Keep in mind cast pistons aren’t necessarily weak to ANY boost, when boost is in the mix knock (pre detonation) is what mainly kills pistons, not boost and cylinder pressure alone. If you were to decide to use the cast na pistons they’d probably live a good life if you were to tune on e85 and your tune is in proper order, that’s a big one on boosted applications. I don’t have a lot of hands on with the turbocharged Lima 2.3, however my race car is powered by a Mitsubishi 4 cylinder, and while comparing a 4g63 and a Lima 2.3 is comparing apples to oranges, in the Mitsu world we’re going pretty far with cast pistons. Even in the factory turbocharged variant of the 4g63 the stock pistons were cast with a 7.8:1 (8.1:1 95-99) compression ratio, and with a huge following many guys have seen over 500 at the wheels on stock internals for stretches of time. We put my good buddy’s car on a heartbreaker Mustang dyno on a stock block (earlier 7.8:1 pistons) with a Holset hx40 turbo with a standard sized 60mm compressor wheel in a .70ar open t3 turbine housing from bullseye power and made 547 at all 4 wheels on 24psi on e85. This was in 2018 and that engine is still taking a beating, since having the car on the dyno it’s been up to 30psi on the hx40 and this off season we switched it up to a Chinese ball bearing gtx3584rs clone (67mm compressor) with a .82ar open t3 housing so I’d be willing to guess we’ll see over 600 at the wheels without turning it to the moon as the same turbo has yielded mid 700s on the 4g63 on low reading dynos cranked up. My other buddy Erik currently holds the “stock bottom end” record for the Mitsubishi 4g63, car made 767 at the wheels through an automatic trans last time it was on the dyno with a stock bottom end that he had for 12 years in 5 different dsm’s and over 230k miles on it, that bottom end went 9.0 at 150 on the poor 230k mile stock pistons, that block finally got hurt so in went a “fresher” stock bottom end with 150k’ish on it, after not being in the car almost a year he ran his personal best resetting his own record right off the trailer with 8.90 at 151 in the quarter mile. My own personal car I threw boost at a stock bottom end 4g63 that was originally a non turbo bottom end with 9.0:1 compression pistons with a thinner/weaker ring land and out of those 4 seasons seeing boost 3 of them were over 400 to the wheels on e85. Last time my car was on the dyno I made 454 at the wheels at 22psi on 93 octane pump gas with a Borg Warner s363sxe turbo in a .82ar open t3 housing with every intention to go back and crack 600 on the non turbo bottom end with 130k miles with e85. Unfortunately a week after I got off the dyno and was supposed to go back soon I did a 40 roll with my buddy’s wife’s 3v 4.6 mustang on a 150 shot of Cosby juice during a “Mexican vacation” and the seal on the fancy expensive k&n oil filter I was using (usually used oem denso or Wix) decided to let loose and starved it of oil mid rip. Wiped out a few balance shaft bearings and the oil pump, but the 130k mile non turbo pistons looked fantastic when I tore it down even after all that abuse, ring lands looked great.
Long winded story I know and again comparing apples to oranges, but the moral is forged pistons aren’t everything. Of course in the Mitsubishi world there’s plenty of folks making big power using aftermarket forged pistons and h beam rods or better, but also a good handful of us that have pushed the stock cast pistons and stock rods to some pretty fascinating numbers and times (not so many with the non turbo pistons like myself but that’s a different conversation). Along with the condition of everything and proper assembly, tune and fuel selection play the biggest part in boosted applications. If your tune is junk and you see a lot of knock, it won’t live long, and if you’re limited on fuel to 93 octane or less then you’re real limited on how far you can go without avoiding knock becoming an issue and keeping air charge temperature down. I’m not saying throw 500 horsepower at cast na Ranger pistons, but with a proper tune and e85 or 110 octane race gas I’d bet the cast 2.3 pistons would live a pretty happy life at 300ish. Take that as you will.
Welcome Visitor! Please take a few seconds and 
