455GTO

iTrader: (18)

So while tuning my car with HP Tuners we noticed that the tach reads 500rpm less than what HP Tuners reads at redline. We have the limiter set at 6800rpm on the computer, but it hits at about 6200rpm or so on the tach. Is this normal for the stock tach to be that far off?

I recently went to the track and had a subpar trap speed of 111.7 on my full bolt-on Torquer V2 cam Trans AM. Wondering if I could possibly be short shifting and HP Tuners is off?

sreve

iTrader: (3)

Quote: Wondering if I could possibly be short shifting and HP Tuners is off?

I really doubt it. The factory tach is far from a precision instrument and will not react
quick enough for a very fast rpm rate change. HPT logs many frames a second depending on how many pids you log at a time, but will still react much faster than the factory tach.

HCI2000SS

iTrader: (2)

Mine seems to be about 300-400 rpm off as well compared to the dyno that I was on