Quote: Originally posted by Mitchy on 05 November 2003
What tilt setting are you using???
I detest these things, i had 1 for a week and quickly got rid. Just a waste of money IMO.
Its far more accurate and consistent than a stopwatch and proved invaluable for comparing modifications. If youre just dump it on the dashboard like a numpty and dont bother finding a way to calibrate it, then of course itll give you crap times.
I took mine down the strip a few times at York, and on tilt setting 0.005 the AP22 consistantly over read by between 0.1 and 0.2 seconds over a 1/4 mile. Thats not too bad in my opinion. Enough to give you an idea of the cars performance.
For years most magazines tested using a "5th wheel" on the road which tended to skip off the road at high speed giving conservative readings, but most people take magazine stats as gospel...0.2 seconds out over a 1/4 mile seems good in comparison.
The main problem with the AP22 is that you need a totally flat and bump free piece of road to use it on. I think a lot of people who buy them dont understand how they work. Ive read a lot of "I timed it with an AP22 and got a great time even though i was going up hill". Going up hill causes the unit to tilt back, fooling the unit into thinking youve accelerated more. vice versa for downhill.
I only ever used 2 carefully selected pieces of road for my runs, the one where I could reach 100mph was miles away, so usually used a shorter piece of flat road where I could only reach 70 before needing to break.
I wouldnt recommend taking AP22 results as gospel because of the various factors that can effect the read outs, but its not difficult to get it accurate enough to be useful.
If you dont like the time just fiddle with the tilt setting and heah bobs your uncle.
But if youre the sort of person that does that, then why not just save your money and pretend you have an AP22 and make up a time?