Upgrade bigger turbo

Hello ,

Firstly, I am sorry for my Engilsh

I have a Ford Ranger 3.2 diesel engine . I upgraded bigger turbo ( bigger compressor blade and housing but keep turbine side same with stock turbo ).

I tried to remap stock ecu but stiil got a boost issue . Boost was dropped then ocsillated from 2500rpm up . My boost target is 2.3 bar but the actual boost is highest 2 bar then dropped and ocsillated arough 1bar -1.2 bar ( boost gauge) . The Ranger was really power and quick respond from 1500 to 2500rpm but loss power from 2500rpm up to 3500rpm .

I have a queston that do I need to scale maf sensor when I replaced bigger turbo for this diesel engine ?

If have scaling maf , how do I do it?

How to fix this boost dropped ?

Thanks for advices,

Hi Duc,

What software are you using to tune? Hp tuners?

You will most likely have to rescale the MAF sensor for accurate fueling as the larger turbo will be producing more airflow, probably mostly in the higher RPMs, possibly less in the lower RPM range.

Without seeing your actual tune I'm only taking guesses but,

Could you possibly be hitting torque/load limits? Is your wastegate control tight and properly set up?

If you have a .hpt file post it up and I'll see if I can find anything.

It sounds like you either have some issues with the boost control or alternatively as Alejandro has mentioned, you may be hitting a limit somewhere which is causing your issues.

The MAF sensor may not be reporting 100% accurately but this shouldn't be your issue unless you're exceeding flow capability of it. Log your MAF ourtput and make sure it isn't pegged at the maximum value.

Hello,

Thanks for all advises, my turbo is VNT type with electronic motor control .

With electronic control , you can explain me the percentage number on" boost pressure precontrol vavle table " and can I adjust it for holding boost at high RPM .

I have a other question about boost for diesel engine that : the boost will be reached target 2.3 bar at 2000rpm and it is maintain from 2000rpm up to 400rpm , is that correct ? ( as example )

The air intake temperature will be input data to limited boost pressure and which maximum C degree air intake temperature can get for turbo diesel engine ?

Regards,

Duc