2008 Denali Goes Much Much Faster!

[Smokymance]

K ddsl...you are correct...id like to keep it quiet and not too loud...

Blower future plans? i never know...i say no now, but later on i want to FI...

Thats what happened with my last vehicle

 

[K_ddsl]

What were the dyno numbers? I couldn't tell by the vid?

Remember this is with Justin's initial tune.
I am hoping he can tweak in a few more ponies for me.

 

[JennaBear]

Fourth gear is WAY TOO HIGH- especially on a DynoJet. It revs out too fast, probably around 2 secs rather than 10 secs.

If you can, I would recommend you trying to do it in 3rd- as it stands you risk blowing your driveshaft.

 

[K_ddsl]

I thought 4th was the standard gear for running the 6L80...
When I get the final tune installed I will run it again in 3rd and in 4th just to have a base comparo as I do not have 3rd gear runs to compare against!

 

[JennaBear]

Just be aware that the risk is there with a high gear.

 

[K_ddsl]

Thanks for the heads up. One last 4th gear pull with the final tune and that's it.

 

[Denali0229]

350? What does that equate to in real real wheel horse power? I thought there is a loss or gain from the dyno. I thought it would be over 400 with the mods you have and the truck coming with 380 stock.

 

[JennaBear]

The 403HP stock from the manufacturer is at the crank (for Denali/XL, Escalade and SLT Sierra).

 

[K_ddsl]

As Jenna mentioned, the numbers you are quoting are crank hp.
A stock 2008 Denali would dyno around 280 at the wheels on this dyno with the way the guy has it set up. 2009 up Denali is slightly higher as GM increased output to 403 crank.
Achieving 350 awhp is a jump of about 70 horsepower at the wheels.
This is not bad at all. We will see if we can squeeze out a few more hp with the final tune.

 

[Fast55]

There isn't a single mfg. that gives HP ratings "at the tires". Every number is crank horsepower, always. Depending on drivetrain (2WD, 4WD, auto, manual, etc), the drivetrain "loss" is usually given to be 15-20%. For all the cars/trucks I've built (usually power robbing automatics) I use 18%. That means the truck is around 420-430HP. I would have expected more given my tuned but otherwise stock 6.2 made 340 RWHP, but what's most important is to look at the difference between stock RWHP and what the modded RWHP is, especially since there are so many variables between dynos, correction factors, temperature, humidity, gas, etc.

 

[K_ddsl]

Absolutely. Remember also you quoted rwhp. Mine is awhp.
Much higher parasitic loses in an all wheel drive car between crank and wheels than a rwd.
Like I mentioned, stock 2008 makes about 280 awhp on this dyno in similar conditions.

 

[K_ddsl]

Fast what did your 6.2 dyno at before the tune?

 

[Denali0229]

Jeez, I'm lost in all this crank, drivetrain, HP talk. All I know is my truck is much faster with a BB tune and intake. It would be really hard to go back to stock after feeling the power the truck has now. BTW, I love the way your truck sounds. I doubt I'll do anymore performance mods at this point. Maybe a new muffler much later down the road. I'm gonna start working on new wheels and a system and hopefully I'm done putting money in this thing :0)

 

[Smokymance]

You guys have any thoughts on LPP headers? i hear good things online, yet not alot of people have them...

any thoughts?

http://lpparts.com/store/page7.html

 

[K_ddsl]

I have no direct experience with them.

I ran a google search and checked a few threads out. From what I've read they seem good. Super cheap as well.

I just wonder if the age old saying of you get what you pay for applies in this case.

The industry leaders such as ARH, Kooks, Dynatech and SS works all seem to be around the same price.

These are roughly one third.

Doesn't mean they are no good though...

 

[Smokymance]

Agree with you totally...i email them and got a very quick turn around...

They told me exactly what to expect during installation and what will and wont work, which in this case is the Y-pipe...i will also prob have to do a catted application as i dont want it loud

 

[johnsoex]

I had lt headers with no cats and a magnaflow and it was way too loud. Changed to borla and it was better but still loud. I added another borla and a 14 inch manga flow resonator and now it's quiet, very quiet until I get on it and then it opens up nicely.

Pacesetter coated Lt headers, y pipe, resonator, single in single out to single in dual out after the pass rear wheel all thru 3 inch pipe is a good way to go if you want flow but not the loud sound.

 

[K_ddsl]

Where did you find space to put two mufflers and a resonator?
Do you have pics of the setup?

 

[johnsoex]

Here are a few pics. Sorry for the quality. Dropped 2/4 so its hard to get under there.

There's not much tubing. Lt headers into the y, then apprx 3 inches of pipe (just enough for the wide band bung) into 14 inch resonator, which is welded right onto the first borla, 2 inches of pipe then into the second borla, then duals over the axel turned out to the side.

 

[felixgun]

View attachment 14935View attachment 14936View attachment 14937View attachment 14938

Here are a few pics. Sorry for the quality. Dropped 2/4 so its hard to get under there.

There's not much tubing. Lt headers into the y, then apprx 3 inches of pipe (just enough for the wide band bung) into 14 inch resonator, which is welded right onto the first borla, 2 inches of pipe then into the second borla, then duals over the axel turned out to the side.

Wow what a great idea to make it a bit more quite. Looks good underneath too.