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Discussion Starter #1 (Edited)
So with me being sick and tired of "oh what's my top speed?" and "what will swapping to this differential do to my speed?". I put together a spreadsheet on Excel that you can download off my skydrive (more than likely permanent) and by tweaking things on the table you can see how your gears will change. Using this table will allow you to;
- See actively what changes to expect with different tires.
- Preview differential swaps.
- Adjust shifting habits safely for higher RPM governors.
- Know in advance when taller gears start becoming an issue for your build.

There are notes abound on the spread sheet itself, READ THEM!

Before you start messing about with it, save a copy of the original just incase
you f*ck it up.

Everything that is suppose to adjust based on a specific change, will do so automatically without you changing the whole thing.

If there is something missing from the spread sheet you'd like to see or just something you'd like added, leave a comment and I'll get to it when I can.

Genesis Coupe Gear Speeds and Ratios.xlsx

Created with MS Excel 2003, older versions will need an update, newer versions or modern versions of OpenOffice will have no issues with it.

*edit
v1.0 - initial release.
v1.1 - added overall diameter calculator under "Tire Size Calculator" header.
v1.2 - added M6VR2 with 3.737 gear ratio.





 

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Jedi Master
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nvmd i got it... very nice
 

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White 2.0T A/T
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very nice snoopy like always. This should get stickied
 

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What the what?
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Everything is awesome! But one thing would make it perfect:

Being able to account for different tire and wheel diameters. The rear stock 19s diameter is a touch bigger than the front, but the difference is negligible... Also, it would help those who are running much wider tires and bigger wheels, as well. Just a thought.

Edit- Excuse me, I meant circumference, not diameter.
 

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Discussion Starter #10
Everything is awesome! But one thing would make it perfect:

Being able to account for different tire and wheel diameters. The rear stock 19s diameter is a touch bigger than the front, but the difference is negligible... Also, it would help those who are running much wider tires and bigger wheels, as well. Just a thought.

Edit- Excuse me, I meant circumference, not diameter.
You can.
If you look under the the "Top Speed Tables" and "RPM Tables" headers you'll see a yellow square that says "Tire Size***", beside that, a blue square that says "26.68", change the spec in that blue square and it'll adjust the table for the new tire size. The OE sizes that I referenced are based on the rear tire for both 18" and 19" OE Bridgestone Potenza's. When you're shopping for tires you'll see the circumference for your particular size and just type that into the square to adjust your tables correctly.

In white across from the variable square under "Top Speed Tables" I wrote the OE tire circumference for quick reference. Anything under a yellow square "Final Drive", "Tire Size", "RPM" and "Gear Ratio" are adjustable to modify the tables. In case people forget what the OE ratio or whatever is, I marked the original final drive ratios in gray squares under "FD-Original", that way you can simply refer back to them.
 

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What the what?
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You can.
If you look under the the "Top Speed Tables" and "RPM Tables" headers you'll see a yellow square that says "Tire Size***", beside that, a blue square that says "26.68", change the spec in that blue square and it'll adjust the table for the new tire size. The OE sizes that I referenced are based on the rear tire for both 18" and 19" OE Bridgestone Potenza's. When you're shopping for tires you'll see the circumference for your particular size and just type that into the square to adjust your tables correctly.

In white across from the variable square under "Top Speed Tables" I wrote the OE tire circumference for quick reference. Anything under a yellow square "Final Drive", "Tire Size", "RPM" and "Gear Ratio" are adjustable to modify the tables. In case people forget what the OE ratio or whatever is, I marked the original final drive ratios in gray squares under "FD-Original", that way you can simply refer back to them.
I see, in my mind I was thinking that most people are too lazy to calculate their circumference based on the tire specs. I never realized that sites do show that spec. You have thought of everything. I wish there were more people like you local to me that I could learn tons from, but Gencoupe will have to do.
 

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Discussion Starter #12
If you ever need to, you can get a guesstimate of the overall diameter by this simple equation;

Practice sample: 245/45r18
((((Width*(Aspect/100))*2)/25.4)+Rim Diameter) = Overall Diameter
((((245*(45/100))*2)/25.4)+18) = 26.68110236

or 26.68

This is just a rough, variations by manufacturer will occur so use their exact numbers if you want higher precision.

I'll update the calculator with the tire size calculator in a little bit, find it on the bottom of the sheet under it's own heading.
 

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Discussion Starter #13
ok, added the calculator table to the bottom of it, same link new version. Must admit this new SkyDrive is pretty handy now. It's nice that I can just update on the fly now and not have to keep uploading new versions.

also added an auto tire differential notifier beneath that, go over 103% or under 97% and you might run into tire size issues with the TCS and speedo.
 

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i are you sure about the differential ratio
i have a 2.0 r spec if i check rpm versus speed i'm closer to 3.727 that 3.538
but will do some other logging and check before confirming
 

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Discussion Starter #15
diff ratio is spec'd by Hyundai, speedo can be off by as much as 10% as per NHSTA guidelines.

You can verify your own differential by looking at the while label on the bottom of it on the aluminium cover plate.
 

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Jedi Master
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diff ratio is spec'd by Hyundai, speedo can be off by as much as 10% as per NHSTA guidelines.

You can verify your own differential by looking at the while label on the bottom of it on the aluminium cover plate.
this has been confirmed by both me and redrasbery (excuse spelling) we both logged the ecu mph and compared to speedometer and found, 25-50mph it was off by 3-4mph off, the speedometer read faster so 50speedometer was 46mph ecu. and when you get to the high mph range, 70-90mph, it's off by 4-5mph.

Now is the ecu correct or is the speedometer correct?, who knows without have a reliable 3rd party measuring device. i'm more likely to believe the ECU though. meaning... if i add large tire diameter by 1 inch it be 100%
 

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this has been confirmed by both me and redrasbery (excuse spelling) we both logged the ecu mph and compared to speedometer and found, 25-50mph it was off by 3-4mph off, the speedometer read faster so 50speedometer was 46mph ecu. and when you get to the high mph range, 70-90mph, it's off by 4-5mph.

Now is the ecu correct or is the speedometer correct?, who knows without have a reliable 3rd party measuring device. i'm more likely to believe the ECU though. meaning... if i add large tire diameter by 1 inch it be 100%
i normally checked obd km/h versus gps km/h and they are spot on
but haven't confirm with the speedometer

some car have higher speedometer value than obd value probaly to prevent some lawsuit from ticket .. i drove a VW one time and that value was near the 10%
 

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Discussion Starter #19
My GPS and my OBD are spot on as well, my cluster is faster in the lower speeds but slower at higher. I've adjusted my needle several times, no change so what I did was set my cruise control at 110 kph, matched my needle and then closed it all up. I've done a few colour conversions now and calibrated a few clusters, everyone else's goes fine, so I'm thinking it's my stepper motor.
 

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I'd rather do it myself
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i normally checked obd km/h versus gps km/h and they are spot on
but haven't confirm with the speedometer

some car have higher speedometer value than obd value probaly to prevent some lawsuit from ticket .. i drove a VW one time and that value was near the 10%
I trust my Garmin's mileage calculations 100%. With my last tire change the speedo below 50 mph is dead on with Garmin. It tends to stray slower above that but not by much. Odometer and ECU mph is off by over 5% slow. This is good for the odometer miles racked up but you need to keep it in mind when doing maintenance or fuel mileage calculations.

The onboard mpg estimation were always high by 2-4 mpg. Now it's down to 1-2 mpg high.
 
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