The pistons are different & so is the IP. The head & injectors are the same. The engines are so over engineered that the NA engine is fine to be lightly boosted. The head is the limiting factor in any case.
I would not worry, I would just bolt the turbo manifolds onto the R2. Boost control is via the internal wastegate. On a diesel though boost is really controlled by fuel, the wastegate is just there for protection for over boost.
The turbo injector pump has an aneroid chamber which is connected to the turbo outlet so it senses when the turbo is boosting and increases the stroke to inject more fuel.
However, when the aftermarket turbos are fitted, the tuners simply increase the governor fuel amount & maximum fuel amount. It works, the downside is that if you floor it before the turbo is on boost you get a black smoke dump. If you ease onto the power it its not so bad.
With the turbo IP, the aneroid allows the engine to come onto boost before adding the extra fuel. This is also why the wastegate is needed. More fuel would keep building more boost which then increases the fuel until the wastegate opens.
Using the NA pump, the fuel has a set limit, so no wastegate is needed.
84 626 sedan FE SOHC turbo - Sold, no time to finish
84 626 sedan RF diesel - Sold, no time to work on it.
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