i have an '01 lightning with 15,000 miles, pretty much stock except a boost bypass installed. i've noticed what sounds like a slight valve knock in a hard 1-2 shift at WOT. anyone else noticed this? could it be valve knock from the boost between shifts or, is this something else?

 

I believe it's called Torque Reduction..?
Baiscally some cylinders are not fired during the 1-2 shift to lessen the shock to the drivetrain... To me it kinda sounds like a metallic fart. This seem on par with what you are experiencing?

 

What he said.

A chip or reflash will "cure" that sound. Some say keep the torque reduction, some remove it via reprogramming.

I got rid of it. It's more of an annoyance to me.

 

Well it shouldnt sound like Valve knock though. Torque reduction sounds like a fart coming out of your exhaust. Like a pffffffffff noise. Its an odd sound and if you didnt know what it is you may think something is wrong so it may be it

 

thanks, that sounds about right. i've been thinkink about a power package from rpm outlet which would have a new chip and should take care of it right? or should i try to get rid of this issue?

 

You can specify in your tune on your chip if you want to get rid of torque reduction or not. You can also chose to just reduce the torque reduction rather then eliminate it.