Giving this some thought. Has anyone done it?? So my theory is transplanting a supercharger and manifold off an XJR onto my X300 sport 3.2. The obvious would be bigger injectors and ecu re-map. Do we think this is o bolt on option onto the 3.2 aj16

 

MAF meter will extend into the saturation curve on the present one , Headbolts , Valves and Valve seats , Cam ? , Stronger Crank if not the same metallurgy of the different S/C crank , optimized compression ratio or was that to limit the mechanical power limit ?

 

Aston Martin did it with the DB7 didn’t they?

 

I think the pistons are different too.

The compression ratio on the SC cars is lower as I recall as well, so just bolting on the SC parts would cause severe detonation.

 

Mmmmm. some good points. But in my experience as a mechanic and a shop owner is lowering CP ratio is a good idea but all the other engine refinements are not really required if you keep within a reasonable boost range. I have done many turbo installments to standard engines that hold together well. A jaguar engine is well designed and built I would be shocked if it could not handle some mild boost.

 

Correct......

 

As well as all of the other issues suggested above, the block of a 3.2L engine doesn't have the bosses machined to bolt on the supercharger mounting bracket. Fitting a complete XJR6 engine, harness, ECU, MAF and in-tank fuel pump assembly and control relay would be a better option. This is especially true if the donor car has a manual transmission.

 

If I remember correct the block was designed with the thought of producing a diesel variant so the bottom end would hold up. Agreed with the idea of keeping the boost levels low due to the CR.
Also I think there is about 20% capacity left in the ECU fueling map?

 

About the sc fixing bosses; I would presume the block raw casting is the same across different versions of the engine? so the bosses are in the casting "just" need to be tapped and threaded?

on internals :
3.2 crank is casted, 4.0 and 4.0SC are forged (and the same IIRC)

3.2 and 4.0 cam has the same part number so they should be the same
4.0 and 4.0SC cams are same profile and with different timing (as there is adjustable pulleys this should not be a problem) at least I _think_ this is the case

3,2 and 4,0 valves (at least intake) are with same part number
4.0 SC has different part number but what is the difference that I do not know

4.0 and 4.0 sc have forged rods (again IIRC) 3.2 no clue

 

Yes, the cast bosses are present on the blocks of naturally aspirated engine. They just aren't machined.


I'm not sure what is meant by the statement about "20% capacity left in the fuelling map". Supercharging a naturally aspirated engine should result in a an airflow increase greater than 20%, so whatever "capacity" is being referring to, would be exhausted.

 

Lower flow rate NA injectors Vs. the higher SC injectors from my understanding the ECU will adjust the pulsewidth to keep your fuel trim at 0.0

 

The fuel injectors fitted to the supercharged engine are of a much higher flow rate than those fitted to the naturally aspirated engines.

 

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I would imagine that supercharging is to gain additional power but how much more power can this conversion produce, and, considering the costs in terms of time, labour and parts, would all such efforts be worthwhile beyond proving that such a project is doable? Saw some discussions entitled as close to a DB7...(aka the X300 XJR project) in the XJ40 Forum with similar thoughts about supercharging a 3.2 engine.

I would be more tempted to see someone replicating or surpassing Dr Jag's efforts in achieving 430kw power and 700 Nm torque in an XJR. See previous discussion here where Greg Parsons has a great write-up about his Project XJR-6 "from the wrecking yard to the race track".