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Better than Drugs!
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Get an SCT tuner- that will do it
 

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Too Soon, Junior!
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No, SCT and DiabloSport and similar companies pay big money to crack the ECU programming in the vehicles that their tuners are designed for. You can't calibrate your speedo with a simple OBDII reader.
 

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Discussion Starter #7
Is it possible to buy an OBD tuner, have my custom tune uploaded and fix the speedo, and then sell the tuner? Will I need the tuner later on for anything other than uploading a new tune?
 

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If you don't want to spend the money you can record your speed at a certain RPM in a certain gear and then look up to find out what the difference is between the different gears. Take the needle off and reset it. An aftermarket gear is only going to make it off by a certain amount of MPH.
 

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Too Soon, Junior!
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Is it possible to buy an OBD tuner, have my custom tune uploaded and fix the speedo, and then sell the tuner? Will I need the tuner later on for anything other than uploading a new tune?
Nope, the tuner "marries" itself to the car


If you don't want to spend the money you can record your speed at a certain RPM in a certain gear and then look up to find out what the difference is between the different gears. Take the needle off and reset it. An aftermarket gear is only going to make it off by a certain amount of MPH.
I'm not sure this would work too well lol, all of the instrument cluster needles are pressure loaded against the stop pin.
 

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Obviously you meant this figuratively...but is it actually impossible to use a tuner with another car once it as been used with mine?
Any changes you make to your car with the tuner will vin lock itself to your car.
To use it with another car you need to undo the changes and put it back to stock.
 

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Too Soon, Junior!
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Yes it's impossible unless you revert all of the settings on your car back to stock, or if you're an expert in reverse engineering software.
 

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If you don't want to spend the money you can record your speed at a certain RPM in a certain gear and then look up to find out what the difference is between the different gears. Take the needle off and reset it. An aftermarket gear is only going to make it off by a certain amount of MPH.
Their is now way this would work. An uncorrected speedometer doesn't rear a set speed over what you're really going. The gap gets bigger as you go faster. At 40 it may read 50, but at 70 it would read closer to 90 or so. Rough ballpark numbers based on 4.10s. So just moving the needle down 5 MPH may fix it at 25, but will still be incorrect.

This formula will give you your speed. X=(3.27/4.10)Y
Let Y equal your speedometer reading and solve for X. This will give you your actual speed. This is assuming 4.10 gears. If you have different gears, just substitute your gear ration in for 4.10.
 
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