BBP Tune and Octane Choice

xSHIFTxNASTYx · August 12, 2020

For those of you running BBP tunes on your truck, what tune and octane choice have some of you settled on? I'm still testing out both of them but am just curious what everyone else has decided on that have ran BBP's tunes way longer than I have. Currently running on their 91/93 tune with 93 octane fuel. Not sure I feel a huge difference in performance (not that there is much of a difference anyway, maybe 15 HP and torque extra, emphasis on maybe), but I like that most brands have better additives in their premium fuel than 87/89. My concern is deciding if the 91/93 tune and 93 octane fuel is worth the extra cost of fuel over the course of a year. Figuring that I'm paying an extra $0.70/gallon each fuel up, that's almost an extra $1,200 in fuel per year to go from 87 to 93 (roughly, if my math is correct).

Also, I'm finding random spikes of 2°-4° knock ****** on 93 octane, but they're random, like once every 5-10 minutes. It goes back down to 0° and holds steady. I'm going to assume this is false KR. I tried to do some light research but some stuff I've read has felt anecdotal. Rather common in my readings are the false KR spikes due to road noise, loud exhausts, and just basic things like a door shutting although I'm not opening and shutting my door on the freeway either. Could use some insight from more knowledgeable members on what to look for in monitoring KR with different fuel brands and ratings. I'll have to go back to the 87/89 tune with 89 octane and monitor the KR, didn't think of doing that during my first few fill ups.

tenscourts · August 12, 2020

I was told by BBP as well as the shop that did my lift never to run 87 in these trucks as the engine compression was too high. BBP also told me to expect the best fuel mileage from 89. I was running 89 but not that I'm working from home and not driving as much I'm going back to premium.

Sent from my Pixel 3 XL using Tapatalk. My build thread: http://www.gm-trucks.com/forums/index.php?/topic/192614-Tenscourts'-2016-LTZ/Z71-CCSB-4WD-Silverado

m3n00b · August 12, 2020

I only run 91 in my '16 6.2. It's only 20-30 cents more per gallon here so why even chance it? If we had 93 I would even pay more to run that.

Edited August 12, 2020 by m3n00b

Pearl2017 · August 13, 2020

I don't have a BBP tune but was scanning 17 6.2 with HPT and could see i was getting some kr just driving highway as road goes up slight elevations. The highest oct i can find here is 91 so i modded the timing map slightly where it was occurring and the truck seems to run better with 0 kr now. I don't have any hard proof but i don't think constant background knock is good for gdi injectors. Saving a few cents on gas may not be worth it.

gat0r · August 13, 2020

be careful of using cheap gas stations.

i use higher octane b/c i am boosted, so i stick w/ 93

the last time i had a loaner, i filled it the 1st time w/ 87... it didnt like that.

next time i filled w/ 89 & no issues.

xSHIFTxNASTYx · August 13, 2020

5 hours ago, gat0r said:

be careful of using cheap gas stations.

i use higher octane b/c i am boosted, so i stick w/ 93

the last time i had a loaner, i filled it the 1st time w/ 87... it didnt like that.

next time i filled w/ 89 & no issues.

Yeah, I try to stick with top tier when I can and only in high traffic areas. None of those mom and pop back country gas stations. Always makes me chuckle when an Admiral is packed with cars waiting on a pump just because their garbage gas is $0.35 cheaper than a top tier on the opposite corner (yeah yeah, nobody likes waiting on a left hand turn in the middle lane, but still).

xSHIFTxNASTYx · August 13, 2020

6 hours ago, Pearl2017 said:

I don't have a BBP tune but was scanning 17 6.2 with HPT and could see i was getting some kr just driving highway as road goes up slight elevations. The highest oct i can find here is 91 so i modded the timing map slightly where it was occurring and the truck seems to run better with 0 kr now. I don't have any hard proof but i don't think constant background knock is good for gdi injectors. Saving a few cents on gas may not be worth it.

