The Woof's 2o11 Colorado

I like the look of the Colorado, but the fuel mileage and interior kept me away. What are you getting for mileage? Is your tune for 87 octane or 92+?

I have a 2005 Colorado crew cab, Z71, 5 cylinder. I can get around 20 mpg on the highway and that's using 87

Iusedtobefast wrote: I have a 2005 Colorado crew cab, Z71, 5 cylinder. I can get around 20 mpg on the highway and that's using 87

Auto, I assume?

I just did the conversion, and it looks like I'm averaging between 26 and 30 MPG

I haven't done the tune yet, but the stock tune has two timing maps. It defaults to the advanced (timing) map on start up, then reverts back to the standard map after it detects three knock events. I run premium to stay on the advanced map all the time. I haven't noticed a difference in fuel economy, but it makes a significant difference in power.

I drive it pretty aggressively.

Woof, is that to a US gallon, or Imperial ?

I originally posted it in L/100 km, but went back and changed that to US gallon.

In reply to Ranger50: Yes auto. I would think it would be a little better than it is.

26-30 Combined or just hwy? that sounds pretty good for one of these trucks.

Mostly hwy. I could probably get just as good with a v6 or 8, and have more fun to boot.

In reply to Gearheadotaku:

Combined. I thought it was pretty good.

I didn't get a chance to swap in the 4.10's and locker. When I pulled the pinion out, there was a light band of wear on the bearing closest to the gear, so rather than risk a noisy rearend, I picked up a rebuild kit for $80, and hopefully will get a chance next week. I'm anxious to see what it's like with more gear, and to see how the locker does through the winter.

Once this is done, it's time for the tune

Those were pre-tune numbers? Now I'm really interested....Is your current gear 3.73 or 3.42?

Yes. Pre-tune. The header and exhaust made a difference in power, but didn't seem to affect fuel economy. Maybe if I drove it easier they would have. 3.73 gear is stock, and a better choice than 3.42, IMO. My last one had 3.42's. The fuel economy was no better, and it always felt like it wanted more gear.

So after a ridiculously cold winter, I finally got back to this, and put the 4.10 and locker in it. It was a straightforward install. Used the same spacers from the 3.73 set, and lash measured out to .009" (.006-.010" spec), with full contact. I figured the gear change would make a big difference, and was hoping it would be in a positive way. 4.10 could be too much gear for a daily driver. Well, I was wrong again. The difference was subtle, but so far it's all positive. It pulls better, no longer lugs, and doesn't seem to always be in between gears like before. I wish this was the ratio it came with from the factory. As for the locker, I've never had one before, and wondered how it would work. Except for now having traction where I used to spin before, it's seamless. You'd never know it's there.

The main reason I did it was for towing. I don't have a race for a few weeks now, so I won't get the chance to see how it is. It looks like it will put an end to the annoying upshift/downshift when I get into a strong headwind, or hilly area, and pull easier at the same time.

I drove a dark blue 5.3 ext cab 2wd at work the other day. Super cool, I love how small it is but is functional and has that beast motor. I bet with a little work you could smoke a Lightning or SRT10 Ram truck with it. Not that the SRT10 is anything to write home about.

Your truck looks great! Keep it coming! This isn't the typical build for GRM, I'm enjoying it!

A few days before I did the gear/locker swap, I was turning around and backed onto the grass in front of my shop. With all the rain lately, when I went to go forward, it just spun, and started sinking. I had to remove the trailer and rock it out. A week after the swap, I accidentally did the same thing. It started to spin, then hooked, and walked right out. Awesome. Fuel economy over two tanks doesn't seem to be much, if any different with the 4.10's.

I spent the better part of the day installing sound deadener to try and fix some of the droning, and resonance in the cab. It's a base model truck, so there's not much in the way of sound deadening. This isn't mine. I wasn't smart enough to take pics while I was doing it, but it is a Colorado. Not much in the way of insulation here. I pretty much did this, but stopped at after the floor hump at the back because I was too lazy to take the seats out, and wasn't sure if I would have enough material.

I bought a 50' roll of b-quiet . I've never done this, but it was pretty easy. Did the back wall, some of the floor, and the doors inside and out. While I was at it, I did a little crossover and speaker tuning. Last week I put a Clarion HU in, and wasn't happy with the sound. Much better now, and the truck goes down the road a lot quieter.

Since I hadn't changed the muffler in a few months, I decided it was time, and put a Cherry bomb Elite on. Sounds a lot better than that super turbo, but since the header install, nothing really sounds great. I think I'll put a single chamber muffler up front as a resonator and see if that helps.

http://youtu.be/hFDG0YX7gY0

So it's been about 4 months since I've updated this. In that time I finished up the sound deadener installation, installed yet another muffler, eliminated the stock resonator box from the intake, installed an a Clarion head unit, and finally got around to tuning it.

The deadener made a difference in road noise, and bass from the DIY component speakers I put together. It wasn't a huge difference, but the truck wasn't really noisy to begin with. The Cherrybomb Elite sound good, but was a little too loud still, so I opted for a Flowmaster 70 series. I was never fan of FM before, but they really do make the 4 cylinder in these trucks sound good.

The tune was the icing on the cake. After all the mods, it ran great, but there were still a few hiccups in the way it accelerated, and cruised. The highlights were to recalibrate the MAF, dump the torque management, correct the speedo due to the 4.10 gear install, maximize the timing for premium fuel (not much work there, GM pretty much nailed it) move the variable valve timing events, increase the rev limiter to 6500, and make the throttle more linear. He also found that we were able to add a little timing at cruise.

What a huge difference overall. The truck ran great before, but the tune was just more better everywhere It's way smoother and pulls much harder from idle to redline. It feels now like a motor that wants to rev, as opposed to the low RPM truck motor it felt like before.

I managed to find a set of 235 65 16 tires on clear out at a local Honda delership, so those will go on before winter, but so far I think I'm just about done with this project. Once they're installed, I'll see how it sits, and decide whether or not to install the 3" lowering blocks I picked up from the Colorado forum. It still is a little high in the rear, so we'll see how it looks. I can always machine them down to 2 1/2", or just leave the 2" blocks in there.

Just curious, what are you planning on towing with it?

Have a video for sound on the new flowmasters? I've watched this thread closely for muffler advice...

No, but ff you look at my exhaust videos, it sound very similar to the FM50/CB Elite, but a little deeper in tone. The problem with those other mufflers is that once I put the header on, and that precat was gone, the exhaust just got too loud. The 70 was the biggest muffler I could fit in there of that style, and I'm very happy with it. Good sound, not loud, and no noise or droning on the highway.

I completed an experiment yesterday, driving like a normal person for a full tank, just to see what kind of fuel economy I would get. Nothing special, just little aggression, and minimal speeding. There was 120km (about 75miles) of towing my bike and trailer to the races, about 1200 lbs. in that tank.

I got 8.4 l/100 km, or 34 MPG imperial, or 28 MPG US.

Not bad for a truck that size, with all those mods.

What will I be towing with it? My bikes, and if my wife gets her way, a small travel trailer, likely an Rpod.

great build thread

Thanks for the updates, very surprised at the fuel mileage you are getting.

Something I forgot to mention, my son was moving yesterday, and borrowed the truck. He hasn't driven it since I've completed the mods. I told him what I'd done, and suggested he run it through the gears, and give me his honest impression. I'm pretty sure he's wrong, but he said it would probably smoke his modded RSX.