CHRGDUP Denali
 

Been on here a while and haven't posted much so here is my official build thread.

Truck is a 2008 GMC Sierra Denali 2wd 6.2l/6l80e. Bought it stock a few years back and have gone back and forth with plans for it. I original lifted it (I know, lifted 2wd :bang: ) but eventually put it back down and put money towards supercharging it. Truck is currently bone stock (yes, no headers, cai, etc.) with a supercharger. Magnuson TVS1900, only upgrade I've done for it is the fuel pump, I used a flex fuel pump. Runs great but of course I have future plans for supporting mods. I will update as mods continue. Goal is to have truck for daily driving and towing that will put a beating on camaros, mustangs, etc ... which I have somewhat already accomplished. stay tuned.

Nice truck! What kind of power did it make with just the supercharger on the 6.2?

thanks! I haven't dyno'd it. I went to the strip yesterday to get a clue of where it's at and ran 12.98 @ 104.87.

Damn....I need a blower, nice time!

thanks and you definitely do! I never want to drive another vehicle without boost.

How much does she weigh?

google says curb weight is around 5200

You should have around 500 rwhp horsepower.

yea I was thinking mid 400s. I think I'll definitely be at 500 when I do supporting mods. exhaust stock manifolds are choking this blower. cam, vvt delete, ported ls3 TB, headers, injectors etc are on the list.

I think you'd be surprised how little the exhaust manifolds itself matter. It's more about getting the air into the supercharger and through the cylinder heads. There is a reason why CTS-V's, Corvettes and Camaro's made the power they do with cast steel manifolds.

so my stock air box and tb are a bigger set back?

Those manifolds were designed to flow a lot more than a set of truck manifolds that were designed for torque. He has a blower, torque isn't a problem anymore. When I added my kooks it unlocked an instant 30 or so rwhp. You will make more power with less boost, if you can't get the air out that your shoving into the motor you will just make heat. Get a set of long tubes and a y pipe and you won't believe how responsive it becomes! It really woke my truck up, besides the blower it's by far the best mod so far...

that is the plan, just wanted to hear his explanation. me and my dad are actually going to build an equal length exhaust for it but have to wait until I lower it and do 2 piece driveshaft swap to make sure the exhaust will clear everything.

Super Chevy did a test with a 427 stroker with a 2.9 kenne bell blower on it, they did both tests stock manifolds and long tubes on a engine dyno. The end results between the two was like 20hp and 5-6 ft/lbs just from the header swap alone. Of course results vary with application.

If someone just adds headers to an already supercharged engine they shouldn't be expecting the world from them. The scavenging effect of long-tube headers does help but someone shouldn't expect to see 30-50whp everytime.

There is likely another cause if you did see such an increase, like clogged cats, restricted exhaust past the manifold.

It's just why I commented and said they aren't the biggest player in the horsepower race. There can be more gain in other parts in the engine like camshaft, cylinder heads, compression ratio and tuning.

that's interesting. 20hp is still 20hp though. did they run different exhaust behind headers compared to stock manifolds or kept same exhaust to strictly compare manifold vs headers? I'll be doing longtubes but will also be deleting cats and replacing stock muffler with straight through muffler at the same time. not sure exactly what the experiment entailed. on another subject, I'd like to know your opinion on vvt vs non-vvt cams for my application. already had a guy on here spec me a mild non-vvt cam that I haven't ordered yet but have really been considering keeping it lately.

Intake first, then headers. I put Kooks headers with performance cats on my stock truck. The stock airbox was definitely a restriction. Personally what I did was cut a hole in the factory lower airbox behind the headlight. I still have the factory catback exhaust.

Intake isn't so easy with a Maggie...

You already have an intake tube, cut the lower box open or spend money. You’ll spend time and money on headers, but not do a free mod like I suggested? You’re funny! Lol

I cut holes in the air box of my old truck. I can do that free mod you suggested for now if I wanted, but I will eventually be doing otherwise anyways. appreciate the suggestion.

I hole sawed my stock air box already. My tuner wanted me to just replace the filter box and keep the Maggie tube. Fire up your 2.5" hole saw!

this truck actually had a cheesy cai when I bought it. traded someone for stock air box after I put the maggie on. imma build a 4" cai later on.

finally lowered the truck today. also installed 2 piece driveshaft and helper bags.

Nice setup, How did you lower the rear? Also how well do the air bags help out?

thanks. rear is lowered with mcgaughys flip kit to 7". I run enough air to make it ride level and will be adding a .5" lift shackle to be able to run less air in bags and stay level. bags work great though, actually pulled our boat back into the shop right after installing bags with no issues at all. main reason I put bags, besides towing, is to keep from bottoming out on frame since I didn't notch it. works great so far.

relocated helper bag valve from holding up my license plate on one side to now in the bumper pocket that goes to spare tire, since I don't carry a spare. using mcgaughys helper bag kit and love it so far.

got some goodies. speed engineering 1 7/8 lt headers, aem wideband and boost gauges (fuel pressure gauge on the way), and currently painting pillar triple gauge mount to match interior using SEM 15143 Sandstone. it's not perfect but pretty close.

Why no AEM with can-bus connectivity?

not sure what that is. is that where you can log data and stuff like that? I chose these specific gauges because they are very simple and look similar to my factory gauges when put together with black backing and silver trim. didn't want anything digital or flashy

The NNBS or newer trucks can use the can-bus wiring system through the OBD-2 port with the certain AEM wideband for logging and tuning if you wanted too. HP Tuners and EFI live I believe can both use it but I guess if someone doesn't do their own tuning it's not so much of a need then. Plus they only come in the red digital display.

oh that's cool, but you're right. I personally would have no use for that.

finally got off the caddy wheels. OEM 20s on 275/55s. swapping for GMC center caps today.

better pics on the new wheels

Nice.....Huge Improvement!

thanks, I agree !

Looks much better!!!!

thanks. love these wheels

got the gauges mounted and wires pulled through today, will finish them up soon. color doesn't look too bad.

here's a video from today. stock exhaust still. 20mph punch

Uncork it brother...

https://cimg8.ibsrv.net/gimg/www.per...e5e7ebd556.jpg
I have headers and mufflers at the house. waiting on vbands, mandrel pieces, tips, and x pipe.