what is the safest boost to run on a stock obd2 b18b motor with stock fuel injectors? thank you... ive heard numbers like 10-12psi...

 

I wouldn't go higher then 8psi

 

Swap out the injectors first thing.

 

and replace them with what? thanks

 

something bigger, whatever the next step is for a ls motor

 

You're going to need alot of parts for high pressure of boost. Injectors,rods,bearings,pistons,etc. If you wanna do it the smart way.

 

Okay...I'll be the smartass....

The safest boost, is NO boost.

However, a stock LS bottom end has just over 9:1 compression. Which, with an all-aluminum combination, is low-compression. Basically, though, it depends on the turbo. If you use a small turbo, you can run greater pressures than you can with a big turbo, because the peak power levels won't be there.

What generally will happen, is you will run enough boost to cause detonation, which kills the cylinders. It literally will displace them to another location inside the motor. I've seen this referred to as "walking" the sleeves.

Safe, in general, is about 8-12 psi, depending on turbo, with a maximum of 300 horsepower. Anything over that, and your BMEP's are high enough that there is no margin for error. And, I'd highly recommend using a meth/water injection system if that is indeed your goal, as it will drastically reduce the likelihood of detonation, which will immediately displace the cylinders at that power level.

 

psi is an irrelivant number without knowing the cfm of the turbo used.


whp is a more accurate number, and it is ~146.304 whp. well according to the math. so whatever turbo you use, keep cranking the boost till you hit the whp provided. this will keep you to a 80% duty cycle @ 40 psi of fuel pressure (i.e. stock fuel pressure @ WOT in N/A form).

of course you can turn up the pressure and crank on the cycle till you get to 100%, and make more power. but the injectors will not last very long, and more then likely fail right when you need them.

 

at first i was scared to enter this thread but i see there are people that know what there talking about giving advice damn this made my day expected to see something like 35psi with a big intercooler lol good shit fellas

 

Well IMO i would boost at all on stock injectors and no fuel management. But i f you must boost on the stock i wouldn't go any higher than 5-7 Psi but thats still with using atleast an FMU.