What do you consider "constant background knock"? My situation where I'm finding a few degrees of KR every once in awhile, or when it's constantly advancing KR for long periods of time? I've read explanations that show differences in engines running 1-2° of KR every once in a while being false KR, vs an engine having 10-11° KR constantly, vs some extreme situations where wrong timings with bad gas have 30-35° of KR. I don't know enough about KR and you know how the internet is, can't always believe everything you read especially when one study says one thing and another says another. Like this one study swearing that Shell 93 is garbage gas and their v-power additives being the reason behind bad KR but in MI, at least around me, I have had best luck on gas from Shell than any other top tier brand, with Mobil supposedly being good and not that great around me - so again it feels anecdotal.

I'm just trying to understand what to look for and eliminate in KR. Guess this is why we leave it to the pros.

Grumpy Bear · August 13, 2020

9 hours ago, Pearl2017 said:

I don't have a BBP tune but was scanning 17 6.2 with HPT and could see i was getting some kr just driving highway as road goes up slight elevations. The highest oct i can find here is 91 so i modded the timing map slightly where it was occurring and the truck seems to run better with 0 kr now. I don't have any hard proof but i don't think constant background knock is good for gdi injectors. Saving a few cents on gas may not be worth it.

Motor can't measure octane but it can detect knock and so it 'test' by pushing timing to the limiting point then backs it off until it stops. Part of the programming. A motor makes best power and efficiency at what the engineers call 'incipient knock'.

The dyno mule of a new motor it is fitted with a pressure sensor, which measures and traces cylinder pressure as it happens instead of knock sensor which 'listens' remotely for what has already happened a micro second ago.

If your monitoring and don't see any KR there's money being left on the table. My 4.3 shows the same amount of KR running 87 as it does running 93. But there is more total timing with the 93. That said I've never be able to discern a measurable amount of fuel efficiency between the two. Well not enough to justify the $1 a gallon difference anyway.

Pearl2017 · August 14, 2020

Its been a while since i scanned it but i had filter set so to capture only multiple knock events. At the same time I could see timing being pulled. I applied a correction based on the scan to the timing and timing stabilized. From an engineering perspective I appreciate the ability for the ECU to control advance/KR to ride on the bleeding edge. I figured the 91 Oct was on low side for an engine tuned for 93 Oct thus more knock on the high octane timing map. I pulled up a scan you can see the timing droop down when throttle went up ~1% and some knocking. I was scanning on a trip and afterward i believe i had injector problems and had to take it in for second time. Haven't had any injector problems since clipping out the KR.

Edited August 14, 2020 by Pearl2017

Grumpy Bear · August 14, 2020

9 hours ago, Pearl2017 said:

Its been a while since i scanned it but i had filter set so to capture only multiple knock events. At the same time I could see timing being pulled. I applied a correction based on the scan to the timing and timing stabilized. From an engineering perspective I appreciate the ability for the ECU to control advance/KR to ride on the bleeding edge. I figured the 91 Oct was on low side for an engine tuned for 93 Oct thus more knock on the high octane timing map. I pulled up a scan you can see the timing droop down when throttle went up ~1% and some knocking. I was scanning on a trip and afterward i believe i had injector problems and had to take it in for second time. Haven't had any injector problems since clipping out the KR.

How slick is that? :thumbs:

flyingfool · August 14, 2020

I wonder if your picking up noise from the tranny? sloppy torque converter, pump making noise? or direct injector or AFM tripping the knock sensor? anychance you can reflash to stock ecu mapping and do a BBtune comparo

i would add some trans PIDS to your datalog, see if its picking up knock in conjunction with tcc lock up points..

also doesnt histogram feature in HP tuner do a map layout of the 3d timing curve to cross ref with your knock sensor..

i enjoy seeing more people on here using hptuners and posting up tech info..

Edited August 14, 2020 by flyingfool

MaverickZ71 · August 14, 2020

My apologies to the OP, but I've had a question floating around in my noggin for years:

We all see those goon mobiles with the thump-bump-BOOM stereo systems, where their stereo system cost more than their vehicle. Some of them shake everything for a block around, like a mobile earthquake. You know--the ones where the drivers work exclusively at the drive thrus in fast food restaurants and they make you repeat everything 10 times because they can't hear anything, and you still don't get what you ordered.

If the knock sensors are so sensitive and have such ultimate control over the engine, how do the knock sensors even allow those vehicles (and the ones around them) to run at all???

