3lt Nissan Patrol Exhaust

My friend if you can get 32psi out of it i would be running the other way before it goes BOOOOOMMMMMM !!!!

I know it is different vehicle but hope this helps in some way.

My 4.2 Patrol is set to max 14psi and at no time does the turbo "bog down". If I stick the boot into it then the boost just goes up, keep the boot in for any length of time and so does the EGT's. Also if I leave it in too high a gear and labour things, the EGT's will similarly rise.

I was worried about running my 4.2 at 14psi but this seems ok as I have now got 360 000km on the clock all with modified hp figures but only the last 100 thou with the 14psi (was at 11psi from new). Each engine model re-acts different to differing boost levels, someone has put a link up to Lonard's Auto and I would definately call someone like him to get guidance surrounding your engine.

Regards,
Trevor.

Captain Chaos,

32psi is way too high and I’m surprised it doesn’t go into limp mode after that.

The reason your boost drops under load is because the ECU reduces boost to promote EGR. The VNT system is completely ECU controlled unlike a conventional waste gate turbo like the 4.2 and Navara use. What you are seeing is normal, but the boost level is too high and you will have problems such as leaking intercooler or blowing off or splitting cooler hoses or possibly worst.
There is a simple fix for this problem and you can adjust your boost to a safer level. I run a maximum of 18psi under full throttle at 4000rpm, but my boost rarely goes over 15psi. Driving in the city, I don’t let it go over 9psi. My EGT’s rarely exceed 250C in the city and 400C on the highway and my boost doesn’t drop under load.
This is how I did it
18psi should be a safe limit for an engine with 17:1 compression ratio, but for long engine life I run the lowest possible boost to achieve acceptable EGT’s which I’ll never let go over 450C.

Chaz's Patrol