re: pickuptruck.com review posted earlier. Here are my views, reflective of one who intends to power bomb from low to progressively higher levels with a target of approximately 400 RWHP.
• Air inlet redesigned to block hot engine air from entering, reducing the intake charge by 30 to 40 degrees.
Scotty air fixes this anyway, and the Proguard 7 or DD approach will also be very effective in this regard. Bombers will change the intake system anyway, so no envy here.
• Intake resonator re-engineered for increased airflow
this will probably reduce EGTs a tad, and may be an opportunity for the bombers to replace this on their trucks to I don't know. This was motivated by the NOx regulation which required a reduction in combustion temps to accomplish. mild to no envy
• Larger compressor on Holset turbocharger
A similar improvement for the 03-04 may be obtained by the Piersified turbo for small power upgrades. For all but small power improvements, a different turbo altogether will be required anyway, something like a DD or B1. So no envy here.
• Engine cooling improved with new fan assembly and mounting fan shroud to engine for more efficient airflow through radiator
We 03-04 guys will probably envy this, and wish for some after market solution to help engine cooling during sustained hard pulls with upgraded power.
• Upgraded intercooler
I wonder if the combination of this and the intake "resonator" (what does that mean?) is something special in some way. for the moderate bombers, the intercooler has seldom been problematic and I wonder what real benefit this provides. Additional EGT control of course, mandated by the NOx regulations (high combustion temps = NOx). So I'd say moderate to low envy here. I wonder if the 04. 5 will fit the 03-04?
• Upgraded exhaust valves
hmm. I'm sure we 03-04 guys have good valves, but we'll probably always wonder if the "updrade" here is due to swirl and combustion control, or durability. Are we sure this is an 04. 5 upgrade and not an 02-03 upgrade?
• Tailpipe increased to 4-inch diameter
the tailpipe is already 4-inch. what changed is the other side of the muff/CAT. Exhaust is easy to change on the 03-04s, particularly since there is no CAT (the removal of which could cause unwanted legal attention... ). definately no envy here
• Improved sealing and gasket materials
sounds good to me, but not sure what it means in terms of durabilty to the 03-04 engines. anyone know?
• Oil-change intervals are now 15,000 miles (vs. 7,500 for competition).
This is certainly not an 04. 5 change. this occured in 03.
• Switch to electronic control of wastegate
bummer for bombers. now if you put on an after market turbo, you have to either fool the ECM wastegate controller and temp sensors, or provide a more expensive after market turbo that includes the necessary sensors and controllable wastegate. definately no envy here; I'd rather have a "dumb" turbo.
• Upgrades to exhaust manifold
Certainly motivated by NOx reduction, to be sure, and not really important for the bombers because this is easily changed out to a 2 or 3 piece manifold anyway if necessary.
• Revised intake ports in cylinder head
• New piston bowl geometry
• Different spray pattern from injectors
these are all swirl and combustion control targeted at NOx reduction, not power or fuel efficiency. the latter may or may not have occured, but was not the motivating factor.
In general, what I see on the 04. 5 is motivated to reduce combustion temps and control NOx. Most of the efforts in this regard are already part of a bombers plan; the only exceptions being the intercooler and intake "resonator". its not clear to me if these represent weak spots that will frustrate moderate bombs. I suspect not.
to me, the most envious part of the 04. 5 changes are those relating to radiator and engine cooling. Why did they do this? From a theromodynamics standpoint I'm wondering if the new engine may have greater demands on the cooling system. think about it: Unless the new engine is more fuel efficient, you have the same overall heat dissipation requriements (energy lost in various forms versus energy to the wheels) But there is less heat going out the tailpipe (reduced combustion temps motivated by NOx control) yet more power going to the wheels. where does that energy go? the only other place it can go is the radiator.
for those intending to stay stock, I can't think of any disadvantage to the 04. 5 (the additional complexity is low, and far less than the competition). For the bombers, the 03-04 platform I claim is better because:
0. most of the 04. 5 air improvements are things that we will change anyway
1. the 04. 5 turbo will be more expensive/difficult to change
2. Removal of the 04. 5 CAT will be considered tampering with an emissions component (illegal)
3. the new regulations will likely mean tighter local inspections and greater risk that bombs won't be legal
4. The 03-04 fueling boxes have a greater chance of being street legal. they may never be, but they have a greater probability of obtaining such.
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