1994 Jaguar XJ40 3.2 Sport - Rolling resto daily

Cool, sounds like a pretty straight forward budget turbo setup planned there. I'm working on my turbo conversion at the moment, it's certainly a fun project but it's quite a big undertaking both in expense and time. I'm no expert but I've done some of my own research on turbo charging, here are a few thoughts...

I looked at used turbos but actually found it better value to get a brand new ebay chinese one, just a basic T3/T4 hybrid with a journal bearing and no internal wastegate, £83.99. Luckily for my MX6 there are off the shelf turbo exhaust pipes that have T3 flanges. I think routing the pipes will be more tricky on the XJ40 as there isn't a great deal of space between the exhaust and chassis rail, looks like you'd have to stick with a log type manifold and get rid of the pre-cats in the standard downpipe so it plumbs into the center cat.

I've bought an FMU rising rate fuel pressure regulator to get enough fuel into my 2.5 V6 under boost, went for a OBX Racing 12:1 that I had shipped from the states. I think they are a decent option to get things boosted on a low budget, but they are best for smaller engines on relatively low boost. As you may know, a 3.2L will need a high ratio FMU, and at 8psi you will be running very high fuel pressure, possibly too high. The injectors could have problems with distorted spray patterns, and there will be stress on all the fuel line components. I've got an ebay external wastegate, it came with an 8-11psi spring but I swapped it out for a 3.6psi one for starters to use with the FMU. One good thing with an FMU is that if you can use the standard injectors and ECU, but I can see why you'd want bigger injectors for more boost.

There are cheap ways of doing aftermarket fuel management. There is the quite well know Megasquirt and also budget Microsquirt. An even cheaper option is something known as a Speeduino, it basically uses an Arduino micro computer to do the processing required, the kit costs around £75-100. I'm not going for that yet as getting one of those setup, working and mapped is a project in it's own right. Obviously bigger injectors would definitely be needed for this, but you could set it up for whatever impedance you need.

For the turbo oil feed I used a sandwich plate adapter with 1/8 NTP holes, it mounts between the oil filter and housing. For the drain I've done what you are thinking of, drilled a hole in the sump and put a 10AN bung in it.

The intercooler is of course a simple bit of kit but I found that I had to put quite a bit of thought into how to run the charge pipes. I've ended up making a few modifications to the frame and offseting the raditor to one side to get the pipes past it. I went for a same side intercooler as the turbo and throttle body are on the same side of the engine, keeps the pipework shorter and more tidy. On a '40 I imagine there will be a fair amount of pipe required.

Have you thought of going supercharged? You could potentially use the kit off the X300 XJR and you wouldn't need any custom exhaust. The Aston DB7 used an engine based on the 3.2 AJ16, with a supercharger.