Hi termie,
If you do want to carry on with either the turbo option or Hiclone I think you need to consider a few things first.
Fitting turbos increases the bhp/torque but the internals of the engine need to be able to cope with the increased power.
I am aware that Fiat make a 2.8 turbo, but it does not mean that the normally aspirated engine (yours) has the same internals i.e.: pistons/crankshaft ect.
As for the other suggestion Hilcone I suggest you make sure the engine is running correctly otherwise you could do damage, I’m sure they will check that out before fitting anything.
Bearing in mind that the internals of modern engines are far superior to something say 10 years ago and if you are going to fit turbos they may say it can handle the extra power, they may not be wrong, engines are designed to handle more power than is produced when manufactured in standard form, but if you are reaching the upper limit of those figures then your engine will wear out quicker.
Personally I would say your motor home needs a good long run along the motorway
on a frequent basis, 6,000 miles in 18 months/2yrs it has not been used that much.
As for the engine being tight, engines now are capable of hundred thousand plus miles without any serious work being carried out, so your engine is nowhere near run in. They say modern engines are at their best around 40 to 50 thousand miles; yours has a long way to go before it peaks.
Engines do not like being sat idle for long periods of inactivity, starting them up without actually moving is bad news (condensation forms inside the engine) your better of leaving that alone, or go on at least a 50 mile trip (longer the better).
This or course is only an opinion, you decide.
MHS