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Posted

For those of you with 2014+, you should not be running anything less than 89 octane...

Can you please elaborate on why this is?

Posted

Can you please elaborate on why this is?

I believe because of the compression of these engines, or at least the 5.3. Even BB advises to run minimum of 89 octane.

Posted

Can you please elaborate on why this is?

I run tier 1 87 in mine as is recommended by GM in the owners manual. 6.2's are 91 minimum. 87 is all the company will pay for so that is what i run since i am 700 miles a week. I was looking at data and did not notice any knock retard being used during any acceleration. I assume this is because BBP never adjusted my timing off of the GM setting. Justin recommended 89 as it may be more fuel efficient. The compression is allowed to be this high as fuel doesn't enter until just before the plug fires. on my 64, it was built at 10.5:1 running on 100 octane gas. i have to pull timing and run 91 shell or 93 other to prevent detonation. With the fuel entering just as the spark plug fires, aluminum heads and block, 11:1 is achievable on 87

Posted

At 11:1 compression ratio (DI or otherwise) the engine *cannot* efficiently run 87 octane under any circumstances. As a result, knock occurs (heard or unheard) and the ECM retards ignition timing both immediately and long term. The result is reduced fuel efficiency (sometimes as high as 3-4mpg) and considerably less power output than would be seen on 89 octane. You won't notice this power loss under light throttle though due to the ECM's method of controlling throttle angle... essentially, the throttle will be opened more for the same power output target on 87 as 89 so that it feels exactly the same to the driver.

 

In terms of ignition timing, where 18-19 degrees of advance might be the target by GM under the factory tuning, on 87 octane, that timing drops to under 10 degrees of advance to prevent knock from occurring (in response to knock that has already occurred). Anybody that has dealt with ignition timing should see this as a very poor situation. The knock retard occurs early and quickly and then the lasting effects (octane scaler blending the high and low octane tables) will stay in effect for dozens of miles before decaying out.

 

GM doesn't recommend any higher than 87 because they know that a) they will be vilified for doing so by consumer reports, motor trend, car and driver, etc and b) they know that people won't listen.

  • Like 1
Posted

Exactly, heck even customers with the 6.2l trucks wont run 91+ because they don't want to spend the extra money on the gas. Case in point, girl I work with has a GM truck with the 6.2l, she didn't even know the truck had it. I mentioned did the dealer tell her she had to run 91, she said nope. I pointed out the gas cover states 91 only on the 6.2l trucks, she still puts 87 in it because she doesn't want to spend the money.

 

I have never ran less than 91 in my truck, I even made sure to tell my dealer when they filled it up to not put anything less than 91 in it, when they tried to rebut it by saying it wont hurt I told them it is stated in the manual and on the gas door. They finally listened and put 91 in for me.

  • Like 3
Posted

 

I have never ran less than 91 in my truck

 

Same here from day one. I tried 93 for a while, but didn't notice any change in mpg. Not sure if it (93) will make any other difference, but 91 seems just fine.

Posted

Although I don't disagree with your logic, in fact I agree with it, when the boss is willing to pay up to $200 a week for gas I will have go that route. That's a mortgage payment every month. So I guess I will have to take the lower power output. That is really the only reason I run 87 vs 89. If I can prove 89 will save him money he may go for it

Posted (edited)

Well now that I am thoroughly confused after reading 53 pages of this.... Im going to need a beer.

 

I bought a 2016 Silverado with the 5.3 as a birthday gift to myself 2 weeks ago and instantly began looking for ways to make it better. I immediately noticed the terrible throttle response and soft shitting and knew it needed to be changed. The only programmers I've ever used, or had any experience with were plug and play types. My buddy has a hypertech for his 2011 Silverado so I've been able to mess with it a bit. Unfortunately the cost, either custom or handheld, is a little more than I can afford right now so it's going to have to wait. But glad to see that I'm not the only one worried about the warranty issue. This is my first new vehicle so I'm hesitant to tune. But what the hell right, why not?

 

So if I understand this correctly, and I'm probably wrong, Diablo is sort of a semi custom tune with a hand held? The Diablo will allow the end user a little more access to tweak/tune a few features than a programmer like bully dog or edge would, which have preset tunes, correct? the end user can seamlessly switch back and forth between stock and tuned when taking to the dealership?

 

And black bear is a custom tune which requires the end user to drive a designated amount of time allowing for the data logging. The data is then sent back to black bear with the list of changes we would like to see. And then flashed back onto the truck.

