2008 GMC Envoy Denali

[Will L.]

Oh yeah, the 5 spokes look way better imo.

 

[ak diesel driver]

I had to look twice to notice the difference. Lol

 

[BIGR]

Both sets of wheels look nice, but the 5 spoke wheels look better to me. Run those in the summer and run the others in the winter.

It's great to have multiple sets of wheels for different seasons. I am lucky enough to have 2 different sets for both my Chevy trucks. On the worst looking wheels I run the most aggressive snow tires I could find. On the better looking wheels I run all season tires. Usually by now I have put my snow tires on, but I am holding out as long as I can. No big snow events yet that would scare me with the all season tires being on the truck. Weather man is talking a mixed snow and ice event next week, I might have break down and put the snow tires on the daily driver soon.

 

[n8in8or]

Oh yeah, the 5 spokes look way better imo.

I’m leaning towards them being my preference, but they don’t pop on the truck like I pictured in my head. I think the tires being dirty doesn’t help though.

I had to look twice to notice the difference. Lol

Ha! Yeah it isn’t the dramatic difference I thought it was going to be.

Both sets of wheels look nice, but the 5 spoke wheels look better to me. Run those in the summer and run the others in the winter.

It's great to have multiple sets of wheels for different seasons. I am lucky enough to have 2 different sets for both my Chevy trucks. On the worst looking wheels I run the most aggressive snow tires I could find. On the better looking wheels I run all season tires. Usually by now I have put my snow tires on, but I am holding out as long as I can. No big snow events yet that would scare me with the all season tires being on the truck. Weather man is talking a mixed snow and ice event next week, I might have break down and put the snow tires on the daily driver soon.

That’s how I do it, too. I wait as long as I can and then switch. A few years I even waited until the night of needing them - I would drive home from work on crappy roads with my summer tires and then swap to my winter set when I got home. Luckily I only live 5 minutes from work, so my exposure is pretty low.

 

[FellowTraveler]

5 Spoke is nice...

 

[n8in8or]

I've been dinking around with this thing the last couple weeks. Ever since I've built it, it didn't run like I've thought it should. I have HP Tuners and I've played with a couple small things (like disabling the torque converter unlock on decel), but I didn't feel confident enough to dig deeper and potentially do something wrong. Plus since it's my daily, I was just kind of over it.....just drive it and focus on other stuff. Well, when I had to use it to pull the trailer home when the trans lines blew on the dually, it pushed me over the edge. I've been unhappy with how the torque converter lockup strategy worked from the get-go, and lately I've noticed that a lot of the time the converter locks and then it unlocks for seemingly no reason - many times I've gone down the highway at 75+ mph with the converter unlocked, which sucks with 4.10 gears and a 3000-3200 stall. Towing the trailer home with this thing, I noticed that even on 55mph roads it was unlocking, which freaked me out because I was afraid of how hot the trans might get. That's it. I'm going to try to fix it.

I had read in some forums that this could be due to the cam I have in it making the computer think it's misfiring and then unlocking the converter. So I found another tune for a Trailblazer SS with a cam and copied the misfire portions of the tune to mine. VOILA!! It works like I've always wanted it to work!! This emboldened me. So next I copied over the transmission shift and TCC engage portions over to mine. WOW!! This thing is actually pretty fun to drive now! And it never made sense to me how the transmission tuning section of HP Tuners worked (it seemed way less intuitive than how it works in the US Shift controller I've been using in the Tahoe and now the dually), but now that I dabbled in it and saw the results, it started to make sense. Ok, let's see what else I can address...... the tuner said he had torque management disabled, but it still felt like it was doing things to me. I found some other tables in the tune that had torque management data in them, so I cleaned those up. WOW WOW!! This thing is a blast to drive now!!! I had some knock retard happening in the logs, so I stepped my fuel up from 87-89 and it got better. Then I went from 89-93 and it's pretty much gone. Nice. When I built it, I wanted to run on 87 for the lower cost, but I've realized that the performance of the truck is what I want, so time to make it optimized on premium.

I also noticed in a log that at 80 degrees outside, I was at 96% injector duty cycle......a little bit cooler/denser air and I'm totally tapped out. This won't do. So I contacted Fuel Injector Connection because I saw their name come up a lot in LS forums. They recommended their 42lb/hr (@43.5ps) injectors for me. They'll actually flow closer to 50 lb/hr at my 59psi system, which will support me up to 500 wheel horsepower, if I do enough to get there, yet still have perfect idle manners. And they have a lifetime warranty. Cool. So I installed the injectors and updated the tune with the data they provided to make them behave correctly. It's running a bit rich now, but that should be expected. This has forced me to move on to the next stage of the game - REAL tuning. I am now in the process of installing a wide-band O2 sensor so I can actually optimize my tune on the road. I'm excited to see the improvements I'll get from doing this. I hope to begin this later this week, once it's installed.

Later this fall, I'll be upgrading the exhaust. I still have the factory cat-back on it. It's been getting raspy, which I don't like. Plus the 2.75" tube is pinched pretty badly where it goes over the axle, so it's likely choking power in the upper rpm. A single 3.5" pipe is supposed to be zero restriction for 500 crank horsepower, so I decided to go with that. But I also want it to be quiet, so I chose a Walker RV muffler that has a straight-thru design, but a HUGE body. Hopefully it flows like gangbusters, but keeps it quiet. I'll also be adding a resonator at the end of the exhaust to further tame it.

I'm excited to FINALLY have this thing be the truck I hoped it would be from the start.

 

[n8in8or]

Here are some pics of the injectors I installed.



