R53 Turbo Build – Part One

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Preparing the car for conversion to turbocharging requires removing all of the engine ancillaries, inlet and exhaust manifolds. Luckily this can be done with the engine in place, this does save a lot of time but having a lift available does make life a lot easier.

The first stage is to remove the front end of the car this includes draining the air conditioning and cooling systems. I’m sure some people will ask about wisdom of losing the air conditioning. There are turbo kits that retain the air con but in general this requires adopting a compromise solution for the intercooler. It’s true that you could adopt a top mount intercooler and retain the air con but in my opinion a TMIC is a triumph of packaging over function. Placing the intercooler directly above the largest heat source in the car isn’t an ideal solution. Subaru as an example used a TMIC on their road cars but switched to front mount for their competition vehicles.

After removing the bumper, under tray and the crash structure the first item to remove was the air conditioning pump. Once the refrigerant has been drained from the system (in the correct environmentally friendly way of course) and the drive belt removed, taking the pump off itself is pretty easy.

The next step was to remove the alternator as the water pump would be in its place after conversion, again another simple job.

The final job for the front of the engine is to remove the supercharger and water pump, although not a complicated thing to do the combination of both items is quite heavy and a bit awkward to remove (mostly due to the water pump on the back of the supercharger). With the charger removed the next step was to take the belt tensioner and the idler pulley from the end of the engine. The tensioner is not that easy to access making the job a bit of a pain.

With that job complete, I could then start putting parts back on the engine starting with the Cooper drive belt tensioner. The next part to bolt up is the water pump again from a Cooper. I’ve seen a few people on the interwebs question the wisdom of using a water pump from a much lower powered car. At this point it’s probably wise to have a think about what the water pump and more importantly the water in your engine is doing. Moving a large volume of water around the engine only really helps if you have a very efficient radiator to lower the temperature of the water as it passes through the core, if the water spends less time in the core it stands to reason less heat will be removed. Having a more efficient cooling package will keep the engine running at a sensible temperature even with a low tech water pump. The water pump doesn’t really represent a huge parasitic loss (compared to the supercharger) so your fancy electric water pump doesn’t really gain you anything in cooling system efficiency but does make everything somewhat more complex.

With the water pump in place the alternator is the last part to bolt onto the front of the engine and yet again it’s a Cooper part, no issues with this from the keyboard warriors as it has the same output as the Cooper S one.

Front End Build Up
Front End Build Up

With the water pump and alternator using the mounting locations from the Cooper the dipstick needs to be moved to the alterative location too. This is a definite bonus as the Cooper S dipstick (both it’s location and design) is really poor. There are many examples of people who have experienced the dipstick snapping meaning the sump has to be dropped to remove the broken metal parts.

With the dipstick in place the next part to be refitted was the inlet manifold. With the removal of the super charger and bypass valve a much simpler induction system can be used. The inlet manifold is a reworked Cooper S item with a modified flange that allows the throttle body to be bolted directly onto it.

Before the new exhaust manifold, turbo and downpipe can be fitted a few more parts need to be removed. The coolant expansion tank needs to be temporarily removed and modified to accept a feed pipe from the water output of the turbo.

The exhaust manifold and heat shields need to be removed to allow the 3-inch diameter down pipe to be fitted. Having previously fitted the manifold with just a set of axle stands in my garage, this is definitely one of the jobs that are much easier to do with a lift!

The final job for this stage of the built was to remove the plastics at the back of the engine bay. This might seem like a simple job but actually takes a number of hours, the base being particularly stubborn to remove, as the locations of the bolts aren’t that accessible.

Front End Complete
Front End Complete

I’ve tried to highlight the main jobs required; at this stage we’ve built up the majority of the ancillaries on the front of the engine and removed most of the parts needed to fit the turbo. This might not seem like a lot but even with all of the specialist tools needed and a lift it’s still over 7 hours work.