpm, throttle position, brake pedal, gear selection, etc. Commands are executed based on logic compiled between the ecu's in the (CAN). On down shifts, the (TCM) is concerned with wheel lock up and will slip the clutch as well as electronically heel & toe for the driver via electronic throttle plates in all efforts to avoid wheel lock up. So in answer to your question, it won't just dump the clutch. The speed of cluth full engagement varies on up shift and down shift depending on throttle position input and (CAN) logic.

Not easy to explain in writing. I hope this helps.


Adam

 

adam, thanks for the info that was perfect, it seemed like no one understood my question, i thought it was a simple question. thanks again,
im trying to get all the info possible on the 430 before i buy one, im trying to find out if i can actually take a workshop through ferrari to better understand the car and possibly try to take the tech class if they provide one.

 

http://www.autozine.org/technical_school/gearbox/tech_gear_manual.htm

Some basics about clutchless manual transmissions.

 

pfft: I remember wiring 360 computers in 1970...beat that.

rik

 

OK, mid-late 60's. Had to boot the computer by toggling in a sequence
of instructions on the front panel switches, and then you could use the
'improved' method of entering programs (once successfully booted) via paper
tape that was created on a teletype terminal. Oh yeah, and then
you got to use (if you were lucky enough to rig one up), an electric
pencil eraser to roll the paper tape back up.

I also understand that someone else will come up with something even
older than that.

I feel sorry for our kids who never had to use a rotary dial phone, or get
up off their #($#'s and change and fine tune the tv to another channel
(and there were only 3 or 4 channels anyway).

I am tearing up a bit right now, and will have to stop.....

Mike

 

twu, sooo, twu
Image Unavailable, Please Login
Image Unavailable, Please Login
Image Unavailable, Please Login

 

OK I'll take your 1650 bpi and raise you a 6502 instruction set. My old brain recollects that those big 8" floppies came before the 5.25"

 

Best thread hijack ever.

I learnt 6502 instruction set around ~1979. 8" floppies were never popular (or practically affordable/available) with microcomputers/hobbyist systems, but I got to use them on minicomputers starting in 1984. 32bit instruction set, 288MB disk packs the size of a washing machine, 8" floppies, fully interactive debugger .... heaven!