Spreadsheet for Gear Ratio Calculations
Thread Starter
Melting Slicks
Joined: Dec 2000
Posts: 3,407
Likes: 2
From: Carmichael CA
Spreadsheet for Gear Ratio Calculations
I saw several posts regarding rear end ratios, tranny ratios, etc. So, I thought I would share a spreadsheet I created to give me a better idea of what goes on during shifting, and to help me decide on a good set of gears for a Richmond 6 speed.
For example heres what a 4spd sheet looks like:
Here's what a 6spd sheet looks like:
The dark outlined bolt cells are where tire size, rear end and tranny gears, and shift points can be changed...all other cells should be left alone. The sheets will tell you what the top speed will be in each gear. The way you use it is to determine what the top speed you will have at the end of a quarter mile, figure out what gear you will be in, then design the gears so that the shift ratios will be as close to the same as possible for each gear leading up to the top gear, plus determine what your engine's horsepower curve looks like so that your shift point will drop your rpm down to where your next gear will have the same HP as before you shifted. Here's the spreadsheet so you can play with it: http://67.116.80.82/Vette/Files/Gear...lculations.xls
[Modified by Rockn-Roll, 11:22 AM 6/4/2003]
For example heres what a 4spd sheet looks like:
Here's what a 6spd sheet looks like:
The dark outlined bolt cells are where tire size, rear end and tranny gears, and shift points can be changed...all other cells should be left alone. The sheets will tell you what the top speed will be in each gear. The way you use it is to determine what the top speed you will have at the end of a quarter mile, figure out what gear you will be in, then design the gears so that the shift ratios will be as close to the same as possible for each gear leading up to the top gear, plus determine what your engine's horsepower curve looks like so that your shift point will drop your rpm down to where your next gear will have the same HP as before you shifted. Here's the spreadsheet so you can play with it: http://67.116.80.82/Vette/Files/Gear...lculations.xls
[Modified by Rockn-Roll, 11:22 AM 6/4/2003]
Burning Brakes
Joined: Jul 2000
Posts: 1,162
Likes: 2
From: Beaverton, OR
Re: Spreadsheet for Gear Ratio Calculations (Rockn-Roll)
Very cool. I hadn't thought about putting the info in a spread sheet... For some stupid reason I keep crunching these kinds of numbers and dropping them in a text file only to forget what tire size I used, or some other variable... Think it's time to whip out a spread sheet and start looking at my Desktop Dyno predictions :D
Melting Slicks
Joined: Jun 2001
Posts: 3,281
Likes: 6
From: NC USA
Re: Spreadsheet for Gear Ratio Calculations (Rockn-Roll)
Thread Starter
Melting Slicks
Joined: Dec 2000
Posts: 3,407
Likes: 2
From: Carmichael CA
Re: Spreadsheet for Gear Ratio Calculations (Tominator)
That great, any chance getting a th350 put on that SS?
Drifting
Joined: Jan 2000
Posts: 1,612
Likes: 0
From: Phoenix Arizona
Re: Spreadsheet for Gear Ratio Calculations (Rockn-Roll)
Rockn-Roll,
I have an Excel spreadsheet that I created for my Richmond six install. I will email it to you or anyone else if you want to check it out....
Bob
:cool:
I have an Excel spreadsheet that I created for my Richmond six install. I will email it to you or anyone else if you want to check it out....
Bob
:cool:
Thread Starter
Melting Slicks
Joined: Dec 2000
Posts: 3,407
Likes: 2
From: Carmichael CA
Re: Spreadsheet for Gear Ratio Calculations (Bob Turner)
I have an Excel spreadsheet that I created for my Richmond six install. I will email it to you or anyone else if you want to check it out....
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Racer
Joined: Apr 2003
Posts: 486
Likes: 0
From: Point Pleasant NJ
Re: Spreadsheet for Gear Ratio Calculations (Rockn-Roll)
Great Job While We are on it.. I thought I would just give it a face lift...
http://www.angelfire.com/droid/spook...ations-v02.xls
maybe others can add thier favorite calculations to the spreadsheet... I made a seperate worksheet for one I would like to see too...