Edited August 14, 2020 by MaverickZ71

xSHIFTxNASTYx · August 14, 2020

2 hours ago, MaverickZ71 said:

My apologies to the OP, but I've had a question floating around in my noggin for years:

We all see those goon mobiles with the thump-bump-BOOM stereo systems, where their stereo system cost more than their vehicle. Some of them shake everything for a block around, like a mobile earthquake. You know--the ones where the drivers work exclusively at the drive thrus in fast food restaurants and they make you repeat everything 10 times because they can't hear anything, and you still don't get what you ordered.

If the knock sensors are so sensitive and have such ultimate control over the engine, how do the knock sensors even allow those vehicles (and the ones around them) to run at all???

That's an interesting thought. I don't have a "thump-bump-BOOM" stereo but I did upgrade my speakers. I'll crank them up and see if I can get KR to trigger.

truckguy82 · August 14, 2020

On 8/12/2020 at 6:56 AM, xSHIFTxNASTYx said:

For those of you running BBP tunes on your truck, what tune and octane choice have some of you settled on? I'm still testing out both of them but am just curious what everyone else has decided on that have ran BBP's tunes way longer than I have. Currently running on their 91/93 tune with 93 octane fuel. Not sure I feel a huge difference in performance (not that there is much of a difference anyway, maybe 15 HP and torque extra, emphasis on maybe), but I like that most brands have better additives in their premium fuel than 87/89. My concern is deciding if the 91/93 tune and 93 octane fuel is worth the extra cost of fuel over the course of a year. Figuring that I'm paying an extra $0.70/gallon each fuel up, that's almost an extra $1,200 in fuel per year to go from 87 to 93 (roughly, if my math is correct).

Also, I'm finding random spikes of 2°-4° knock ****** on 93 octane, but they're random, like once every 5-10 minutes. It goes back down to 0° and holds steady. I'm going to assume this is false KR. I tried to do some light research but some stuff I've read has felt anecdotal. Rather common in my readings are the false KR spikes due to road noise, loud exhausts, and just basic things like a door shutting although I'm not opening and shutting my door on the freeway either. Could use some insight from more knowledgeable members on what to look for in monitoring KR with different fuel brands and ratings. I'll have to go back to the 87/89 tune with 89 octane and monitor the KR, didn't think of doing that during my first few fill ups.

Justin from blackbear street tuned my truck in person.
While analyzing the stock tune data......

I quote “wow you’re not getting any knock, you have good gas in nj”

i have a 6.2 and was using 93. Considering he’s probably read more Live LT knock sensors than anyone in the world, it’s probably pretty accurate to say most people with stock 6.2’s are getting knock and pulling timing on 93!

He highly recommended I stay with 93 for the tune.

I don’t think the brand of fuel matters at all for knock. i think the quality is regional.

He said DC area has the best fuel.

Yeah filling with premium sucks. I probably get the worst mpg on the forum because of the dense suburbia I live in. If I had a 5.3 I would try to go lower octane, but with a 6.2 your stuck with 93 imo.

xSHIFTxNASTYx · August 14, 2020

12 minutes ago, truckguy82 said:

Yeah filling with premium sucks. I probably get the worst mpg on the forum because of the dense suburbia I live in. If I had a 5.3 I would try to go lower octane, but with a 6.2 your stuck with 93 imo.

I probably should have noted that I have the 5.3L motor so there is no need to run 93. I just like the idea of being tuned to run 93. Like I said before about cost to performance, since there is no NEED to run 93, I will probably stick with the 87/89 tune on good 89 gas.

Your point about it being good gas I have read on other tuner's forums as well, like Diablo and such, that they've stated they can tell on log files when someone switches gas brands due to changes in KR, specifically Shell 93 apparently being a culprit behind weird timings and KR because of their additives. It was Shell 93 that I was logging on as I frequent Shell gas in my area quite a bit more than other gas brands.

I'm almost empty so I will fill up a half tank of 89, run it out, then fill it up and see what kind of KR I get on 89. I initially had 87 in the tank when I loaded the 87/89 tune so I didn't really pay attention to my monitors.