just wondering what size injector i should use on a 5.3L truck motor with 8psi on a bottom mounted turbo. keep in mind that this motor will be used primaraly for towing and i would like it to run on cheap gas if at all possible.

 

the octane wont affect the size of the injectors, the HP levels will.
my guess is 36lbe'rs, but not sure casue i dont know the HP level your shooting for.

first you are going to have to pull alot of timing for 87 with 8psi, alot.
whats the CR of your 5.3 engine?

 

You wont be able to run 87 octane period so get that out of your head right away. The STOCK 5.3 has pinging problems on 87 let alone something with 8#s boost.

 

For the extra 15 cents a gallon I can't see NOT running 93 octane. What did it cost to build that up to the level it's at? A lot more than a couple bucks per tank extra.

I would consider a set of 42's. Good insurance. Especially being on a built motor.

 

42# injectors

 

Steve i thought you were in Bootcamp..........???? they let you on a computer to post on Tech????
Kyle