Edelbrock intake differences

[StarlinerRon]

There is a real fine line at 2k rpm range. Throttle opening is VERY critical to economy. Try to ease up on the throttle until your speed just starts to decline. Close throttle on any downgrade. You're the computer now!
Cyclone3 is on the money !!!!!

Ron.

[winr1]

Do you have a vacuum gauge hooked up and if so, what are your readings in hi gear and OD at different mph/rpms ??

Loaded and unloaded ....

What carb is on your mill ??

Heads, valve size, ported ??

Complete cam specs ??

Exhaust ??

Just curious and keep a mental note of things such as this


Ricky.

[frnkeore]

Engine not meeting my needs:  Thought that comment might have been a joke but in case it wasn't...We have a 2002 Duramax we've used it to pull our fifth wheel through 40 of the lower 48.  And we really like it. If that somehow gets fubarred, I'd seriously consider finding an '80s or 90's crewcab to stick this 482 in and pull our camper around the country because I like it that much.  Really, I'm just puzzled why lower rpms didn't help mpg.  Thought intake was something to consider.  Now I'm thinking carb adjustment might benefit. 

Carb PV:  That's something I need to read up on...as well as get a new O2 sensor.  That's sounding like my first thing to check.

Sorry TJ but, it was this statement, that I was going by:

I'm a bit of an oddball not caring what happens above 4000...might have passed that once...rarely pass 3500.

If that's the case, your peak hp @ 5200 and peak torque @ 3700, would seem to be wasted hp, torque and gas.

[My427stang]

I see this as potentially too little gearing for use.  28% reduction of 4.11 is a 2.95 gear, pretty tall, especially depending on tire height.

In my Mustang with a 27.5 inch tall tire, I went from about 12 mpg to 14 mpg, and a much more comfortable drive when going from 3.70s to 4.11.  In town traffic was far better on fuel too.  I went from 2.36 to 2.63 final, but my car is a lot lighter and less frontal area than a truck.  I can't overdo how much nicer it was everywhere when I wasn't lugging and I also drive mine easy (until I don't LOL)

My truck does pretty well, but it is a 1:1 tranny 3.50 gear, 32 inch tall tire 4x4 with no overdrive.  I will someday adapt an OD, but when I do it will likely get 4.56s or so

I am not advocating a gear change for mileage alone, but a gear change to 4.56 would put you at 3.28 final in OD (assuming I have the .72 number correct) and may make the truck happier on OD when unloaded, and certainly happier when loaded.

Just a thought.

I'd also add that OEMs have added intermediate gears (more gears) in a tranny to get mileage, they haven't hobbled performance, even the smaller motors, so you could spend a thousand or more as an experiment on cam change, maybe more with a smaller runner head swap, intake swap, new pistons, etc,, but you don't see the gasser modern trucks do it, they add 8 or 10 speed trannies so they get mechanical advantage everywhere and OD on top.

[TJ]

Trying to respond to as many ideas as possible...

Appreciate the offer on the ported intake.  If (and that's a big IF) I swap intakes, I'll want to see what the out of box 390 does first.  At this time, I'm planning to stay with the RPM

Yeah, I'm definitely running a vacuum line through the firewall to watch vacuum at various scenarios.  Spent too much time reading on power valves and carb circuits last night...steep learning curve for me there.

There's been a few questions on the carb...it's a 780 Quick fuel. All I've done to it is switch to a manual choke primarily so I can manually set a fast idle for warming up.  Rest of the build is in the dyno section.

[/quote]

If that's the case, your peak hp @ 5200 and peak torque @ 3700, would seem to be wasted hp, torque and gas.
[/quote]

Maybe so.  I'm curious what moving the hp and torque peaks would do but no plans to find out. 
- We really like our duramax and have no plans to tune it or get a newer truck...it pulls our fiver well.  This 482 pulls our camper in overdrive with throttle left over and will out run the duramax up hills with the camper...without passing 3500 rpms.
- If the engine changes that move peaks to a lower rpm also result in less torque then I'll likely stay where I am. I'm at 580 lb ft now at 2500 rpms.  If the torque peak was moved to say 3000 rpms, would I have more or less than 580 lbft at 2500?
 -Then glancing at the current Ford 7.3 gasser, its torque and hp peaks are both 300 rpms higher than my 482.  And at 2500 rpms my 482 has more torque as a percentage of its peak than the new 7.3 gasser has.  My 482 makes 93% of its peak torque at 2500 rpms.  The 7.3 makes around 90% of its peak at 2500 rpms.
 -Even if I currently had a torque peak at say 2600, I'd be wondering what if the peak was at 3000 or 4000.


For gear changes, I've spent a lot of time calculating and theorizing.  Going to a 4.56 rear is something I haven't considered but will have to think about.    BTW, the gear vendor is 0.78 overdrive.