Where is the best place to gain power from the L86/6.2L truck motor?

[99LS1SS]

I want to try to squeak out some more power from my truck if I can. What are the the best bang for the buck changes on these motors? The Main Spark Advance seems to be set fairly high out of the gate so I'm not sure if that is a good starting spot or not.

2016 GMC Sierra 6.2 A8 stock - My Truck.hpt

[GHuggins]

There are extremely nice gains to be had down low on one of these with timing, fueling and a cold air intake... I typically see something around 50 to 60hp below 4000 rpms and only around 20 to 30 hp at peak... Nice tq gains down low with some these minor adjustments too - not to mention the fuel economy gains - I had one guy reporting 27.5mpg out of a 4wd 4door short bed on the highway... You just have to make sure you don't overshoot the timing down low - you'll lose a hefty chunk of the gains if you do...

[Jay@HAP]

I've seen 30+rhwp gains by just bolting on headers and y pipe. We do R&D testing with a very well known header manufacturer. 1 3/4 and 1 7/8 headers were within 5hp/5ft lbs of each other.

[BADFNZ]

There are extremely nice gains to be had down low on one of these with timing, fueling and a cold air intake... I typically see something around 50 to 60hp below 4000 rpms and only around 20 to 30 hp at peak... Nice tq gains down low with some these minor adjustments too - not to mention the fuel economy gains - I had one guy reporting 27.5mpg out of a 4wd 4door short bed on the highway... You just have to make sure you don't overshoot the timing down low - you'll lose a hefty chunk of the gains if you do...

How much timing are you generally adding down low to see these gains? I've slowly been adding timing advance down low and started getting some pretty significant KR when I added more than 3-4 degrees at certain RPMs. Granted, this is on a 5.3L and not a 6.2L, but I'm assuming the timing curves aren't that different. This is on 87 octane for now. Do you tune for a higher octane?

[GHuggins]

Pretty sure this was an 87 octane tune as it's a work truck... It's one of them reporting up to 27.5mpg... Like I said - there's other places in the tune that corresponds with this...

[[email protected]]

Which timing would you be referring too, cam timing I assume? Is cam timing something that can be adjusted with tuner?

[Ben Charles]

Which timing would you be referring too, cam timing I assume? Is cam timing something that can be adjusted with tuner?

Yes cam timing can be adjusted

[[email protected]]

What! no way, how do you do that? I have seen the variable cam tab, but I need to zero all them out since I replaced the cam and installed reg sprocket and did away with phaser. Are there other area's with the tuner that can affect cam timing?

[GHuggins]

I was referring to ignition timing, but on these there are also cam timing and injection timing to name a couple more... Then you have really detuned throttle settings which will get you a lot in the lower rpms... DD for throttle aggressiveness - don't really recommend messing with that too much if any...

[RRLs3]

Does anyone have a tune I could look at for a 2016 Sierra 6.2? Looking to remove speed limiter and get some gains. Only mods are cold air intake, and muffler nothing major.

[jpierro79]

Ok let?s be honest if you change the cam and headers will be your largest gains for money. Other than a supercharger. No tune will get you large gains. Not stock and they don?t flow enough to really out flow stock intake like a zl1 persay. Get headers wideband intake retune legit 50 whp. Cheapest way. Gm did a pretty good job tuning newer cars. Stock without mods don?t expect much not even on e85

[Ben Charles]

I make awesome gains on stock vehicles, not sure what you?re seeing, but gains just as much as they always have

[1slow1500]

I thought the best "gain" was it the trans in these trucks. If you are asking hp/torque then that is another story. But the trucks I drove that the trans was tuned move out. I left my trans untouched and started adding boost, just to quickly see the truck not like it. I'm sure anyone could get more aggressive with stock tune on a stock engine and see good gains. I have hear great gains from E85 and tunes.

[castorjames]

just did a 2015 one, completely stock, didnt even needed much modifications, i just leaned PE, added like 2 dgre over stock,modified base corrections, substancial gains from start to end of the pull,30rwhp gains with those basics, didnt shoot for more it is a work truck and max power wasnt important, but i noticed great gains with little modifications

[Crysis]

Ive never tune a vehicle that liked being leaner ive seen like 20 hp gain just from going to a 13.0 to a 11.5 on boosted vehicles

[castorjames]

Ive never tune a vehicle that liked being leaner ive seen like 20 hp gain just from going to a 13.0 to a 11.5 on boosted vehicles

i mean truck was stock not FI, fuel in some spots where at 11.2 11.5 AFR,, changued to 12.9-13.2, timing was low on the stock tune(15-17, changued to 22-19, i have dyno to confirm, good gains throught the pull and 30WHP,

attached is the log of the stock tune pull

[jpierro79]

Intake cam headers use a wideband and for the money you will see consistents gains throughout. People forget alot a car with 650 whp at 6500 can be outrun by a car with a 600 whp but much larger power band. Dont think in terms of max hp or tq gains but gains throughout. Usable power. w here can you gain the most usable power throughout. Cam being the most expensive but most effective paired with headers. Intake being the cheapest but obviously the least usable as it only comes into effect on top rpm which becomes almost unusable. E85 flex fuel is least cost but remember your going to be going through fuel like water. Again not peak gains think of fattening your powerband

[Fostang331]

Pretty sure this was an 87 octane tune as it's a work truck... It's one of them reporting up to 27.5mpg... Like I said - there's other places in the tune that corresponds with this...

Any chance you would share the whole tune file? I am working on a 2017 Yukon 6.2 8 speed.

[lucas287]

Any chance you would share the whole tune file? I am working on a 2017 Yukon 6.2 8 speed.

GHuggins hasn't been on here in a LONG time. Not sure what happened, but I hope he's doing okay.