New Project - Tuning my 3.4L for POWER

[insite]

Originally Posted by The Radium King

variocam+?

nope; i have a 3.4L from a '99. i have varioRAM (which is hooked up & functional), but only standard varioCAM.

[Topless]

A good project to investigate and a common problem on 996/Boxster conversions.

Some observations while running regularly with 3.4L Boxster conversions and 987 Cay S 3.4L:

The 987 has a nice wide, fat torque curve which allows them to put down power early on corner exit. A 996 3.4L tends to have a more narrow torque curve requiring more shifting to stay in the sweet spot. I suspect a well tuned and displacement-matched intake and exhaust along with software remapping will fatten up the torque curve and make the most out of a 996 3.4L in the Boxster.

One problem that has been reported is sonic pulses from the valve train traveling back up the intake and actually fouling the MAF sensor readings. Does the intake require a helmholtz chamber to neutralize these pulses?

[insite]

Originally Posted by Topless

One problem that has been reported is sonic pulses from the valve train traveling back up the intake and actually fouling the MAF sensor readings. Does the intake require a helmholtz chamber to neutralize these pulses?

interesting observation; i wonder if that is why there was a resonator on the original intake? anyway, i should be able to log MAF voltage vs. RPM at WOT. if there are any anomalies, i can probably program them out.

[BYprodriver]

Originally Posted by insite

nope; i have a 3.4L from a '99. i have varioRAM (which is hooked up & functional), but only standard varioCAM.

Insite is your MAF housing tube I.D. 3.5" ?

[insite]

Originally Posted by BYprodriver

Insite is your MAF housing tube I.D. 3.5" ?

yup. i use a BMC airbox w/ silicone plumbing to a 3.5" MAF housing.

[The Radium King]

996 is 3.25" ID, no? and, from what i recall about your install, your maf housing is located right after a bend?

[insite]

Originally Posted by The Radium King

996 is 3.25" ID, no? and, from what i recall about your install, your maf housing is located right after a bend?

pretty sure the 996 is 3.5".

MAF sensor should be at least 1 and ideally 1.5 pipe diameters from a bend. in this case, that would be 3.50" - 5.25". i am at the upper end of that range.

EDIT: if you look at the 996 MAF housing, the inlet is a funky shape and VERY close to the airbox itself. probably not a comparable measurement environment to the one below.