exhaust design
exhaust design
If anyone is interested in getting the formulae for making an exhaust to suit your naturally aspirated car, there is one book that has all you need to know. Four Stroke Performance Tuning by A. Graham Bell. Just be warned, no exhaust shop is interested in produceing the correct lengths or OD's so it is for people that can do it themselves. EA owners will have trouble getting the primary/secondary sizes right due to the single exhaust port, so just use the secondary OD from the head.