What is the highest boost you can run with stock turbo and 4B11 internals thats considered safe for the motor and efficient for the turbo?

I know stock is around 21.75 psi, how much more boost can you dial it safely?

 

Ive been running 25psi tapering to 18 by redline and havent had a problem. BTW, stock spikes to 23psi and tapers to ~15.

 

how long have you been runing this set up? and what supporting mods do you have?
im currently tuned for 23 tappering to 16~

 

Check out the Evo X dyno section there is a lot of cool information on ppl running stock blocks and turbo and what they are pushing.

 

I'm currently at 26.5 psig peak tapering to 19.

 

Thanks guys

 

I'm hitting 30 tapering down to 22, with full stock exhaust. i have boost pill

 

when are you suppose to use boost pill?

 

Im tuned at 26, spiking to 27-28, tapers down to 19-20psi by redline (3-port).

 

tl, whats your dyno?

 

I boost at 30 psi no problem. Only thing that sucks is the stupid warning that's pops up.

 

I did a road tune, so no dyno numbers..

 

I wouldn't run more than 30psi (on E85)... and even then I think that is pushing it.

Be very sure that whatever you are spiking, that it never goes higher than that (i.e. when weather changes). The stock turbo is capable of making over 34 PSI. No, you aren't going to be making more power at that level, but it will be more than enough pressure to vent your cylinder block.

 

there's a fix for that.... and I found that warning didn't usually come on until 31psi... so be careful

 

Some good info