3" Exhaust L28E N/A

[S130Z]

I put the header on with the 2 inch collector and it is loud! As I was working I noticed the #3 exhaust port was stark white. I new I had a bad idle so im thinking the plug is not firing. I could feel and smell gas from the intake port so I know the injector is firing.

[1 fast z]

From my limited testing. I ran a 6-2-1 setup. NOT a cheapo MSA setup, but rather a long tube fairly tuned set, 1.625" Primarys, single 2.5" ex.. I ran 13.1 quarter mile time at 1300 feet elavation in my 280z. I then swapped a NISMO 1.875" setup, with a single 3" and gained 3 tenths in the quarter mile.

[Daeron]

Brian:

 

The 1/4" difference in primary diameter yields these cross sectional areas: 2.074 in^2 vs. 2.761in^2. Thats about a 25% difference in cross sectional area, obviously flow capacity wouldn't increase quite THAT much but its fairly significant nonetheless.

 

How much of the difference made in 1/4 mile times do you think likely due to the layout difference as opposed to this higher flow capacity? For reference, the primary sizes converted to metric are about 41.275 and 47.625 mm respectively.. I don't know what size exhaust valves you are using, and I am not trying to point you out as wrong by any means, just emphasizing the difference in primary size on your header change.

 

Edit:

I read that back through and even with my statement there at the end it still sounds like I am saying "!!!BUT NO!!! your exhaust was bigger and THATS why so you are teh n00b!!!!1!!" and that is NOT my intention. When I asked "how much difference..." I meant that question legitimately, not sarcastically..

[S130Z]

I just got back home from the exhaust shop and they did a decent job. The 2 1/2 inch pipe hey connected to the collector was kinda rough looking. It took them 2 hours to do the job and I just have a cherry bomb at the end. Its a lot more quiet than I thought it was gonna be. I will post up some pics when I can find my camera. And it only cost me $85.