Frequently Asked Questions
- Is the Podifold system a complete kit?
No. The basis of the Podifold system is the cast aluminium manifold which securely and accurately connects the supercharger to the cylinder head. This provides the starting point from which a custom blow through set-up can be created.
- Why don't you supply the rest of the stuff I need?
Basically because there's other people out there making the other parts better than we ever could and you can probably get them cheaper than we can supply them anyway. We've worked closely with those companies to make sure our system works perfectly with their parts.
- So what else do I need to fit the carb version manifold?
To complete the system firstly you'll need an Eaton M45 supercharger off a BMW cooper. These are commonly available second hand as the standard charger was replaced by John Cooper Garages when BMW Mini owners purchased the Works upgrade kit for their cars. Next up you'll need a bottom/crank pulley designed to take both a standard v-belt and an additional multi-rib belt. The system was designed around the dimensions of the MED Engineering pulley and this is the one we recommend. To provide fuel to the engine you'll need a suitable carb. Being a pressurized blow through system you'll need one which is sealed. The system was designed around the HIF44 carb and plenum combination off a Metro turbo and these are regularly sold second hand with rebuild kits also available. The carb needs to be fed by a high pressure fuel pump and the easiest solution here is to source a petrol tank from a later MPI Mini which has the pump built in along with feeds for the dual fuel lines. The flow of petrol to the carb needs to be controlled with a fuel pressure regulator and the standard Metro Turbo version is recommended. One of the benefits of a blow through system is the ability to cool the charge using an intercooler and fitting one is highly recommended. There are many types available and choosing one is simply a case of finding one which fits within your engine bay layout. To vent the pressurized air created by the supercharger when at idle and low load conditions you'll need to fit a dump valve specifically designed for a supercharger system - turbo dump valves simply aren't big enough. Some form of electronic ignition management (Specialist Components, MegaJolt, Nodiz etc) is highly recommended but not essential if you've got a distributor that can handle the timing of a forced induction system.
- Can I fit this to my standard engine?
Probably not. Over the years standard production engines had various compression ratios all the way up to 11:1, way too high for a forced induction engine. To run the Podifold system you really want a compression ratio of around 8.5:1, which for most engines will mean either using dished pistons or increasing the combustion chamber volume in the cylinder head or a combination of both. The engine also needs to be in good overall condition. Remember, you're expecting much more from it than it was ever expected to do when it left the factory.
- Can I run this system using my standard gearbox?
Again, probably not. The weakest link in the Mini drive train is the well known single pin differential issue and it's well worth, at the very least, upgrading to a cross pin diff before running the Podifold system. From there you can upgrade all manner of gearbox components. A lot will depend on your driving style and the car's intended purpose.
- Can I use this system to upgrade my existing suck through set-up?
Yes. There'll be some additional parts to buy but your supercharger, bottom pulley and belt tensioner should all be fine.
- Can I use it on my 998cc engine?
998cc engine blocks are 3/8" shorter than 1275cc ones and this causes clearance issues between our manifold and the engine steady bracket under the master cylinders. However, we can supply a subframe raising kit which moves the engine upwards by 7mm and eliminates the problem with the additional better handling benefits you get from solid mounting the subframe.
- Can I use it on my MPI Mini?
Yes, but not without a lot of work. You would need to change the bottom/crank pulley to a twin v-belt/multi rib belt type and the water pump and alternator pulleys to the v-belt type as well as removing the brake servo and changing the entire ECU and fuel injection system.
- I've got a bulkhead mounted brake servo, can I still use the Podifold system?
No, it gets in the way.
- Why do I need a dump or re-circulation valve?
Superchargers are linked to the crankshaft with a belt, so it's always spinning, therefore, it's always pumping air and creating boost.
Problem is, you don't always want boost. That's where your dump/re-circ valve comes in. Under idle and low load conditions (waiting at traffic lights, cruising on the motorway, etc.) it opens up, venting the boosted air to the atmosphere or re-circulating it into the inlet of the supercharger instead of forcing it into the engine. It's open when there is vacuum in the intake manifold - basically when your foot is mostly or completely off the accelerator pedal. By not forcing fuel and air into the engine when it's not needed you'll get better fuel economy.
However, when there is demand from the engine (foot on the pedal, no vacuum in the intake manifold) the valve closes and all the pressurized air from the supercharger goes into the engine. You get boost, and you smile.
- Why do I need a massive dump valve? Can't I just use any turbo dump valve?
Small dump valves work great on turbo installations where their role is to quickly 'dump' the pressurized air in the system when you take your foot off the pedal and the throttle closes. This eliminates any back pressure on the turbine that could stall and potentially cause damage. However, a turbo doesn't create boost in idle or low load situations like a supercharger does.
- Why don't suck through systems have dump valves?
Dump valves are used to release built up pressure. The only place there's a build up of pressure on a suck through system is in the manifold between the supercharger and the engine. At any one time this manifold is filled with the air/fuel mix and opening a dump valve here would mean venting a load of petrol vapour into your engine bay close to a hot exhaust. Not a great idea.
- Why can't I use my standard HIF44 carb?
Carbs for normally aspirated engines are designed to work in a vacuum situation where the engine is sucking air through them. Blow through systems pressurize the carb by forcing air into it. If the carb isn't sealed this will cause petrol to leak out from the fuel bowl. Standard HIF44 carbs can be converted by using the turbo service kit with the cup washers turned the other way, fitting our dashpot sealing gasket and sending a feed or pressurized air to the fuel vent connection on the carb body.
- What gasket do I need between the supercharger and the manifold?
Genuine steel gaskets can still be bought from BMW dealerships, part number M126.96.36.1990.044
- How much does it weigh?
A bare, machined Podifold casting weighs around 2.7kg.
- What size silicone pipework do I need?
The diameter of the outlet stub at the back of the manifold is 45mm to match the inlet size of the Metro turbo HIF44 carb plenum.