Is 9 psi to much boost for a stock 5.3 silverado?

Answer 1

9 psi is pushing the limit in a non-intercooled platform. 9psi is almost 3/4 of a whole extra atmosphere. that translates into almost 230 psi peak compression in a relatively large combtion chamber. its not as though you're dealing with too much piston compression but, the 5.3 is just a stroked version of the 4.8 vortec. my advice is always put the highest octane in your boost machine and invest in some head studs and full metallic gaskets and whatever you do, don't push 9psi until you can accomplish some sort of cooling. (I.E. intercooler or methanol/water injection) the problem you will run into is detonation. do yourself the favor. prepare your engine before you install/adjust boost. it may seem expensive but, i garauntee it'll be cheaper than a new engine in the long run. I'll give you this: you will be dealing with a torque monster so good luck and have fun burning tires