Little background on my truck is that it is completely stock as I've been focusing on maintenance sense buying it a few months back. I plan on building it up as a offroad/camping rig but now i'm having doubts and seeking advice and opinions.

I'm mostly seeking the opinions of those who have experience of driving at very high elevations simply because the performance and power effect is probably like comparing apples to oranges for those who drive at or close to sea level.

I love this truck and its capabilities but every time I drive out to the mountains I seriously hate how slow, laggy and underpowered it is. I feel like I get passed by every car/truck on the road and many times have the peddle pined to the floor. I know its not supposed to be fast or resemble a race car but when I drive out the mountains I get a the feeling that this vehical is an absolute dog and completely underpowered and I consider selling it.

By the way, I do all the normal stuff like O/D off and ECT on.

So this leads me to the discussion. Obviously ive read and talked with members about the vast improvement a supercharger makes especially at higher elevations but I wonder if it will be enough of an improvement in order for me to completely change the way I feel with driving this truck in the mountains. Especially when/if I had a lot of extra weight and larger (33")
heavier tires. I know people say the supercharger makes a huge difference but really is it enough to change the way I feel about this extremely laggy, underpowered truck?

Next would be how would the V6 supercharged and perhaps upgraded pulley compare to a V8 4th gen in regards to power and feel of driving at high elevation.

SuperCharger is more for HP. At those elevations and what is sounding like you're trying to do, torque is more important. The V8 4th gen makes 320 lb/ft of torque. I think the V8 would fit your needs more.

If money were not an issue and I didnt have to do the work, I would say V8 all day long!

I don't plan on or am discussing a swap but thinking about either supercharging my 3rd gen or selling it and buying a V8 4th gen.

Well you make about 155hp at Denvers elevation, with a supercharger you can boost your engine to stock and then past, so you will easily see a 75hp+ gain which is 50% more power.

***Edited post to correct info***

From some info ive read on speedys blog Project SportRunner he had his dyno'd with 7th injector and 2.2 pulley. He put down 240rwhp and 260rwtq. Assuming 20% drivetrain loss that's 288hp and 312tq at the crank.

Now to compare those numbers to a stock V8 4th gen you'd have 235hp and 320tq for 2003-2004 models with non VVT-I. 2005-2009 offer 270hp and 330tq. Both V8 models offer the 5 speed auto trans which is probably much better than the more sluggish 4 speed auto in the 3rd gen.

so all seems somewhat comparable according to just numbers, although 5 speed automatic probably makes quite a difference.

3.4L V6 supercharged with urd 7th injector and 2.2 pulley
288hp and 312tq at the crank - 240rwhp and 260rwtq at the wheels

4.7L V8 stock 2003-2004
235hp and 320tq at the crank - 188rwhp and 256rwtq at the wheels

4.7L V8 stock 2005-2009 VVT-i
270hp and 330tq at the crank - 216rwhp and 264rwtq at the wheels

Colorado 2002 Sport Edition w/Supercharger.
It makes a big difference going up the hills to the mountains. I have no problem keeping a constant top speed from the base to the top of each hill, even when fully loaded with people, dogs and gear. And if I keep my foot out of it too much, the mileage (17 - 19) is pretty good.

A 4th Gen is larger and weighs more than a 3rd Gen...and also has lower ground clearance.

I had a 4th Gen and now have a 3rd Gen. I'll take my '02 any day!

Hmm...I would think a supercharger would be better. The loss of power at high elevations is due to a lower concentration of oxygen in the air. Superchargers increase the density of oxygen that enters the engine. So my thought is a S/C is better?

Except the 4.7 4runners have f/t awd so it wouldn't be rwhp

They increase the air density, but if you climb elevation they don't increase even more to compensate since the pulley doesn't actively change diameter (to change SC speed and thus boost). That's what I really want to see, is a "smart pulley" that can actively change sizes to give more boost when you want it, either in an rpm range or so you get the same horsepower regardless of altitude.

True. I didn't think about that when doing my calculations. With rear wheel drive you can assume approx. 20% drivetrain loss for rwhp numbers. What would the approx. drivetrain loss be for fulltime awd?

I live in the mountains and have never once thought my bone stock v6 automatic ever lacked any power even on the climbs. Sure, there are vehicles on steep grades that can accelerate faster than me, but I can maintain the speed limit.

But if it was between a v8 or v6 supercharged, I would rather have the v8 myself.

2JZ swap!

However yes it does get irritating when you are trying to climb a hill (mountain) with a full load as you struggle to keep up.

At what elevation do you live and frequently drive though?

I can tell you that I live at about 5500 ft and around town it drives fine and doesn't bother me at all. Once I get to about 7000+ and get on steady gradual climbs my trucks starts dropping speed fast and I have to floor the peddle patiently waiting for what feels like eternity to reach the speed limit. Many times I'm driving "on road" at 10,000+ feet. That's a huge difference compared to North Carolina's 5k-6.5k ft elevations.

so you have 33's now?
if that's the case, re-gearing to stock would help, possibly would even be enough to satisfy you.

even running the SC with 33's, you'll still the under geared.