BTW: I dont know the math for any of these... I just go by what ya tell me.. hehe
Think abouts it.. Thanks again
Spook
:reddevil
http://www.angelfire.com/droid/spook...ations-v02.xls
maybe others can add thier favorite calculations to the spreadsheet... I made a seperate worksheet for one I would like to see too...
BTW: I dont know the math for any of these... I just go by what ya tell me.. hehe
Think abouts it.. Thanks again
Spook
:reddevil
Thread Starter
Melting Slicks
Joined: Dec 2000
Posts: 3,407
Likes: 2
From: Carmichael CA
Re: Spreadsheet for Gear Ratio Calculations (Spook)
Very nice spook. The colors are awesome! :eek:
But, the Compression Ratio sheet was blank...perhaps you posted the wrong one or something...oh...wait...it's something you want me to do...I get it...OK I'll look into it. I suppose the input parameters would be bore, stroke, and combustion chamber volume. Calculated cells would be total cylinder volume at bottom dead center, and volume at top dead center, and ratio of those two (compression ratio). Should be easy to do.
[Modified by Rockn-Roll, 7:37 PM 6/5/2003]
OK DONE. I've added the new calculations. Uh, the combustion chambers are all in cubic centimeters right? Well, anyway it's here: http://67.116.80.82/Vette/Files/Gear...lculations.xls
[Modified by Rockn-Roll, 8:08 PM 6/5/2003]
But, the Compression Ratio sheet was blank...perhaps you posted the wrong one or something...oh...wait...it's something you want me to do...I get it...OK I'll look into it. I suppose the input parameters would be bore, stroke, and combustion chamber volume. Calculated cells would be total cylinder volume at bottom dead center, and volume at top dead center, and ratio of those two (compression ratio). Should be easy to do.
[Modified by Rockn-Roll, 7:37 PM 6/5/2003]
OK DONE. I've added the new calculations. Uh, the combustion chambers are all in cubic centimeters right? Well, anyway it's here: http://67.116.80.82/Vette/Files/Gear...lculations.xls
[Modified by Rockn-Roll, 8:08 PM 6/5/2003]
Racer
Joined: Apr 2003
Posts: 486
Likes: 0
From: Point Pleasant NJ
Re: Spreadsheet for Gear Ratio Calculations (Rockn-Roll)
Nah like I said ... I don't know the calcs :confused: ... I figured adding that little bit would help make yours self-explanatory (hope you dont mind).
Perhaps if I did enough research I could do one sometime... I am hoping someone else follows up with some add ons.
COME ON PEOPLE - EXCEL SPREADSHEET RESOURCE!!!!
:party:
Spook
:reddevil
Perhaps if I did enough research I could do one sometime... I am hoping someone else follows up with some add ons.
COME ON PEOPLE - EXCEL SPREADSHEET RESOURCE!!!!
:party:
Spook
:reddevil
Racer
Joined: Apr 2003
Posts: 486
Likes: 0
From: Point Pleasant NJ
Re: Spreadsheet for Gear Ratio Calculations (Spook)
True True , I got your IM... funny thing is that I was working on that calc... check it out I put both together (I get a diff when the calcs are all said and done) and gave another little upgrade to the spreadsheet. WHOOT WHOOT!
http://www.angelfire.com/droid/spook...ations-v03.xls
Spook
:reddevil
http://www.angelfire.com/droid/spook...ations-v03.xls
Spook
:reddevil
Racer
Joined: Sep 2002
Posts: 462
Likes: 1
From: York PA
Re: Spreadsheet for Gear Ratio Calculations (Rockn-Roll)
Cool spreadsheet - but I hate to type. I edited the sheet to add spinners to scroll thru various trannys by name, common rearends, and added a "RPM at speed" column just for fun.
BUT I DON"T KNOW HOW TO UPLOAD :cry
Can anybody help me out here?
Rockn-Roll > You have mail
Tominator > You have mail
[Modified by 76Frankenstein, 3:51 PM 6/6/2003]
BUT I DON"T KNOW HOW TO UPLOAD :cry
Can anybody help me out here?
