SicSE
Veteran CEG'er
This is a power output comparison. Open SHM headers vs. open SHM y-pipe, vs. 2.5" exhaust with no catalytic converter.
The PCM had trouble adjusting A/F to suit the open headers, even after over an hour of idling, driving the dyno rollers & general engine revving. But since the A/F stabilized before peak hp/tq, I consider the results dependable to use for comparison.
A few A/F graphs go stupid-lean at the end because the sniffer was blown out of the header and/or tail pipe.
I had to drop the smoothing down to 3 for the individual tests because there is a spike and break in the torque curve in an open header run that shows it's peak torque @ 212.
So without further ado...
Open headers
Open y-pipe
Test pipe exhaust
More charts to come...
The PCM had trouble adjusting A/F to suit the open headers, even after over an hour of idling, driving the dyno rollers & general engine revving. But since the A/F stabilized before peak hp/tq, I consider the results dependable to use for comparison.
A few A/F graphs go stupid-lean at the end because the sniffer was blown out of the header and/or tail pipe.
I had to drop the smoothing down to 3 for the individual tests because there is a spike and break in the torque curve in an open header run that shows it's peak torque @ 212.
So without further ado...
Open headers
Open y-pipe
Test pipe exhaust
More charts to come...