I understand there are a number of people doing this rather quietly. I'm interested, and have discussed it in depth with some NW Bombers, and we're still in the "working out the details" stage. HDM48 and I are interested in dual parallel turbos, instead of the common series setup.
First gen engines can't get a LOT of fuel, like you can with a P7100. Instead, to achieve maximum horsepower available, you need to be able to burn all the fuel as well as possible, and reduce parasitic losses as much as possible.
Since one of the large parasitic losses is developing many PSI boost, it would be more effective to find ways of achieving sufficient airflow with lower boost.
My idea is to use the Piers camshaft, two smaller, wastegated (wastegate is very important here... the idea is to have as little restriction to exhaust flow as possible) turbos, strong airflow improvements to the head, intake and exhaust ports, and perhaps intercooler as well.
Also, in this mix, is changing the valve springs, and re-working the injection pump with a new governor setup for 3400 rpm, more advance in the pump to maintain efficient fuel burn at 3400, and running low boost numbers - probably not over 20 psi, while shooting for 300 to 350 HP at the rear wheels.
Just the increase in RPM, reduction of losses due to breathing difficulties, and improvement in timing, without turning up anything - should raise my truck from 217 HP to more like 290 horsepower.
With the improved airflow, I should be able to then turn up the pump, and make well over 300 HP, with NO smoke and egt being very manageable.
Before you comment on this, you need to realize that this idea is NOT conventional. It is, to be blunt, totally different thinking from what has been propelling much of the horsepower race so far. What's been happening, is that using injectors, pump mods, or electronics or any combination of them has been used to cram more fuel in, and then finding ways of cramming sufficient air through to burn it.
This is almost solely an effort to increase efficiency of the engine, reduce parasitic losses, to release the limited power that exists due to the the limited amount of fuel available.