 

But of course since I've only had the truck a few days all the terminology and abbreviations are confusing the heck out of me. AFM, active fuel management? Is this v4 vs v8 mode? And it sounds like it's best to have this deactivated. Torque management? If I read correctly, there is a TM for the transmission and the engine? What the purpose of this? And clearly the shift points and throttle need a tremendous amount of correction so the truck has better drive ability.

 

I have no problem wrenching on or building cars. I've built or rebuilt several cars trucks tractors and motorcycles already, I come from a farming background so it comes naturally. But when it comes to all this ECM tuning it is way over my head. I prefer carburetors.

 

**Edit: I realized I was an idiot and forgot about the other pinned thread literally titiled Active Fuel Management. So that answered one question. Lol

Edited by Spurly
  • Like 1
Posted

Well now that I am thoroughly confused after reading 53 pages of this.... Im going to need a beer.

 

I bought a 2016 Silverado with the 5.3 as a birthday gift to myself 2 weeks ago and instantly began looking for ways to make it better. I immediately noticed the terrible throttle response and soft shitting and knew it needed to be changed. The only programmers I've ever used, or had any experience with were plug and play types. My buddy has a hypertech for his 2011 Silverado so I've been able to mess with it a bit. Unfortunately the cost, either custom or handheld, is a little more than I can afford right now so it's going to have to wait. But glad to see that I'm not the only one worried about the warranty issue. This is my first new vehicle so I'm hesitant to tune. But what the hell right, why not?

 

So if I understand this correctly, and I'm probably wrong, Diablo is sort of a semi custom tune with a hand held? The Diablo will allow the end user a little more access to tweak/tune a few features than a programmer like bully dog or edge would, which have preset tunes, correct? the end user can seamlessly switch back and forth between stock and tuned when taking to the dealership?

 

And black bear is a custom tune which requires the end user to drive a designated amount of time allowing for the data logging. The data is then sent back to black bear with the list of changes we would like to see. And then flashed back onto the truck.

 

But of course since I've only had the truck a few days all the terminology and abbreviations are confusing the heck out of me. AFM, active fuel management? Is this v4 vs v8 mode? And it sounds like it's best to have this deactivated. Torque management? If I read correctly, there is a TM for the transmission and the engine? What the purpose of this? And clearly the shift points and throttle need a tremendous amount of correction so the truck has better drive ability.

 

I have no problem wrenching on or building cars. I've built or rebuilt several cars trucks tractors and motorcycles already, I come from a farming background so it comes naturally. But when it comes to all this ECM tuning it is way over my head. I prefer carburetors.

 

**Edit: I realized I was an idiot and forgot about the other pinned thread literally titiled Active Fuel Management. So that answered one question. Lol

The diablosport tunes are not custom tunes. They are preset tunes similar to Edge etc, Im working with Diablew on building a custom tune now. Black Bear did my 2012, did a great job.

TM is to prolong the life of the transmission, it just cuts back power during shifting to avoid excess wear and stress basically. Ill post on my experience with Diablew tomorrow or the next day. The first tune i got from him this morning, wasnt good at all..

Posted

Quick question forgive me if it was answered previously, but why won't 2015 6.2 8 speed canned tunes work on a 2016 6.2 8 speed, what exactly changes that makes them not compatible? Thanks

 

Sent from my E6853 using Tapatalk

Posted

So I installed my headers this weekend and now my check engine light is on which I knew would happen but when I'm stopped my idle is kind of rough is this something BBP can fix with a tune? I'm going to get the AutoCal just waiting for funds lol.

Posted

The diablosport tunes are not custom tunes. They are preset tunes similar to Edge etc, Im working with Diablew on building a custom tune now. Black Bear did my 2012, did a great job.

TM is to prolong the life of the transmission, it just cuts back power during shifting to avoid excess wear and stress basically. Ill post on my experience with Diablew tomorrow or the next day. The first tune i got from him this morning, wasnt good at all..

Ok, I knew I was probably wrong! Thanks for the clarification!

Posted

Found an intune in my area used for the right price worth picking one up for my 2015 5.3 sierra?? Canned tune improvement over stock just looking for maybe some better mpg and shifting never used a hand tuner before simple to use?

 

Sent from my SM-G900W8 using Tapatalk

Posted

So I installed my headers this weekend and now my check engine light is on which I knew would happen but when I'm stopped my idle is kind of rough is this something BBP can fix with a tune? I'm going to get the AutoCal just waiting for funds lol.

Yep! You just need to be tuned for the headers.

 

Sent from my fone.

Posted

Several of us who have data logged these motors agree that 89 (personally 91+) octane should be used. The truck pulls a pretty good amount of timing on 87 octane.....

 

On the switch to V4 there's a lot of KR (under low load not a huge issue).

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