I'm ordering my vitaras this week. My engine is a turbo JDM D15B. Is 75mm the correst size piston?

 

Any of them will work. 75mm will be tad loose in the cylender, which is fine. It'll be a bit noisy and sound like a diesel until its warm and then it'll quiet down some.

 

Will the pistons be able to handle lots of boost still? By lots I mean around 18psi with an evo III 16g
and i'm guessing 75.5 are too big?

 

with 75mm your gonna get some piston slap when the engines cold, if you want to do it right get 75.50mm vitaras and have a machine shop bore the cylinders out to the proper specs and that way you will have proper piston to wall clearence and you wont have piston slap when the engines cold. If you are really set on 75mm vitaras make sure your cylinder walls are egg shaped and out of round

 

Egg shaped? I'm not doing the install myself. So your telling me either way I need to get someone to bore my cylinder or make it egg shaped? I think I might sound like an idiot saying I need my cylinder egg shaped to a shop on the phone. If I got the 75.5mm would the shop know how much to bore it or would I need to find out and tell them?
Maybe I don't want vitaras then. Is there any piston that will fit JDM D15B?

EDIT: I forgot to ask is piston slap bad? Will anything get damaged?

 

lol you "dont" want your cylinders out of round(egg shaped). Unless your cylinders are brand new and have zero miles on them i wouldn't get the 75mm vitaras. If you get the 75.50mm vitaras and tell the machine shop they are 75.50mm overbored pistons they can bore out your cylinders no problem and get you the proper piston to wall clearence. Its just proper engine building

 

I don't know of any machine shops in my city. I guess i'll try and locate one, do you know approximately how much a shop will charge to bore out the cylinders to 75.5?

 

i know my machine shop hear charges like $10-$15 bucks per cylinder

 

Thatas amzing I was expecting a few hundred for the work. I bet it will be expensive to find someone to take the block out to get it ported. I'm gonna call around thanks.

 

I asked the company selling the pistons andthey told me
"well.They tend to be a lil bit loose but they expand when the engine warms up. I ran these pistons on my engne for over 2 year with what they call "Piston slap"(which i dont think it is) and my engine was healthy. I drove my car 24/7 and never had a problem with it.

The sound they call "slap" in my opinion and my mechanics opinion is due to the floating wrist pin which runs more loose than pressed fit piston. Even Wisecos/Arias/SRP/CP forged pistons do the same sound."