problem Help?

[my08350z]

okay so i just installed testpipes and decided to see what they do and see if naything different to my car like performance..i noticed a huge gain but now if i floor it in 1st to 2nd around 3000 rpm5500rpm the car lags and loses traction and i just slide in 1st and 2nd and if i redline and shift now my back tires go flying... and i could probly spin out anyone no why? or how i can fix it..

maybe new tires???i dont have traction control i own a base Z

[evildky]

the testpipe isn't the reason, a testpipe adds maybe 5 hp

base models came with an open diff, the sliding and spinnig si because only 1 wheel si turning, get a lsd and you will ahvepower at 2 wheels instead of 1 and will be less likely to spin