Rockn-Roll > You have mail
Tominator > You have mail
[Modified by 76Frankenstein, 3:51 PM 6/6/2003]
Thread Starter
Melting Slicks
Joined: Dec 2000
Posts: 3,407
Likes: 2
From: Carmichael CA
Re: Spreadsheet for Gear Ratio Calculations (76Frankenstein)
Awesome modifications! :hurray: I'll get in there and merge them together...and of course change the credits to reflect the contributions. I hope the sheet keeps growing.
OK, I've merged all that we have so far into the workbook http://67.116.80.82/Vette/Files/Gear...lculations.xls. It's up to 30KB, but still small enough to pass around. I feel so stupid that the first calculations I did were not valid...oh...the answers were correct, but I fudged them a bit. I've double checked all the calcs and converted numeric constants for PI to the function pi(), and the conversion from cc to ci to the international standard 2.54 conversion of the respective cubed and cube root for centimeter to inch which handles better precision, and makes it more readable.
Oh, and of course I added credits for contributors.
[Modified by Rockn-Roll, 1:41 AM 6/7/2003]
OK, I've merged all that we have so far into the workbook http://67.116.80.82/Vette/Files/Gear...lculations.xls. It's up to 30KB, but still small enough to pass around. I feel so stupid that the first calculations I did were not valid...oh...the answers were correct, but I fudged them a bit. I've double checked all the calcs and converted numeric constants for PI to the function pi(), and the conversion from cc to ci to the international standard 2.54 conversion of the respective cubed and cube root for centimeter to inch which handles better precision, and makes it more readable.
Oh, and of course I added credits for contributors.
[Modified by Rockn-Roll, 1:41 AM 6/7/2003]
Racer
Joined: Apr 2003
Posts: 486
Likes: 0
From: Point Pleasant NJ
Re: Spreadsheet for Gear Ratio Calculations (Rockn-Roll)
WHOOT WHOOT... Sorry I didnt forget anyone... just on vacation.
Took a quick glimpse and am very pleased with all ya'lls work.
So... What else do we need?
I have a nice worksheet @ home dedicated to my project (expense esitmates, part #'s, actual price) That kinda thing... Don't know if we are worried about that in here.
Spook
:reddevil
Took a quick glimpse and am very pleased with all ya'lls work.
So... What else do we need?
I have a nice worksheet @ home dedicated to my project (expense esitmates, part #'s, actual price) That kinda thing... Don't know if we are worried about that in here.
Spook
:reddevil
Race Director
Joined: Mar 1999
Posts: 10,258
Likes: 1
From: Calif.
Re: Spreadsheet for Gear Ratio Calculations (Spook)
Here's a few I've collected over the years and found interesting enough that I carry them around in my PDA. There's a little bit of random data, too. Perhaps these could be added if anyone's interested? (I'd do it but I'm a Right-brain type. :lol:)
I take no responsibility for the accuracy (or otherwise) of any of these gadgets:
DISPLACEMENT
pi / 4 * bore^2 * stroke * no. cyls.
where pi/4 = .7853982
PISTON SPEED IN FPM
Stroke (in.) * RPM / 6
ROD/STROKE RATIO
Rod length / stroke in inches
(1.6 and up is "good.")
HORSEPOWER
RPM * torque / 5252
TORQUE
5252 * Horsepower / RPM
THEORETICAL STREET CARBURETOR CFM
RPM * displacement / 3456 * .85
THEORETICAL RACE CARBURETOR CFM
RPM * displacement / 3456 * 1.1
VOLUMETRIC EFFICIENCY
Actual carb. CFM / Theoretical carb. CFM * 100
MISC DATA:
Motor oil (gallon) = about 7 lb.
Motor oil (quart) = about 1.75 lb.
Gasoline (gallon) = about 6.2 lb.
Gasoline (quart ) = about 1.55 lb.
Water (gallon) = about 8.4 lb.
Water (quart) = about 2.1 lb.
