Sintari

Alright so I am going to be tearing apart my 2JZGE, boring it out 0.20 over and putting in some lower compression 2JZGTE pistons. Im using the same rods and crank.

Now I read in other threads people have done this with no problem. Just wondering if anyone had any issues with anything else? I was on IRC and chatting with a guy who had a similar setup and he said his car ran like **** because the compression was too low. Now 8.5:1 is standard for the 2JZGTE, correct me if I am wrong? And the NA is 9:1. Why would lowering the compression in the NA motor cause his car to run sluggish?

Did he just not know what he was talking about or was it something else causing this to happen? Im curious if just lowering the compression on the NA motor would cause this to happen. If it will, then Ill buy forged, high compression pistons and call it a day.

Any advice would be helpful.

SUPRMSC

iTrader: (7)

First, the stock NA compression is 10:1. Second, You cant bore the block and use GTE pistons, you have to use appropriately sized aftermarket pistons. Now maybe possible to stroke it with GTE pistons, but then you might have clearance problems with the valves.

Lowering the compression is fine on the NA's many do it via thicker headgasket. It is not necessary to bore anythng or use pistons.

kbprice

Are you planning on going turbo soon? Otherwise lowering the compression will do nothing but lower peak power output. What year car is the engine from? I'm asking because the 98+ VVT-i engines had weaker connecting rods and if you are going to have everything apart anyway why not replace them wiht some aftermarket rods while it's apart, Eagle Rods are only like $450 on Ebay and are decent.
If you are planning on staying NA get some high compression pistons. JE makes 10.5:1 pistons would be great if staying NA. Have the head ported and polished, 1mm oversized valves, Crower springs and retainers, header, port match intake and exhaust manifolds. Maybe a longer duration cam as well.
I wouldn't recommend lowering your compression unless you have turbo plans though.

itsme4g63

wow, I thought th eonly difference between the turbo and non turbo 2jz motor is the head, apparently I was misinformed.

SUPRMSC

iTrader: (7)

The major differences are in the head. But the GTE and GE blocks differ by a set of oil squirters and piston groves. Thats it.