Need help with this ??
 

I recently Purchased and installed AAM Short tails, and when i press gas somewhere between 2.5k-3k rpm just shoots up to 6k-6.5k rpm. what is causing this. short tails is the only thing done to the car so far. its 7A/t transmission. what can be done to fix this, i have read that Tune might fix this but i have no clue where to start at. any suggestions will be really helpful thank you everyone. :confused:

Hmm, never heard of this happening. Can you post a video of your Z doing this? Does this happen in auto mode, manual mode, or both? Does it happen at WOT only, or regardless of the amount of throttle you give it?

Are you experiencing this when its in Auto mode?

You shouldn't have any issues seeing its NEW 2015.

Make an appointment at your local dealer so they can look into it.

i will take video tonight on my way back home and post it up soon. thank you. its a automatic transmission. it happens when i am accelerating at higher speed the rpm just spikes up high then drops back down all sudden. didn't have the issue with my stock catback. so i am questioned

Right, we understand it's an automatic transmission, but does it happen in auto mode (transmission shifts automatically) or in manual mode (you do the shifting manually, after having moved the shifter in to the position on the left), or both?

Either way, I'm with Trips; if this is a new 2015, take it to the dealer and let them sort it out. That noted, still post up a video when you can.