ZDs, like most big 4-cyl diesels, don’t like revving. Most of us aim to have more torque at lower rpms, because that is where you actually drive the thing.
Saying that, without reading through 12 pages and 227 posts again, you started off by saying your Patrol is stock, apart from a 2” lift and 33s. I take it you now also have the EGR blocked and the swirl valves disconnected, but nothing else. If that’s the case then you are pretty much where I was with mine, prior to installing the MagicBox, but I still have my swirl valves connected. (Still waiting for someone to provide facts backed up by evidence that it actually makes a difference.)
I havenoticed any difference in performance with and without the EGR blocked. The only difference I do notice is a slightly different engine “tone” at low throttle and low rpm (which is where the EGR operates most of the time). At 16, your fuel eco is a bit high, but not entirely off the chart. (Mine is between 11 and 12 atm.)
A 3” exhaust (or the more commonly recommended 2.75” for a CRD) won’t make much difference without a tune, or if you’re willing to put in the effort, at least some other form of boost control e.g. needle valves or MB.
I don’t trust seat of the pants dynos. You’d have to convince me with a dyno chart that you have more torque after blocking the EGR.
I do understand where your coming from. I've lost count of the number of dyno's I've had over the years, many years ago I knew a guy with a dyno, I had an agreement with him that after I did a mod I got a power run at bargain basement price so that I knew what I had done added to performance, I cannot remember a backward step yet, I did get a surprise when the CCIC I fitted only produced 4hp, but the torque went up and came in lower, so it was a win.
Secondly the good thing about an ECUTalk is engine info is right there in front of you, so if you see MAFv go up for a setpoint after a mod you know it is working better.
Dyno's can be misleading, but if you have the same operator on the same dyno then that is a good start, but, a dyno does not measure driveability, ie, my old girl also spent a lot of time on another dyno with the same operator while a turbo was being developed, on the dyno we had it running at 28psi then 30psi then back to 25psi (now 24psi), sure the dyno charts showed improvement as boost went up, test drives were also done on road at 30psi then at a lower 25psi, you would be hard pressed to pick a damned difference, but I'm not driving around anywhere with 30psi and as said it now sits at 24psi and it feels great.
I have two dynos I use in my quest for improved driveability, my seat of the pants dyno which does work well and a stop watch dyno to time 60-80k then 80-100k then an overall 60-100k in 4th gear on the same stretch of flat road, that one tells a story completely.
