If you look at my mileage numbers above you will see that they were better on gas. They also would probably make better low-end torque if that awful mess of an upper intake manifold were to be replaced with a decent aftermarket one and some ITBs.

Some day I intend to build a max-effort 6-port with a custom upper intake manifold. I saved 2 sets of irons to practice with for the porting (filling the top of the aux ports will probably prove to be the most difficult part).

Be careful of the comparison...
The 4-port was using a "heavily modified intake setup" - that's already a big advantage.
Most of us know the stock intake manifolds are pretty restrictive.


-Ted

Ah, missed that part. :icon_tup:

I apologize that I don't have numbers for a stock 4-port, I have one right now (slated for a friend), but it is too much work to put it in the car (and I don't want to give up the power). I do know a guy who put down 185 WHp @ 7200 rpm and 145 Wlb-ft @ 5100 rpm on a carb'd 4-port (with completely stock ports on a Mustang dyno). However he was not running a stock intake manifold either.

The comparison is not very fair, but the 6-port did have 9.4:1 rotors while the 4-port was running 8.2:1. They had similar tunes (same ECU). I would love to see some dyno curves from built 6-ports.

I have one from a friend with fully ported 6-port, custom intake w/ ITBs, MicroTech EMS and stock ignition. I can't scan the curve right now, but it made 142 WLb-Ft @ 6600 rpm and 195 WHp @ 8400 rpm (Dyna-pack dyno).