Blown piston no 6 on 2JZGTE

hello,

i would like to ask if anybody knows whats the cause of my piston no 6 to be melted/ blown from the attached picture. one night i was doing a pull under WOT to 7k rpm from 3rd gear to 4th.. but once i shifted to 5th gear, smoke coming out of my tail pipe and my car have no power AFR was around 11.5: 1 boost is at 1.57BAR . i stopped and shut the engine.

upon teardown of the engine i found my piston no 6 is blown. see attached.

build spec:

Engine:-Stock 2jzgte long blockfueling system:-FIC 1220ccFIC fuel rail with 6AN single feed and 6 an return. DW 400lph fuel pumpFuellab fuel regulator93 octane fuelStock new fuel filterForced induction:-Cast manifoldTial 44mm wastegateSXE366 , 0.81ARGrimspeed manual BCtransmission:-R154OS giken TR2CD clutchEMS:-Ecumaster classic

Guessing you didn't have individual runner egts?

It is worth getting your injectors flow tested, that doesn't sound like too big an ask for a 2j motors so I would assume a faulty component.

IIRC, that cylinder does run a little warmer, but looks like it may have leaned out a little, overheated, picked up on the bore and nipped a ring that allowed the combustion gases to scoure out the side of the piston?

slides,

apparently im using a log manifold and unable to monitor the temp on every runner. but i can install the egt on the downpipe.

gord,

should i add 5% extra of fuel on that cylinder on my tuning?

appreciate the help

thanks.

As Slides said, check the injectors first - could also have been too rich (leaking) and enough loss of lubricating oil film on the bore to cause the piston to run a little hotter due to a little more friction, expand a little more, then start partially seizing in the bore.

Prior to the failure, any apparent variation in the plug colour?

It isn't an engine I'm familiar with, I'd suggest checking out the relevant web sites that specifically deal with that engine or vehicle and see if others have had similar problems, or can better advise remedies.