Westcoaster - not a hijack at all, this is exactly what the thread is for, to give a bit of an insight into the "black box" that Performance Diesel Injection / Giles' processes seem to have become. Giles would like to be more in touch with his customers - especially with us, since the performance side of things is his baby - but he's super busy most of the time, and I type a lot faster than he does :lol:.
As far as your particular application, it sounds like a sweet ride. My brother would absolutely love a system like that - actually, it's just about the only way I could ever convince him to drive anything German. :wink:
My understanding and experience is that our engines don't prefer to rev super fast; conventional wisdom is that the slower a diesel engine runs (all other things being equal) the longer it lasts. There are of course provisios and stuff, I'm not trying to start an argument on that point, since there are plenty of people with very long-lived AAZ's that run way higher than 3,500RPM every day of the week.
So that's one point with regard to reliability. As far as what we can give you that another shop can't with a regular rebuild? First, you saw the videos. Basically, we are just more meticulous than many (We're of the opinion that "most" or "all" is a fair word, but that may be opinion) other pump builders. Rather than just replacing damaged components, Giles examines the entire pump, replacing components which WILL be damaged soon, components which can't handle the stress we/you are going to put on it, components which can be swapped out but don't strictly have to, etc. He uses a combination of OEM components and custom-fabricated bits in order to get the job done to his specifications, and he regularly tears down the pump multiple times in order to fine-tune. That's the part you don't see in the video, Giles testing the pump, writing down the numbers for specific RPM's, bringing it back to his workbench, and stripping it down again to make further adjustments in order to maximize the fuel curve all through the range which your pump is going to see on your engine.
Short answer:
- We can give you more fuel, where you NEED it, rather than just "more fuel across the board".
- We can give you 30-40% (or more) useable horsepower
- We can give you better fuel efficiency (Amount varies with pump, there's only so much we can do to tweak, and we can't be accountable for the weight of your foot

)
- We can give you a higher and wider useable engine/pump speed range
So yes, 3500RPM is quite reasonably possible, at a nominal level of reliability. Everything is a tradeoff, of course - if you're going for complete reliability, an overbuilt totally-stock setup might offer better engine longevity than any performance system, one can never be sure. But as far as the sweet spot in terms of high performance, high reliability, and best bang for your buck... well, that's what we can offer you that a lot of shops can't. They might anyway, but unless they've got the experience, track record, and customer list to back it up, I would remain highly skeptical.
Also, I apologize in advance if any of my after-hours posts wind up with more errors than usual or anything, I'm trying to make some dinner and stuff while I hammer these out.
At any rate, does that answer your question?