The 6 speed automatic G8 GT hits 105mph in the 1/4 mile. But to go above that, there will have to be a shift. 3rd Gear @ 6000 rpm = 105 mph. I hope there is a better way to finish the 1/4 mile than by shifting...

Hopefully someone smarter than me has figured out the programming on the transmission computer, because I sure could use a more positive shift... perhaps that would put you in to 4th before you cross the line.

It is interesting the way that GM maximized the 1/4 mile in three gears. I wonder if you were pulling hard in 4th if you could have achieved a better time, using a lower gear ratio overall. It certainly would have been better to be higher in the rpm range, than just starting 4th gear....

Just my 2 cents.

__________________
New 2008 G8 GT Liquid Red / Red Inserts
former 2006 Dodge Charger Daytona "GoMango"
"Don't tell me what it will do, show me..."

Did you run it at Sealy of Baytown?

Get a tune and have then change the rev limiter and shift points. Or, if that is out of the cards, shift it yourself using manual mode and the computer won't pull the gear.

^exactly what i was about to say...

Unless you have a massive increase in power you will arrive at the finish line shifting gears, or so low in 4th gear that accelleration will be on the low end of the power band. If you put a little higher gear in the rear end you could solve this problem, but it may create others.

In my last car I went from a 245-55/18 to 245-50/18 tire and it was almost an inch shorter (.94"). I had to re-calibrate my speedometer, but the resulting change in overall drive ratio decreased my 0 to 60 time from 5.7 to 5.4 seconds. With the shorter tires the wheels had to turn more revolutions to go the same distance. I wonder if something like that would work here. Although I am not changing out brand new rubber....

__________________
New 2008 G8 GT Liquid Red / Red Inserts
former 2006 Dodge Charger Daytona "GoMango"
"Don't tell me what it will do, show me..."

Taller tires would be the easiest way.

If you want to be in 4th gear then get LOWER (Higher #) gears in the rear. stock is 2.92, I'm going for at least 3.55 or 3.73. you will decrease your 60ft time and you will be in 4th on the top end. to figure your rpm, just look under WOT how much your RPM drops Between 3rd and 4th. you should drop 1000-1500rpm you should still be well in the power band.