Why are the rpm shooting to the red when I smash the gas on takeoff?

I like to tend to try and accelerate
really quick sometimes and it has
been not doing what I want it to do. I
used to have a truck and I could just
hold down the gas and it would just
book it and go without any problem
but when I got my mustang it won't
do like how my truck was. I could
stomp the gas on my car and the
rpms with shoot up to around 6 and
then shift and it shifts kinda hard and
then go but I would rather it not do
that. Can somebody tell me how to
fix it?