If your running forged pistons then I would say no they aren't necessary. If you do remove them and block off the hole your oil pressure will be higher so you would have to port the OFH.
Advantage - possibly more oil available for engine internals.
Disadvantage - You may end up with too high oil pressure and feed too much to the turbo blowing the seals.
stock pistons - No oil for cooling the piston raising the temperature of the piston and causing damage.

I have forged pistons (6 bolt) and still put the oil squirters back in. If I was running a 7 bolt I probably would delete them due to the inconsistent opening pressures (from Magnus testing). They tested them and some would open at a fairly low pressure such as what you would see at idle. Basically it would act as a leak before the main bearings. Low main bearing oil pressure = toasty bearing IMO.

Your 6 bolt so just make sure they function fine or buy brand new oem squirters and call it a day.

 

Hmm interesting, so for the stock pistons they are there just for cooling purposes? I like the idea of more oil getting around.

 

I strongly believe in the advantages of oil squirters. They keep the pistons cool and that reduces detonation.

Also as an option 6 Bolt oil squirters are compatible with 4g63 Evo motors.

***Note*** The evo squirters only work as a direct swap for the 6 bolt motors. Never a 7 bolt.

 

The evo squirters are they an upgrade or do both have the same potential?

 

I dont know if they perform better but I hear they have alittle better flow but I cannot confirm that since I dont use them myself or have seen anyone personally use it.

 

Nice I'll have to somehow compare the two one day and post the results

 

Great Idea! I feel like thats easier said then done though lol. Any idea on how you could measure the flow rate to compare the both?

 

I just wonder how much better can oil suirters get redesigned. If its a tiny bit bigger I could see the advatages to that already! Way less chance of it getting blocked up by dirt.

Looks like theres only small differences that dont make it any better unless you really need clearence. Here's a sweet link on it!

http://www.dsmtuners.com/forums/newbie-forum/422141-evo-8-piston-oil-squirter-question.html

 

This seems to be looking up to have a lot of potential. The idea of having better oil flow throughout the motor is great.