Gearing Calculator/Shift Approximation sheet

Goatkart

Registered
So, i figured i would toss together an "offline" version of the gearing command mph/gearing/tire combo calculator...

Secondarily, i decided to add a shift point approximation aspect...

I think its pretty straight forward to use, but here are some BASIC directions...

Things are color coded but NOT locked, so you can booger it up if you try :)

The salmon color cells are the ones you should be inputing information into...

Gray with orange type are all calculated values, you should NOT be entering info in there (unless your excel savy, then feel free to mess about)


Step 1:
Start on page 1, where you input your basic gearing information... A lot of it doesnt need changed for the average user... The big ones for the average joe will be tire size, and sprocket changes...

In case you need to know stock specs(gearing or tire size), those are on sheet 3 (to the best of my knowledge) for the gen 1 & 2 busa, as well as the bking...


On this page Enter in your Front Sprocket size, rear sprocket size, and tire size... That is all you need, unless you have for some reason changed internals on the tranny...

If you changed the tranny, the internal gearing as well as input shaft gearing are avail to adjust as well...


This will populate the MPH table, and plot each gear on the Chart next to it..

YAY... you now have MPH for each gear from 100 rpm to 12,500 rpm... (in an ideal world, with ideal tires, etc)


Step 2....

So you want to figure out the (ballpark) optimal shift point... The next pages are all about plotting a delivered torque value... Now these are HUGE estimates, so dont go quoting ANYTHING about them... it merely is trying to show the mechanical advantage of the gear as a torque multiplier through gearing... So no internet dyno's!


For this part you will need at the VERY LEAST a paper dyno sheet, however IDEALY we want a digital dynojet file that you can get from your dyno operator... These are for use in the WINPEP 7 software that dynojet has to offer...

The best sheet will display your dyno run from ~2000/2500 rpm to 10500-11,000rpm (depending on rev limts etc)... because of the nature of motorcycle torque curves (ie flat as hell) the information your looking for will almost always be right near your rev limiter...



IN EITHER CASE, the point is we are going to input the torque values for various RPM into the chart... the more values, the better the information you can get out of it... and NO CHEATING... cheating will just hurt ya, conservative is actually better, as shifting takes time, so your more prone to over shoot a shift, than undershoot it...

So, either go to the "plug n chug" version if you have a paper dyno.. you're going to want a ruler for this method, and a good eye...

For the manual method, mark off vertical lines every 500 rpm, until you reach the top of the rev limiter.... Now, use your ruler to determine the Torque for each value.... and enter that information into the various RPM values...

I have set the sheet up for every 500 rpm, but more certainly doesnt hurt, and requires just minor adjustments on your part to the sheet...

After this is entered, you will now have a chart to the right, with your delivered torque plotted for each gear....


For the WINPEP version... you are going to want to open your dyno run, making sure your torque curve is shown, with RPM NOT MPH... on the bottom..

Then go FILE, EXPORT DATA, COMMA DELIMITER

UNCHECK: FORMAT FOR PRITING, DISPLAY PAGE HEADER,RUN INFORMATION, CONDTIONS.

STEP SIZE: .100

CLICK EXPORT...


save this file where you can find it someplace handy...


Now, open the excel file, click on the 5th sheet "import area"... I left data there to give you an idea of what you want your final image to look like... Once you think you got it... hit ctrl-a then DELETE...

Now, depending on your version of office, this part may vary... but what you want to do is import the data into excel from the text file you made...

In my version it goes as such..

DATA TAB, FROM TEXT, NAVIGATE TO FILE, CLICK FILE, CLICK IMPORT

CLICK RADIO BUTTON FOR DELIMITED

CHECK THE BOX FOR COMMA, UNCHECK TAB,CLICK NEXT, THEN FINISH..

A BOX WILL POP UP ASKING WHERE TO PUT THE DATA, IT SHOULD DEFAULT AS $A$1 IF NOT, CLICK IN THE TOP LEFT CELL, THEN CLICK OK...


now, the data we need is the torque column...

First verify that the starting torque and ending torque values you imported, match with that of the plotting on the sheet called DELIVERED TORQUE WINPEP


If it does, go to your imported data, hilight the torque starting from top to bottom, copy it all (ctrl c) switch to your DELIVERED TORQUE WINPEP page..

click in the first rpm- torque cell (2900 is the default rpm) and paste (ctrl-v)


assuming all has gone ok, the chart to the right will replot the new data, and display delivered torque for each gear....


