i have a obd0 b16 just bored it .0040 with stock compresion pistons will i need to retune
the first setup everythings the same beside the bore

b16 stock from vc to oilpan
ching chong t3o4
2.5 downpipe
440cc rc inj
2.5 ic piping
on uberdata

any help would be great thanks

 

You don't bore 4 thousandths, methinks you typo'd.

Fresh bottom ends drastically change tunes. Same car/turbo setup, down to the same head that hadn't been freshened or anything, found peak power at 24 psi vs the old tired bottom end that did it at 30 psi. Took less fuel to do it with (comparatively), but even the timing tables changed.

So... yah, you need to retune.