|
Intake and Exhaust
I believe that's usually the case, but this engine needs to rev efficiently in order to move a lot of weight in the city. I am going to try both cold and warm air out over time.
On the exhaust, the magnaflow exhaust pipe isn't any bigger, just the tail pipe. Stock exhaust is 2 1/2 inch back to tailpipe which is 2 1/4. Magnaflow is 2 1/2 all the way back. The stock size smaller pipe should keep the scavanging velocity up for low end torque, but the freer flowing muffler allow more flow when needed for higher end power production. I also wonder if the freer flowing muffler may improve bottom end torque because the effective exhaust length is longer since the exhaust pulses travel all the way to the end of the exhaust more easily. I did the same thing on the Ford 1.9, kept the stock pipe size, but upgraded to the GT muffler (direct bolt in). The engine pulls very nicely at low rpm and makes much better power than stock when revving out. The 1.9 does bout 27.5 to 29 mpg in the city with no special driving techniques. In fact I want to see if I can get the auto trans into overdrive sooner because the low end torque is so good. Currently it goes into overdrive and locks up at about 37 MPH and can still accelerate strongly at those speeds. This should hep city mpg. The Jeep drops into overdrive about 30mph and tugs along all that weight at about 1200 rpm.
|