Realistic tuning options of d3 4.2 tdi
 

Good evening all,

I am looking to gather some serious information / input on the known options for tuning the d3 a8 4.2 tdi?

The car already has a map and I know there is an option to also map the gearbox.

But, if you had say £2-3k to spend on tuning, are there turbo upgrades etc worth looking into? Do we know what realistic figures we could likely achieve?

I know there is an argument to start looking at the s8 route, but this is an itch that is interesting me +++

From what I remember when I was looking at it when I had 4.2TDI, it's getting rid of DPFs and changing exhaust first, then high pressure fuel pump, apparently you can fit one from D4 and then can run higher pressure and delivery rate. Air is not the he limiting factor so no need to start with turbos and by the time you get to turbos you need to change intercoolers, injectors and will probably run into too much heat under the hood.

Bigger turbos, Remap, Exhaust will give big numbers but at a cost. A decent map will give plenty of power and torque. Speak to specialists like MRC or VRS who can give an idea of figures

In the same boat, as mentioned dpf and mufflers emptied, egr closed, blanked, take off the air plenum manifold and clean, remove flaps and use actuator adaptors to stop codes, good remap, that engine on its best day it would probably touch 390-400hp max see BTR engine darkside devlopments which is similar but different intercoolers ours is BVN. Gtb1749vk limit per turbo is around 200hp so its not getting over 400hp as standard. Darkside devlopments are working on a 4.2tdi btr project at the moment so worth a watch they remapped the BTR with standard turbos to 400hp. Going beyond that, I can't imagine much change left of £5000 turbo modifications including the tuning.