And another nagging thing: the Hawk rear brake pads I installed have always squeaked just driving around. It sounded like the pads were worn and the squealers were on, even though they weren’t. I was done with that. I searched on the TBSS Owners forum to see what others were running and found that a bunch of guys were happy with Brake Motive brakes off eBay, so I figured I’d give them a try. To my surprise, I recieved them the day after I ordered them AND they had Power Stop pads and rotors in the kit! I have them installed now along with some braided rear hoses and they work great PLUS no more squeal. One more nagging item on this truck is gone!!



Here’s current state for the O2 sensor install. I want to tuck the wiring in the dash. I’m also going to address one more nagging item while I’m at it: this had an aftermarket radio in it when I bought it. It’s a nice Pioneer touch screen unit, but I’ve had some speaker and steering wheel control issues. I’ve narrowed it down to the aftermarket module that allows the radio to communicate with the other vehicle stuff, so I’m also replacing that while I’m in there.

 

[ak diesel driver]

Good for you! It's always nice when things come together.

 

[Rockabillyrat]

That's awesome! Its amazing what GOOD tuning will do to an engine

 

[Duvall]

Your dually may get better fuel mileage than your daily driver.

 

[n8in8or]

Good for you! It's always nice when things come together.

Thanks! It feels dumb that it took so long to get it to this point, but I guess that’s what I get for mixing a project with a daily driver.

That's awesome! Its amazing what GOOD tuning will do to an engine

So true! Trans tuning as well, it makes a huge difference to how the whole vehicle behaves/performs

Your dually may get better fuel mileage than your daily driver.

Good possibility!

 

[MrMarty51]

Your gonna like that new Lambda O2 sensor.
I installed one on my 78 MGB when I was screwing with building an injection system for it. Finally went to twin SU carbs and installed that heated O2 sensor and a gauge.
After installing the gauge, took a trip over to Billings with the MG. 150 miles one way. The car used 3.2 gallons of fuel and four quarts of oil.
On the fuel, watching the gauge, I had to back out of the throttle on the steeper hills as the numbers would climb real close to burning holes in pistons.
On the oil consumption, I have never figured out where the oil is going. There is never any puddles under the engine or car, there is never any sign of oil spots on the rear of the bumper or trunk lid and there never seems to be any smoking out the exhaust.
Just one of those mysteries that will most likely get cleared up, if, someday I get the carbs rebuilt and functioning without risk of burning holes in pistons and can have someone drive it while I follow close behind and watch for smoking. From the car.

 

[Jaryd]

Nate, I thought you were trying to fix this truck to make it run better. And here you go putting Ford parts into this Chevy. Hell, it might get mad and never run again.

 

[Will L.]

Shoot. Might make it run better knowing ford is creeping in and it can be replaced!

 

[n8in8or]

Radio module is installed and now I have consistent function of the volume button on the steering wheel. I also have the majority of the console and center stack pieces cleaned and reinstalled. I just have to install the two panels under the steering column.



And most importantly the wide band O2 is wired and functioning. Tomorrow I should be tuning.

 

[MrMarty51]

This is going to get inneresting.

 

[n8in8or]

Got it all buttoned up today. I was initially going to have the MPVI module sitting in the glove box with an OBD port extension cable and hardwire the laptop charger into the truck, but decided to not do that. So instead I bundled all of the USB stuff under the panel under the dash and just had the USB-C cable sticking through and plug into the MPVI in the traditional location. Then I have a USB extension cable run through the center console, popping out through the rear cupholder. I can tuck the cable in there when not in use and stash the charger in the pocket in the back of the seat. Then when in use pull the cable out, plug in the charger and go. With this setup I can have the laptop in the front passenger seat or in the back seat if I have a passenger with me while I’m logging. It should work out well.



Today I did about a dozen MAF tunes done and got that dialed in pretty well. Then I did 3 speed density tunes. More tuning this week.

 

[n8in8or]

I'm still tuning......... I've learned that just my luck, my generation of ECM is more difficult to tune because it has a VIRTUAL Volumetric Efficiency table, so when you make changes to it, it does calculations to coefficients elsewhere in the tune and then to make the math work it will backwards update the VVE table, modifying the changes you just made. It's a lot of iterating to dial in the map. And since I was struggling, I redefined the boundaries of the zones in the table to help with those calculations......which basically started me all over again. I did that after the 24th iteration of the VVE tune. I'm now at the 29th iteration. Luckily it does seem like it's reacting a bit better now after the redefinitions, but man, this is a frustrating process. I really just want to be working on the IP swap on the dually, but I need to get this thing dialed in better before I do that. Good news is that Sunday I did some driving with one of the earlier tune iterations and it looks like my fuel economy has improved, so that's encouraging. Once I finally get the VVE dialed in, then I can start dialing in timing and then good things should start happening then.

 

[THEFERMANATOR]

I'm still tuning......... I've learned that just my luck, my generation of ECM is more difficult to tune because it has a VIRTUAL Volumetric Efficiency table, so when you make changes to it, it does calculations to coefficients elsewhere in the tune and then to make the math work it will backwards update the VVE table, modifying the changes you just made. It's a lot of iterating to dial in the map. And since I was struggling, I redefined the boundaries of the zones in the table to help with those calculations......which basically started me all over again. I did that after the 24th iteration of the VVE tune. I'm now at the 29th iteration. Luckily it does seem like it's reacting a bit better now after the redefinitions, but man, this is a frustrating process. I really just want to be working on the IP swap on the dually, but I need to get this thing dialed in better before I do that. Good news is that Sunday I did some driving with one of the earlier tune iterations and it looks like my fuel economy has improved, so that's encouraging. Once I finally get the VVE dialed in, then I can start dialing in timing and then good things should start happening then.

Welcome to gen 4 tuning, gen 3's did just what you told them.

 

[n8in8or]

Welcome to gen 4 tuning, gen 3's did just what you told them.

I'm learning this. Ugh.