Speedometer calibration
03-21-2002, 07:29 AM
#16
Race Director
"Anyway, you said an INDICATED 80mph @ 3100rpm would really be ~75- did you mean it the other way around? B/C 3100rpm should be 81mph, or were you just giving a hypothetical example?"
Ok, I rounded to 80mph, but it really is closer to 81mph@3100rpm. That speedo & tach relationship won't change on my car no matter what tire size I'm running. It just happens that I may be going 75mph or 79mph when the gauges indicate 81mph@3100rpm. If I put on some monster-truck sized tire, I'll be going 90mph when my gauges say 81mph@3100rpm.
If you compute out the theoretical top-speed at redline on a 951 with AutoThority chips with a 6750rpm redline, top-speed is 177mph! Which would require about 400hp@6750rpm at the crank...
And I know that the picture you're talking about has been altered because I've done quite a lot of that type of work myself. So much so that I'm called on regulary to testify in court on the authenticity of documents and provide forensic analysis on people's computers to create a 'paper trail' to support various assertions (how & when various documents were made).
One easy way to verify that the picture is a hoax is to just compare the shades of black between all the gauges. You'll notice that the tach and speedo are obviously different shades (one is definitely darker than the other). My guess is that one of the gauges was taken from a different picture.
Ok, I rounded to 80mph, but it really is closer to 81mph@3100rpm. That speedo & tach relationship won't change on my car no matter what tire size I'm running. It just happens that I may be going 75mph or 79mph when the gauges indicate 81mph@3100rpm. If I put on some monster-truck sized tire, I'll be going 90mph when my gauges say 81mph@3100rpm.
If you compute out the theoretical top-speed at redline on a 951 with AutoThority chips with a 6750rpm redline, top-speed is 177mph! Which would require about 400hp@6750rpm at the crank...
And I know that the picture you're talking about has been altered because I've done quite a lot of that type of work myself. So much so that I'm called on regulary to testify in court on the authenticity of documents and provide forensic analysis on people's computers to create a 'paper trail' to support various assertions (how & when various documents were made).
One easy way to verify that the picture is a hoax is to just compare the shades of black between all the gauges. You'll notice that the tach and speedo are obviously different shades (one is definitely darker than the other). My guess is that one of the gauges was taken from a different picture.
