The 04.0

[ARARAR]

The 04.0 on Sale

I have been pretty happy w/my 98. 5 since I made all the upgrades. Now I'm seeing all these specials for the 04's the're trying to dump now that the 04. 5's are in. I haven't been on the forum for quite a while so I'm not familiar with any of the upgrades (if any) they've made lately; especially to the auto trannys, hp, and smog requirements for the calif. models. If I decide to buy a new truck I'd like to be a little more informed. Some of the deals the're offering are pretty inviting, so any input you guys might give me is appreciated.

 

[bmoeller]

Originally posted by rbattelle

In the list of changes:



• Air inlet redesigned to block hot engine air from entering, reducing the intake charge by 30 to 40 degrees.

• Intake resonator re-engineered for increased airflow

• Larger compressor on Holset turbocharger

• Engine cooling improved with new fan assembly and mounting fan shroud to engine for more efficient airflow through radiator

• Upgraded intercooler

• Upgraded exhaust valves

• Tailpipe increased to 4-inch diameter

• Improved sealing and gasket materials

• Oil-change intervals are now 15,000 miles (vs. 7,500 for competition).

• Holset turbocharger gets bigger compression side

• Switch to electronic control of wastegate

• Upgrades to exhaust manifold

• Revised intake ports in cylinder head

• New piston bowl geometry

• Different spray pattern from injectors



I'm curious about the piston bowl geometry changes, upgraded exhaust valves, and different spray pattern from the injectors. The article also claims there is to cat on the 04. 5 trucks... I thought there was one on the 04 trucks?