EASY WAY TO CONVERT CELSIUS TO FAHRENHEIT (ballpark)
Temp C * 2 + 30
EASY WAY TO CONVERT FAHRENHEIT TO CELSIUS (ballpark)
Temp F - 30 / 2
[Modified by The Dude, 4:45 PM 6/12/2003]
I take no responsibility for the accuracy (or otherwise) of any of these gadgets:
DISPLACEMENT
pi / 4 * bore^2 * stroke * no. cyls.
where pi/4 = .7853982
PISTON SPEED IN FPM
Stroke (in.) * RPM / 6
ROD/STROKE RATIO
Rod length / stroke in inches
(1.6 and up is "good.")
HORSEPOWER
RPM * torque / 5252
TORQUE
5252 * Horsepower / RPM
THEORETICAL STREET CARBURETOR CFM
RPM * displacement / 3456 * .85
THEORETICAL RACE CARBURETOR CFM
RPM * displacement / 3456 * 1.1
VOLUMETRIC EFFICIENCY
Actual carb. CFM / Theoretical carb. CFM * 100
MISC DATA:
Motor oil (gallon) = about 7 lb.
Motor oil (quart) = about 1.75 lb.
Gasoline (gallon) = about 6.2 lb.
Gasoline (quart ) = about 1.55 lb.
Water (gallon) = about 8.4 lb.
Water (quart) = about 2.1 lb.
EASY WAY TO CONVERT CELSIUS TO FAHRENHEIT (ballpark)
Temp C * 2 + 30
EASY WAY TO CONVERT FAHRENHEIT TO CELSIUS (ballpark)
Temp F - 30 / 2
[Modified by The Dude, 4:45 PM 6/12/2003]
Racer
Joined: Sep 2002
Posts: 462
Likes: 1
From: York PA
Re: Spreadsheet for Gear Ratio Calculations (Spook)
Spook - If I kept track of the money I spent (and the wife found out), I'd never get to spend another cent ! Strictly a don't ask, don't tell policy :nono:
Pro
Joined: Jun 2003
Posts: 568
Likes: 3
Re: Spreadsheet for Gear Ratio Calculations (76Frankenstein)
http://import.h8rs.com/down8/GearRat...ations-bzj.xls
I added the calculations from The Dude on a separate worksheet. I also modified a few of the cells in the Compression Raio Calculator worksheet to add in appropriate labels (in., cc, etc.).
-bZj
I added the calculations from The Dude on a separate worksheet. I also modified a few of the cells in the Compression Raio Calculator worksheet to add in appropriate labels (in., cc, etc.).
-bZj
Melting Slicks
Joined: May 2002
Posts: 2,508
Likes: 0
From: Wisconsin
Re: Spreadsheet for Gear Ratio Calculations (Marks69BB)
Race Director
Joined: Mar 1999
Posts: 10,258
Likes: 1
From: Calif.
Re: Spreadsheet for Gear Ratio Calculations (Down8)
There's something the matter with the Street and Race carb CFM calculations in the spreadsheet. I can't see what it may be looking at the formulas, which appear to be correct.
The spreadsheet shows a 6,000 RPM 406 needing 829.2 CFM for "street" and 640.8 CFM for "race."
Doing the calculations by hand and I get:
6000 * 406 / 3456 * .85 = 599.13 (street)
6000 * 406 / 3456 * 1.1 = 775.34 (race)
EDIT: Here's the fix:
Edit the formulas to remove the second set of parens. Your formulas should now look like this:
=(A20*B20)/3456*0.85 for "street"
and
=(A24*B24)/3456*1.1 for "race."
Freaked me out for a second... :yesnod:
Very cool stuff...I'm saving every new update.
[Modified by The Dude, 12:04 AM 6/13/2003]
The spreadsheet shows a 6,000 RPM 406 needing 829.2 CFM for "street" and 640.8 CFM for "race."
Doing the calculations by hand and I get:
6000 * 406 / 3456 * .85 = 599.13 (street)
6000 * 406 / 3456 * 1.1 = 775.34 (race)
EDIT: Here's the fix:
Edit the formulas to remove the second set of parens. Your formulas should now look like this:
=(A20*B20)/3456*0.85 for "street"
and
=(A24*B24)/3456*1.1 for "race."
Freaked me out for a second... :yesnod:
Very cool stuff...I'm saving every new update.
[Modified by The Dude, 12:04 AM 6/13/2003]