how much boost is safe with "NA pistons"

[zomesi]

hi everyone

firat of all,sorry for my English.
second of all yes i searched a lot about my question in dsmtalk.

my question is" how much boost is safe with intercooler and with "NA pistons"?"
(without water injection)

and also please give your ideas about lowering compression by editing the combustion camber or a thik head gasket..


i know the piston differences...upper ring lands...and higher compression..


the engine is 1g block(91) with a 2g head and is going to rebuild.

all people are thinking about more boost than stock but my goals is about 6-8 psi boost and 200-220 hp on flywheel.

and its going to be tuned with megasquirt.with out knock sesning(ears are better i think)

thanks all

 

[wolf alchemy]

I'm not sure on the answer to your question, but definitely do not rely on your ears to find out if you have knock or not. It's there for more than just sensing knock. It also tells the ECU to retard the timing to prevent damage in case of knock. Furthermore unless you are a bat with supersonic hearing. There's no way you will hear knock over the engine or exhaust. Unless of course it's a catastrophic knock that blows the engine.

 

[lasershark]

the engine is 1g block(91) with a 2g head and is going to rebuild.

Why not find some cheap used oem pistons and call it good, if you are rebuilding anyways...

 

[zomesi]

I'm not sure on the answer to your question, but definitely do not rely on your ears to find out if you have knock or not. It's there for more than just sensing knock. It also tells the ECU to retard the timing to prevent damage in case of knock. Furthermore unless you are a bat with supersonic hearing. There's no way you will hear knock over the engine or exhaust. Unless of course it's a catastrophic knock that blows the engine.

thanks for the info..

Why not find some cheap used oem pistons and call it good, if you are rebuilding anyways...

really not available...

 

[Kryndon]

6-8 psi is more than safe for a stock turbo system with N/A pistons on the 4G63. Because you have the 1G 6 bolt block, that means you'll have the stronger rods, and I believe the N/A pistons were 9:1 compression, so even safer. Definitely get a 1G knock sensor though, a used one should be no more than 20-30 bucks. Keep the oil squirters in the block. Your result may be just shy of 200 HP at the crank, but you can up the boost a little more (up to 11 psi) if you think it's running fine with little to no knock.

I'm only speaking from experience as that's my current setup.