What is the most boost i should run on a stock rb20? i searched google and came up with either 10 or 12 psi. who has run 10 or 12 and how much of a difference was it and how reliable will it be?

 

10PSI is stock so it should be very reliable

12PSI is where I would sit with the stock turbo unless you want to throw the turbine wheel ouot t he muffler & possibly suck chunks of ceramic back into your cylinders.

This is no urban myth, it DOES suck chunks back inside and shred your cylinder walls. It may not happen for a while, but I guarantee you, at some time, that around 14PSI your wheel will come off & shatter.

 

when i searched on google it said that the stock psi was 8lbs. so the stock is 10?

 

From my experience the Rb20 boosts stock at 10PSI

 

ok, thank you for the info,this is why i check the forums after i get info from google. when i upgrade the turbo what is a safe boost amount?

 

That is a complicated question that depends on piping size, turbo size, turbo CFM at different pressures, injector size and your ability to alter the fuel/ignition maps.

PSI isnt a ameasure of the quantity of air in your intake tract. PSI is a RESULT of the quantity, not the measure. You need to figure out your power goals, decide on some injectors to reach your goal, an ECU that will allow you to run those injectors and THEN choose a turbo that will push the CFM needed to maximize the injectors.

A larger turbo will force more air at the same PSI than a smaller less effecient one.

You have alot of decisions to make before you pick a 'PSI" to push. Honestly PSI is a relative term that hahs nothihng to do with power level. 15 PSI on a 3/4' pipe is less than half the air of 5PSI on a 3" pipe

 

ohh ok, i am planning on runing the high output rx7 plugs, and i know a shop that can reprogram the stock ecu. I plan on upgrading to a t3/t4 hybrid. sorry if i leave a lot of stuff out this is my first turbo motor and google searching leaves alot of stuff out.

 

I ran 10psi before on the stock setup with just 3"down pipe and exhaust. It made 186hp at the 10psi. Then I installed my boost controler and put in my PFC and set the boost to 12psi and walked away with 213hp. The PFC was untuned so I don't think it made that much of a diffrence over the stock ecu. The stock ecu didn't run as rich as the pfc did.

 

I ran it at 14psi racing my friend on the fwy and back on the dyno. But this was after a intakemanifold upgrade and FMIC. Turbo didn't miss a beat but I have one of the 16V Rb20 turbo's.