Continued in next post...
 

Attachments

  • gearingcalculator.xlsx
    76.9 KB · Views: 310
OK, so now you have your delivered torque and MPH plots... So how do we turn this into useful data...


First step.... Go to your MPH page.... determine your MAX MPH (theoretical) for each gear... Do this by finding your rev limiter, slide accross to first gear, note the mph for each red line...

so you should have 1st,2nd,3rd,4th,5th,6th.... (obviously some arent important for 1/4 mile etc)


Second step, you need to determine your approximate shift extension.... This is how far your RPMs drop after each shift....

To do this, take your MAX mph for the previous gear, go into the next column over (ie if your max mph in 1st gear is 70mph, move into the 2nd gear column) and find THAT mph in the next gear...

This is an approximated shift extension... it assumes you are NOT accelerating for the split second you shift, so your RPM in the next gear = the rpm for THAT mph....

This should give you a nice ball park estimate...

DO this for EVERY GEAR your worried about.... note which is which, since the busa has a close ratio transmission, its VERY LIKELY not the same....


Now we take this information back to the delivered torque table you populated...


What you should notice is, past a certain point your torque falls off... this is normal...

However, what you want to do to optimise shifting, is to make sure your always making AS MUCH TORQUE AS POSSIBLE be adjusting your rpm (thus torque) at the slight cost of mechanical advantage...



The big thing to keep in mind is that shift extension value you found now.... if you found a shift extension from 1st to 2nd of 2500 rpm, when you shift, your rpm will drop 2500 rpm, so your delivered torque will be at the RPM 2500 less than your currently at...


EXAMPLE: if you found a shft extension of 2500 rpm from 1st to 2nd... You decide i want to shift at 10,000 rpm... Your second gear RPM will now be 7500, so your delivered torque value will be what ever it says is 2nd gear, 7500 rpm...


NOW to optimise the shift, what you want is to shift in such a way that the value of the next gear (ie second) is HIGHER, than the current value in what ever gear your in...


EXAMPLE: If at 10,000 rpm, my delivered torque is 500, but i look at 7500 rpm in 2nd and my delivered torque is 600, i should be in second gear... as it will deliver MORE torque....


key here is torque = acceleration.... this all comes down to F=MA at the end of the day...


The biggest goal is to keep maximum torque delivered at all times down the track...




Now remember a few things... this is all idealized values... in a perfect world, with perfect shifts and perfect traction, etc....


It doesnt account for inertia, friction losses, slipping clutches, etc....

Remember, tach readings are not real time, they are lagged, etc...

Your shifting has lag.... there is time and error added everywhere!


This just gets you in the BALLPARK....


Some other interesting notes... This gives a very nice visual approximation of how close the gearing is for each gear.... You'll notice a big gap between first and second, and second and third, and then all the gears close from there on out...

Try inputing 1's for the torque on the plug n chug graph.... It might surprise you... (that will plot each gear of the transmission basically) at your rear tire....


I make no claims of absolutes, or accuracy, i merely distribute the information for people to use as they wish, in what ever way they wish.... I am not responsible for anything that happens because of this (unless you win, then it was all me)....


I can offer some limited support, but i obviously have a day job too :)

ENJOY!
 
OMG!!!

I guess I can't just ride it like I stole it anymore ???
Posted via Mobile Device
 
OH, and it should be virus/malware free, as my computer is, and it went from me straight to the server.... No worries there..

:beerchug:
 
OMG!!!

I guess I can't just ride it like I stole it anymore ???
Posted via Mobile Device



At no point did i say that :thumbsup:


I merely offered a second choice!



HELL, who knows, maybe this tells you that riding it like a bad bad donkey is the right way!!!




The ultra flat torque delivery of motorcycle engines often encourages it unlike cars which suffer quickly from over reving...

:cheerleader:



Also, a lot of FI setups dont fall off, so they are only limited by redline! CHOICES CHOICES!!!!


Just trying to offer the .org my nickles worth..... even if they dont want it!! hehehehe
 
Bumping this post as it came up... Since instructions are in it for usage, figured i would just knock it back up
 
Another chart. Looks like Excel. That is one thing wrong with or country is the Charts, Thats all they look at, And they don't mean squat. :laugh:
 
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