Is it possible to retrofit a supercharger on a 2002 XJ8 Vanden Plas? Thanks

 

It might be doable, but don’t expect the same power levels as for the R version.

Here are some of things you need to think about, though I don’t have that much knowledge about a NA car. To stay optimistic you will be lucky if:

-The NA block has supercharger mounts, though someone on this forum had to make his own mounts.
-You can put a significant bigger upper pulley to reduce pressure from the SC, as the engine compression is very high of an NA.
-The coolant hoses that interconnect to the intercooler hoses are the same, so you can swap.
-The intercooler radiator/mountings are the same as on a R so you can re-use
-The engine will start fine without the air assisted fuel injectors, as this should probably be disabled. You might need to use the injectors from a R, but not sure how these will work with the ECU from the NA.
-The single fuel pump will be able to handle the higher pressure/load, don’t forget, the SC itself also consumes power, so the load needed is much more….
-In relation to the above, that you can swap the fuel line from the R with fuel pressure release valve on the return line to keep the fuel pressure constant.
-The ECU will be able to handle more air flow (probably can though).
-The NA tranny you have will be able to handle more torque (and engine internals....)
-You might be able to re-use your original TB, but probably need to check how to (or not to) work with the air assisted fuel injectors.

The intercoolers will probably mount, and you can buy stuff above from a R (i.e. intercooler/hoses) to make things fit. Pulleys etc can be interchanged, and will be easy to connect the SC coolant pump.

Important here is that you will not reach the XKR output, I think you will be lucky if all works out to achieve 40/50 bhp more.

Have probably forgotten some, and hope that the big ones should have been mentioned. Of course this is a big operation, and needless to say probably more expensive than exchange your NA for an R.

 

I suspect that fitting a s/c to a n/a engine is just not viable. The only way of success is to fit a s/c engine and ECU. This is because of the extra engineering within the s/c engine. Pistons are hi spec Marle, con rods are equally over engineered. It does not have variable valve timing. You could look into fitting a Rotrex aftermarket system, but pistons would have to be changed, and a re-map. This would be far more expensive than locating/fitting an R engine.
Pipe dream? Sell the car, buy an R.
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KTM 250EXC

 

The engine compression will stand in your way. the NA compression is higher as most NA vehicles the Supercharged is lower as most Supercharged and Turbo vehicles.

I looked into this a long time ago for my 1999 XJ8. I dont have anything in front of me now but I believe the NA compression was between 11:1-10:1. The Supercharged was 8:1.

I was told the stock XJR Eaton Superchargers would not work with higher compression, so you would have to change out the pistons and other components to reach the XJR compression.

I have the write up with all my other Jag do it yourself packets. I will try and find it soon and give you the full story.

But overall it came down to just buy an XJR if thats what you want because money wise it would be an extreme custom job.

 

as an R owner, I cannot think this would be a wise conversion....waaaay cheaper to just go out and buy an R....I got a peach on ebay for $11K last year, 2002 with 78K in almost pristine condition. Cost me nothing more that a set of tires and 3 suspension bushes. The CR on the NA motor is far too high for forced induction...even low pressure induction would cook your pistons and valves quickly and I'm also thinking underfuelling would increase the chance of pre-ignition.