sxviper-s
Member
Wondering if there is a calculator or any way to corect my speedometer read out. I have read a few posts about cutting teeth off of the pickup gear. No rezults though as to how acurat this was.
For reference, I have an 04 viper s. I am running 8 tooth drivers and 22/35 gearing. Help with this would be greatly apreaseated
For reference, I have an 04 viper s. I am running 8 tooth drivers and 22/35 gearing. Help with this would be greatly apreaseated
BornYamaha
Member
I can tell you this. My 2003 viper reads 14% higher than reality
( radar). It shows 114mph at a real 100mph. This is with a 9 tooth original driver. If you went down to 8 tooth then 8/9 would give you a little under 89 mph if 114mph is indicated. You should be indicating about 28% higher than reality. With this gearing and the 8 tooth driver you should have a real 103mph at 8600 rpm assuming a full 1 to 1 clutch shift out . You would indicate about 132mph on the speedo. Just as a coincidence that is almost exactly the gearing you would have with a 9 tooth driver and had dropped to a 21 tooth on top in the chain case. I happen to like that gearing in mine. I have not altered my speedo pickup but I have heard it works well on this forum. If you can count how many teeth are on the pickup just divide that number by 1.28 and that will give you the amount of teeth you want to leave remaining to have a pretty close to real speed indicated.
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( radar). It shows 114mph at a real 100mph. This is with a 9 tooth original driver. If you went down to 8 tooth then 8/9 would give you a little under 89 mph if 114mph is indicated. You should be indicating about 28% higher than reality. With this gearing and the 8 tooth driver you should have a real 103mph at 8600 rpm assuming a full 1 to 1 clutch shift out . You would indicate about 132mph on the speedo. Just as a coincidence that is almost exactly the gearing you would have with a 9 tooth driver and had dropped to a 21 tooth on top in the chain case. I happen to like that gearing in mine. I have not altered my speedo pickup but I have heard it works well on this forum. If you can count how many teeth are on the pickup just divide that number by 1.28 and that will give you the amount of teeth you want to leave remaining to have a pretty close to real speed indicated.
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sxviper-s
Member
Thank you. Very helpfull. I think I will give it a try and see how it works. So there are 15 teeth on the pickup gear. So 15 divided by 1.28 = 11.71875. So clossest number would be 12 so i should remove 3 teeth in a tryangler patern and I should be close.
On my 2002 viper I ran similar gearing to you with 9 tooth drivers, slp pipes, heel clicker primary and roller secondary, and reed spacers and carbon tech reeds. That sled was faster than my current 04 viper s. Just feels like a little something is holding it back.
On my 2002 viper I ran similar gearing to you with 9 tooth drivers, slp pipes, heel clicker primary and roller secondary, and reed spacers and carbon tech reeds. That sled was faster than my current 04 viper s. Just feels like a little something is holding it back.
I have taken a tooth off for a Apex Supercharger I built and on GPS it much closer over 100 mph.