2005 seirra denali LQ9 6Liter

[herbison243]

I'm looking into a tune for my truck. I hope to gain some mileage and some power. My issue is I'm not sure whats the best way to get to my desired goal and the risks involved in each change that I make, any info would be greatly appreciated.

[smithers]

Hi, welcome.
Every build is different and requires different values in the ECM / TCM to be changed. There are several guides as to where to start in the stickies and plenty when using the search but no one is going to just give you answers, especially without stating what has been done, is it stock?
Millage and power come from making the engine more efficient, based on what has been done to it, if any. Just keep reading threads, utilizing the search button and reading the stickies.
http://www.hptuners.com/forum/showthread.php?t=4742


If its stock, the most common correction is to bring the PE and spark in line for starters.

[herbison243]

the truck is stock with the exception of a magnaflow exhaust that was on it when i got the truck.

[Sherminator]

A good flowing air intake will make both of those without requiring a tune. I recommend a sealed air box with a dryflow filter like a Volant, good flow, no oily air filter to deal with. Don't bother with headers, short tubes don't do anything, long tubes make more power and torque but can lose a bit on mileage in the colder climates. Work on the timing tables and being it's an LQ9, you should be running 91 octane or better to make the most of this engine. If you aren't, you will need to work on removing some timing so that it's not knocking.

[axekick]

The 6.0 responds very well to tuning in stock form. I like tuning them because they're bad ass and held back a lot from the factory. Sherminator is right, too. I've seen power gains by retarding the timing a couple degrees from the whole high octane table. The rest is just setting Power Enrichment to come in faster and at a good level (I like an EQ of 1.15). You really should make sure you're getting what you command by using a wideband. You can let it rev higher and shift at a higher RPM at wide open throttle. do all that and it will be night and day from the way it came.

[herbison243]

What kind of mpg gains do you think are possible? I currently get at best 20 MPG (us gal) oh the hwy and like at best 15 city.

[LSxpwrdZ]

I just tuned a 05 Denali the other day. Tranny wasn't healthy at all in it however. They pick up quite a bit from a tune. I've done quite a few truck's and SUV's and they all respond very very well to a good tune.

[Russ K]

You will need to install the Corvette 2-4 servo to fix the wot 1-2 slip shift. Also get rid of the PE delay.

Russ Kemp