If it was your money and pistons..

[Tombola]

while tuning my gsx1100f turbo setup, it made 177hp, but unfortunately it's started losing compression on two of the cylinders caused by the rings.

Im now left with having to tear it down, question is if it was your money what would you do while you was there? New rings? Or change pistons and rings? 

Is there much to gain by polishing and smoothing the ports?

[Gixer1460]

What pistons? If OEM, the rings aren't best placed for a turbo so a new set of rings would likely go the same way.

For aftermarket - i'd slump for MTC in a turbo all day long. Mild grind and smooth to inlet won't harm whilst a good polish in the exhaust sometimes pays dividends.

[MeanBean49]

If your running stock pistonsi would be willing to bet the rings are fine, more likely is the ring lands on the piston have colapsed. Best easy fiix is get a set of gen1 busa pistons and rebore.  Good for a reliable 12psi then

[Tombola]

Ahh! That's what he said I spoke to him on the phone, and was busy at the time. Makes sense now.

What do I need to do in terms of compression ratio, searching on the web some have fitted decom plates? 

[Swirl]

Interested on the outcome of this

[MeanBean49]

Just swapping to busa pistons drops tge compression, its about ideal for turbo use.

Only need spacer plate if you use the busa rods as well

[vizman]

if i had money or indeed someone else's' money, i'd go mtc....

....but the busa pistons hold up well and are cheap(ish) like the bungie cord around my pants.

[clivegto]

Same thing happened to me with standard pistons, blew them apart between the rings. I fitted busa mk1 pistons to solve the problem.

[Tombola]

What MTC pistons do you fit? For a hayabusa? Or gsxr1100? 

[CossiEst]

http://www.Eblag.com/itm/Suzuki-GSF1200-Bandit-MTC-1216-Turbo-Pistons-81mm-/252015586383

[bruteforce]

Whatever piston route you go, make sure you MEASURE the new CR. Despite what everyone says the various F/R motors are not identical. For turbo road use I go for 9:1 CR.

[Gixer1460]

On 9/2/2017 at 8:41 AM, CossiEst said:

http://www.Eblag.com/itm/Suzuki-GSF1200-Bandit-MTC-1216-Turbo-Pistons-81mm-/252015586383

Pisses me off when sellers can't be arsed to show a correct product picture - those are clearly NOT turbo pistons! And this may have changed but MTC's used to be only available @ 80mm, as this was the entry level 1327cc kit piston and 10:1 CR is a bit tall IMO if you want to run decent boost -  and who doesn't!