987 Exaust Manifold on 986 3.4L

[insite]

i am pretty sure the headers i'm using are sized right for my 3.4L. i am, however, obviously down on power compared w/ 996C2's and Cayman S's (they pull my on the back straight at road atlanta). since my headers are cheap ebay headers, they were my first suspect. i ran some calculations, though, and i'll be damned if they aren't a GREAT design for the 3.4L.

i just ordered a wideband o2 sensor so i can check to be sure the 996 tune is working right w/ my setup. with my intake & exhaust, this thing should be breathing very, very well.

[Johnny Danger]

Originally Posted by insite

i am pretty sure the headers i'm using are sized right for my 3.4L. i am, however, obviously down on power compared w/ 996C2's and Cayman S's (they pull my on the back straight at road atlanta). since my headers are cheap ebay headers, they were my first suspect. i ran some calculations, though, and i'll be damned if they aren't a GREAT design for the 3.4L.

i just ordered a wideband o2 sensor so i can check to be sure the 996 tune is working right w/ my setup. with my intake & exhaust, this thing should be breathing very, very well.

What is the diameter of the primaries ?

[insite]

Originally Posted by Johnny Danger

What is the diameter of the primaries ?

42mm if i remember correctly

[BYprodriver]

Originally Posted by insite

42mm if i remember correctly

That's the size of my NHP manifold with sport cats at the inlet.

[Johnny Danger]

Originally Posted by insite

42mm if i remember correctly

That's small. I run 2.25 inches from the flange, through the primaries - all the way to the catback. The catback has 3 inch inlets and 3.5 outlets.

[BYprodriver]

Originally Posted by Johnny Danger

That's small. I run 2.25 inches from the flange, through the primaries - all the way to the catback. The catback has 3 inch inlets and 3.5 outlets.

Not the Hemi 'Cuda, the Boxster.

[Johnny Danger]

Originally Posted by BYprodriver

Not the Hemi 'Cuda, the Boxster.

That's my exhaust configuration - built and designed by M&M Exhaust in Germany who are the preeminent tuners for the Porsche Super Cup, Carrera Cup Deutschland, ADAC GT Masters, ALMS / LMS, VLN / BF Goodrich, FIA GT and Rallye Meistershaft race series. They also produce the current Cup S, Cup R and RSR exhausts for Weissach.

[BYprodriver]

Originally Posted by Johnny Danger

That's my exhaust configuration - built and designed by M&M Exhaust in Germany who are the preeminent tuners for the Porsche Super Cup, Carrera Cup Deutschland, ADAC GT Masters, ALMS / LMS, VLN / BF Goodrich, FIA GT and Rallye Meistershaft race series. They also produce the current Cup S, Cup R and RSR exhausts for Weissach.

That's WAY to big for street driving. That's killing your low rpm torque.