Two modified boxsters on the dyno

[seningen]

Originally Posted by deathsled986

OEM 986/996 injectors are only 230cc/min if I'm not mistaken which IMO are woefully undersized and at the practical limit. At 100% duty cycle and a fuel pressure of 43.5psi 6 230cc injectors are theoretically only good for around 290bhp.

I'm not surprised to hear about modded 3.4 lean issues at all. You should be completely out of injector given the math.

**edit**

I just found that fuel pressure in a 996 is actually 55psi, so that should give a little more headroom, like 6 more bhp.

I'm surprised Porsche put such a small injector in these cars. I've always been under the impression you really don't want to run an injector more than 80% IDC just so you have some additional margin. That would mean you really want an injector around the 290cc mark. That would run a motor comfortably at 300bhp and give you room to grow up to around 370bhp.

So the real question then is if Woody's boxster is setup up for 55psi or not.

Mike

[edc]

There's a chap on Boxa.net who built his 3.2 into a 3.4. He's a mapper and engine builder by trade and he had no issues with injector duty cycle as far as I know.