Charger setup

[piespeed]

Im in the process of putting together a supercharger package for my car, in this case it will be a mini (classic). I'm in the process of making myself up some pulleys to drive a m45 charger from the new mini cooper s and plan to use a 'blow through' arrangement using a SU carb (from a metty turbo). The setup will be intercooled and will run around 12-14psi max.

However, being a bit of a novice when it comes to chargers and not thinking things through i have neglected to think about a mechanism to prevent over-boost when the throttle closed upon gear changes.

Several solutions have been suggested:

A traditional 'dump' valve or blow off valve, which i have reservations over due to size.

or

An external wastegate plumed into the boost pipes just after the charger.

Can anyone with experiance tell me if this is going to work, or if there is a better way of tackling the problem? The charger does not have an internal by-pass like other models.

Cheers - Andy

[mave]

A waste gate in thi sposition is exactly the same as a BOV / dump valve. The term "waste gate" is normally used for a turbocharger, where the exhaust gas bypasses the turbine to manage boost level without (inefficiently) bleeding compressed air from the compressor

[kenmorton]

Would sugest you get hold of a copy of Supercharged by Corky Bell. All the information you are ever likely to need in there including various bypass arangements.

[GreenV8S]

A standard dump valve will work fine, but if you can package it you're better of fitting a vac operated recirc valve to take the load off the blower while you're cruising. Otherwise they tend to run very hot at part load, which is the last thing you want for durability and power.