[Joel5.0]

.... for bringing this back to the top, but when new facts and data of other people setups one has had the chance to help contribute, as little as it might be...... it has to be shared to prevent misinformation out there. The following is the experience of a person working on a '97 Mustang SC V6 setup, simply to make something different. His plans were a topic of discussion elsewhere and the focus was..... you guessed it right, the exhaust system. Since his build plan is staggered in phases, he installed the headers + 3" full dual exhaust to the stock EFI N/A 3.8L..... obviously, no dyno numbers were intended to be generated from that build step, but look at his experience regarding the misconceptions we usually read about, with the full 3" exhaust and the headers intended for the SC 3.8L setup......

it lost nothing, like I said I raced my brother's focus before and after (3.8s are stock slugs), he beat me everytime with stock exhaust from start off and I just barely started to catch up at 120km/h. After I got the exhuast on, I beat him from start off and just pulled away slowly all through the RPMs. Driving normal didn't change either and my MPG went up too.

The above was a reply to my direct questions regarding losses in torque and overall street performance, the MPG was an addition he shared on his own.

Now..... the above is just a single data point using a 100% stock 3.8L V6 EFI N/A engine with an automatic transmission. It's nothing to derive generic conclusions or BS, but that "exception to the rules" (if you want to tag it like so) alone, should be more than enough evidence to support the so called "techno babble"..... Otherwise......

1. How is that interim setup performing better with such a reduction of the scavenging with stock V6 heads? .... or,
2. How is that interim setup performing better with such a theoretical reduction in the exhaust flow?