Racing against me

[Rocket 99GT]

I went to a big empty parking lot and I was trying to see how long will it take from 0 to 60. I couldn't check the time because when I let rip the car was pulling to the right and I kept fighting with the steering wheel to keep the car strait (is this normal?).
I asked my mechanic about this, he said that I was running the RPM to high (which is true as I would change gears only when the niddle was about to touch the red). He said that the car also did that because the tires were spinning to much and he adviced me no to make the tires spin so much and not to RPM the car so high.
Do you think that what the mechanic is saying is true or could it be that there is something wrong with the car for pulling to the right as such speed.

............................................99GT…r ear sway bar (adjustable), rear lower control arm, traction bars, tokiko struts illumina 5 position, tokiko shocks, strut tower brace, caster camber plates, racing lower springs, 3:73, underdrive pulleys. NOW I WILL ADD POWER.