CAlexio

You won't lose your warranty, just uninstall cobb before dealership visits

ShakeNBake

I have figured out (85% confident) that I have discovered the source of my rev-hanging issues. A while back I installed an IPD Plenum/GT3TB and Cobb at the same time and started experiencing rev hanging/slight rise on high RPM downshifts at the track. I always suspected it was the GT3TB, not the tune, but I think a few folks got the impression it was the tune. I downshift while I am braking and I use engine braking effect to help xfer weight around the car early mid corner. Some folks do it all after braking, so they are not rev-matching at high rpm, and so would not experience what I've been experiencing.

I removed the IPD Plenum and TB a month ago and now have experience from two recent events (COTA and MSRC). No more rev hanging. So problem solved for me. Other things I experimented with:
- It does not happen with sport mode, which I never use.
- Tire diameter makes no difference
- Tune/No Tune makes no difference
- Tried multiple GT3TBs, no difference

So, for those of you on the fence about a tune. This particular reason not to do it is not a reason.

user1029

My friend discounted your events and took the plunge anyway. So far he hasn't ran off the cliff with the throttle getting stuck after 3000 miles