I have never personally done this particular mod but I pretty much figure the way to tune for it would be to first figure for your correction factor. Take that 200mph number and divide it by your current max speedo number (will vary with the car) which will net you the correction factor. Then go into the tire_revs_per_mile in the tune and multiply it by your correction factor. That should get it. Verify with a GPS or a buddies car running next to you. Good luck.
I currently have a 160mph speedo = correction factor of 0.8; I hate to have to install it and play around with it to get it to work. I guess we'll give it a try. Thanks
I remember reading something MileHiDyno said to use the gear table in the Predator to recalibrate the speedo. I don't have a Predator I have the Xcal2
Your correction factor/multiplier should be 1.25......200/160= 1.25. Sorry if I didn't word my last post too well. If you use the .8 like you want (160/200= 0.8) then it will become the divisor rather than the multiplier. Hope that explains it.
My tire_revs_per_mile is 806 so 806 X 1.25 = 1007.5 That's a BIG tire!
You can PM Hissman on this topic. He has a thread or a reply somewhere in the Terminator Talk section regarding the 200MPH overlay from Speedhut.
He verified the accuracy of his with some type of GPS device from the Military. While it isn't quite EXACT, he has it dialed in close enough ;P.
At any rate, let us know what you end up using to calibrate yours :beer:
Actually if you were to take that 1007.5 figure at face value that would be one SMALL tire. Now obviously for your purpose you will not look at this number in a literal fashion anymore because it is scaled from your correction factor.