Just a question why would my gearbox not change gears under extreme change it's a 4speed auto ba xr6 turbo its sounds like it hits the limiter and back fires but only does this when I put my foot flat any answers would be appreciated it's going in for a service next week would like to know what I'm in for 

Car been worked at all? Auto been tuned? 

Id suggest backing off just a touch before changing in man mode on the btr... they aint a huge fan of high load changes under full throttle. 

The back fire is a worry.... id suggest compression test why its being serviced... and maybe dont thrash it till its been done.

Could be something simple or a BIG problem like fried piston or bent rod from boost spiking high in the revs which could be why the auto isnt changing under full load.

 

No expert here but go the check everything route before the problem becomes costly.

I'd say you're fairly qualified on the banana rod scenario. 

Edited 28/01/17 11:38 PM28/01/17 11:38 PM by ROB83R