S60 14L GT4708 what is a safe max psi boost ?

If you think about it that makes sense that is doesn't work that well with the jakes, the Jake relies on that open exhaust flow out of the cylinder, holding it in down stream doesn't let it breathe.

 

so i know this is reviving an old thread but it has a lot of great info. i’m glad to hear you like the 1.58a/r housing vs 1.32a/r as stated the 1.32 just is to tight for a good working 14l. my question is because a lot of cat guys love the housing of 1.45a/r on there 3406/14.6l engines. do you think the 14l detroit would be happier with a 1.45a/r vs your 1.58a/r just for the fact of getting some bottom end back and the power slightly lower in the rpm range. thank you

 

I dont come on here much anymore. Just stumbled across this.

I actually did eventually go to the 1.45 and was a great happy medium with good spool and not to much back pressure. I had a bearing go out in the 80/1.58 turbo. So I decided to replace with a 78 / 1.45. I liked this combo best and what is still on there today. For a 14lL seems the best over all combination.

12.7 is still better with the 1.32/75 unless your over 650hp