Help in electronic shifter

[Tareik]

hello all http://fsae.com/groupee_common/emoticons/icon_smile.gif
I am using kilktronic shifter and i need to know the current gear potion and the problems might I face while installation.


thanks in advance

[Owen Thomas]

Tareik,

Using my psychic powers, I can clearly see that your gear potion (position?) is Neutral. I suggest you leave it in Neutral until you read the instruction manual on this purchased system, and possibly contact the manufacturer with your questions.

[Tareik]

thank you for your time http://fsae.com/groupee_common/emoticons/icon_smile.gif

i know that I am in neutral now but I need any sensor to help me when I shift up or down to tell me the gear position at that moment.

thank you again

[Cardriverx]

Haha. Well maybe you should look at ways of fixing a rotary potentiometer to the shifter barrel... Just an idea =)


Originally posted by Tareik:
thank you for your time http://fsae.com/groupee_common/emoticons/icon_smile.gif

i know that I am in neutral now but I need any sensor to help me when I shift up or down to tell me the gear position at that moment.

thank you again

[Warpspeed]

A true gear position indicator for every gear is going to be very difficult to get working.

But you could build a "virtual" gear position indicator by simply using an electronic up/down counter connected directly to the shift buttons, and a single digit LED display.
Not as good as the real thing, but much simpler and easier to do.

A refinement would be to fit a neutral switch to the gearbox, there may already be one there.
Then use that to force the electronic counter back to to zero by activating the counter reset to zero function when in neutral.

[Repmud]

You should be careful with your engine as there is alot of witchcraft and wizardry that goes on inside of them. However, luckily for you, there is nothing too magical about checking it's gear potion.

The first step is to confirm that there is indeed current gear potion in the engine. This may be done by opening the 710 cap (if one exists on your engine) and inserting your measuring instrument of choice, be it dipstick or broomstick (function over form). If your stick comes out clean, good... these is no current gear potion in your engine. This makes it easy because you just need to simply fill it up with gear potion of your choice (*Please do not try to conjure your own gear potion concotions*), and it will now be your current gear potion. However, I have no advice if your stick comes out wet or dirty. Your mileage may vary.

Unfortunately, I reckon that the mixture of electricity and potions falls under modern alchemy. Finding recent grads in this field of study may be double double toil and troublesome, so that might be one problem you may face. Luckily, clean gear potion is an excellent insulator. On the other hand, gear potion with metallic flakes in it may not be your ideal solution.

If you thought gear potions and shifting were fun, you may also want to explore the realms of exhaust charms, combustible elixirs, and cooling tonic.


Originally posted by Tareik:
hello all http://fsae.com/groupee_common/emoticons/icon_smile.gif
I am using kilktronic shifter and i need to know the current gear potion and the problems might I face while installation.


thanks in advance

[Warpspeed]

Tareik, welcome to the Forum, and just ignore the idiots.
Check out the data sheet on the CD4192 up down counter. http://pdf1.alldatasheet.com/d...675/RANDE/4192B.html (http://pdf1.alldatasheet.com/datasheet-pdf/view/171675/RANDE/4192B.html)

This has an up clock, which would come from the up shift button.
A down clock which would come from the down shift button.
And a reset input that would come from the neutral switch.

It will probably need some contact debounce circuitry and input over voltage protection, but otherwise that chip is a very simple and low cost solution.
Hook it up through a decoder/driver chip to run a nice large seven segment LED display.

[Jay Lawrence]

Or, or you could run.... a manual shifter!!! http://fsae.com/groupee_common/emoticons/icon_smile.gif

Also, be aware that the suggestion by Tony is potentially dangerous, as it does not know whether you have reached the gear you were aiming for. Situations can easily arise in which you press the shift button but for whatever reason you mis-shift, but the gear position indicator saw you press the button and therefore thinks the shift was completed. Another way to do this which avoids the above problem is to base your gear position read out on a math channel through your ECU. This simply reads the engine RPM and ground speed and converts that information to display the selected gear (based on your gear ratios). Obviously, you require wheel speed sensors and if your wheels are spinning it won't work properly (this may be acceptable, depending on your application)

[Warpspeed]

Yes Jay, this a very simple ultra low cost idea, and I totally agree it does have it's limitations.

But after all, it is only a "virtual" gear position indicator, it is not going to stop the car or put you out of a race.

[kcapitano]

One possibility not mentioned would be to use a rotary potentiometer connected to the shift linkage.

You could write a (relatively) simple program to tell the pot at what angle a shift has occurred. Then you would be guaranteed to not lose track of what gear you're in via a missed shift.

The one problem it does have would be the start up value. It could lose track if you don't start in the same gear every time (like you spin out and are forced to start the car in gear with the clutch pulled).

Just food for thought

[Warpspeed]

The problem with most motorcycle type gearboxes is that all the gear changing goes on inside by some mystery mechanism.
There is really no simple external way of knowing for sure where all the shift rods and shift forks are individually positioned.

I am assuming an engine that has electric start will probably also have a neutral switch, and if it has, that at least can reliably tell you something.

Jay's solution of comparing engine rpm to output shaft speed with some software would definitely work, and probably be the best overall "technical" solution.
But even that has it's limitations.
When de-clutched, or stationary, it is going to either display garbage or go completely blank.
Trying to find neutral with the clutch disengaged would still be trial and error.

Oh ain't problem solving fun !

[jlangholzj]

If you really must know what gear you're in the only reliable way to do it is to read out your wheel speed and do a math channel based on RPM. Thats typically how all the aftermarket units achieve it as well.

Truthfully though....why do you need to know what gear your in? This may be a dumb question (since im not our team driver) but even when I do drive the car, its pretty easy to feel your way around the course. Our drivers seem to be happy with a simple neutral light and a shift indicator. Even without the indicator I've found that the more experience they get in the car, the closer to the optimal shift point they're at.

food for thought.

[Warpspeed]

Only time you might want to know, is during high speed braking for a very slow corner, or if you fumble and miss a gear.

If you are rapidly coming back down through several gears, it is always comforting to know what the gearbox is doing.

It's not like you have an H pattern floor shift that points to each gear.

Stabbing at paddles or buttons with absolutely no indication, can easily get you lost under driving pressure.

Even Formula One cars have gear position indication, and those drivers are certainly not novices....

It may also be useful during testing for data logging or telemetry.

[Tareik]

Thank u all for your help http://fsae.com/groupee_common/emoticons/icon_smile.gif