You binned egr valve? Looked at fuel pump? Intercoolers?
How about water injection?
Are you running water injection? If you are, what are the results (mpg/bhp)?
I've only ever done in on my Mazda Rx7 back in the day, that was very modified with a big turbo and uprated fuelling all the way. We remapped it to the water, could chuck a load more fuel in and added around 20rwhp IIRC
Happy times.
Wonder what the effect would be on a 300tdi; suspect any gains in mpg would be negligible. Kits available on the bay:
200 psi DIESEL water methanol injection kit with solenoid and super atomizing on eBay!
the 300 tdi engines power potential is limited by the head bolt strength(and head to block seal), even if you use hd bolts the block fixing fails.
With turbo diesels 100bhp/litre is nothing special or hard to do its getting the architecture of the engine structure to hold up to it and getting the fuel delivered which the ve pump is capable of
did one I was gutted, big unreliable junk that likes to crack its block around the mains6.2 gmc v8