Interesting conversation guys. I am just building an engine for my 500 AC that I am converting to be a rally car.
As I am forced to run a 29mm restrictor and cannot port the head, I have to run as high compression as I can and flow as much air as possible, up to say 5000 rpm when the restrictor really begins to limit the air flow and boost.
I have CPS forged pistons with 10.5 compression and am starting with the Garret GT1446, although I have a GT2056 and a GT25 to try (but expect them to compromise the low speed torque too much). The twin intercoolers are being changed for a front mount, and the 500AC injectors are already larger than stock (I believe). Target is 230hp and 350Nm, but I am not sure if the restrictor will allow the airflow ...
Anyway, a lot of sense being spoken by Dan and Griffs. I wanted to know if you are running the Motec M400 and if it can still run the speedo, gauges etc. Also does anyone do uprated head bolts and head gasket ? I will be using race fuel so a lot of boost anf ignition around peak torque !