How Much Boost

[Guest Heater]

How much boost can I run on a stock motor? I just got the motor back from the machine shop and the bottom end is all stock, but i really was wanting to go with a bigger turbo if it would take it.

[materchan]

most perople say 10psi before it leans out, i've heard of 12 but 10 is a safe bet

[Guest bastaad525]

stock MOTOR can take a lot of boost... 15... 18... 20psi, maybe more, but those are numbers I've heard, with the fuel and good I/C to support it.

 

 

stock EFI, on the other hand... yeah, 10psi is like the ragged edge of safe, w/o an I/C. I ran 10psi for quite a while on stock everything and no I/C, on the dyno it did get lean enough to be potentially dangerous, after about 5000rpm. Actually that wasn't 100% stock, I did have an upgraded fuel pump... which oddly, didn't seem to make any difference over the stock pump, which I had also dynoed with.

[Guest Cronic]

An upgraded fuel pump wont do anything if you're making under ~350whp. As the stocker is good to ~400bhp. Upgraded injectors would actually help you out much better as they are the first bottleneck you have to get through.

 

Stock engine can take as much boost as you can throw at it. PSI isn't the factor here, power is. Your stock internals tend to give out around 450whp from my understanding. The HT Cast pistons are the weak point.

 

There is no "right" answer here, as everyone's setup is different. Like I said I was running 15 for almost a year before I upgraded to secondary injectors.