I have a 1.6 8v Nova GSi, it's got a Blydenstein B+ head, kent cam, standard manifold, straight thru exhaust and standard GSi back box.
I changed the back box yesterday for a HKS type unit, it looks well but I feel I have lost torque.
I don't know much about exhaust design/performance theory but I have heard a lot of you guys talking about pressure in the system and effects on torque. Could my set up be too free flowwing now?
The system is far too loud (louder than my Dads Grp B HSR) so I'm going to fit a centre box, it will be interesting to see if this has a positive effect on performance.