Thread: supercharger PSI boost?!?

Supercharging an engine designed and built to be naturally aspirated is a complex and frustrating business.

You have added more air so you have to add more fuel to maintain correct fuel mixture.

You have added compressed air which is at an elevated temperature. You may need to fit a modified ignition system to cope with detonation. This depends on the temperature of the mixture and the pressure. You may need to buy or fabricate an ignition boost retard system to the distributor if you are using one.

If you add an intercooler to the intake system you have cooled the intake air, made it denser, and need to add more fuel to maintain correct mixture. You also now have pressure drop across the intercooler so you may wish to increase initial boost to maintain the manifold pressure desired. Start again at the beginning of this paragraph.

All these are assuming that the engine is in good enough condition to be pressurised. If not, then we can go back to the very beginning and pull and rebuild the engine to a satisfactory standard.

Otherwise, if you just want to bung on a blower to show off at the tavern, fit one, but keep the boost below an added 6-8 psi.