he lately i've notice when i'm doing anything around 60 or more and i let off the gas my truck almost feels like i'm brakeing and it sounds like a big rigs jake brake. if i give it just alittle throttle down hill it don't do it. but if i let off all the way, you can feel it start to slow down. now if i tap the brake so the tcc unlocks it fine because the trans is not "locked" to the motor. what give?? can there be too much backpressure from my turbo causeing it to slow the motor like a jake brake would? turbine is a t4 .84 a/r

 

The tq converter should unlock when you let completely off the gas.

 

I was thinking something to with the tranny also, not the turbo.

 

Your going into DFCO most likely. The injectors stop firing completely and your get more engine breaking. Taping the brake pedal at any speed will unlock the TCC. That's what your feeling as it disconnect the motor from the tranny.

 

under a certain speed yes it will unlock but not above 60ish.

 

i understand that tpping the brake unlock the tcc. but i have the tcc set up to stay locked because of the cruise control tcc thing.

so its not the turbo causing more eng brakeing? i guess i'll just have to set it back up where the tcc unlock at 0% throttle at any speed. but with my detroit locker and the tcc going from unlock to lock with the touch of the pedal makes for an anoyying ride with the big clunk. hmmm i guess i have to pick one. (jake brake or clunk)

 

Mine does it too. The "jake brake" feeling that you get is DFCO, and for whatever reason engine braking with a turbo sounds like a big rig. Mine is incredibly loud above about 3000 RPM.

 

i think i'l leave it that way since i know what it is. i think it sounds cool. now i just need a air horn and i'll be all set

you know now tht i think of it i think i may have made my dfco alittle more agressive when i did my injectors. maybe thats why it come in so strong.

 

Mine unlocks at any speed if I let completely of the throttle.

 

Sounds like DFCO to me as well as my truck does the same thing.