I'm in the proccess of street porting an s4 motor for a t04r and i'm thinking of trying some things with the exhuast ports.



my goal is 500-550+ whp pump or race gas. doesn't matter

the car isn't my daily driver and the motor is going in a 91 na.

Not sure which efi yet. Was thinking of the tec3 but a its little $$ so i'm looking at microtech. i want windows based software.

The car will be used for as many forms of racing and i can put it in but its gonna see more highway battles then anything.



Anyway i'm thinking of not really porting the exhuast BUT squaring the leading end of the port so that it sorta opens suddenly causing the pulses to spool the turbo faster. Whats the thought on this?

 

if you port the exhaust, you should also port the inlet runners a little bit, maybe just polish them up and get rid of the roughness.



I dont know about advancing the exhuast port, but its gotta eat good too