March 29, 2011well i have been reading alot on this and i have been thinking about changing the octane on my blackbear tune. as of now i have the 87 octane and have had it for almost a year now and love it.but i have 3/4 ton 2500 and its a bit heavy in town driving which is 90% of what i do. i do haul some heavy loads from time to time but mostly to work and back. i get around 10 or a little less mpg in town now. i have heard that the higher octane tune could help that out a bit.but was wondering what you guys think. i also have 31 1/2 in tires on 4.10 gears. if i ever get a few extra bucks i would love to go with longtube headers and i have heard that i would be better off going to a y pipe and single 3" pipe then the stock 2 3/4 duel pipe to a di/so muffler. ant thoughts.
Forums : Performance General : octane on my blackbear tune (4843 Views)
March 29, 2011The 91-93 octane tune will help with power more on the higher end of the RPM`s and you could possibly see a hair better mileage. You`ll def. see more HP out of the higher tune.
What some people don`t understand is you can still run 87 octane while having your PCM tuned for 93. You will see a difference between the two tunes. You still have the two different fuel map tables that sense the octane and will adjust accordingly.
With that said, I couldn`t get away with towing on anything less than 91 octane. I`d get "ping" when I did with the lower octanes. Most of the time I ran 89 while the truck was tuned on 93 but I could tell the difference when I did.
March 30, 2011thanks stevens, i thought you might have some info on it.i knew you played with that on your old truck when you tuned.i think i will bump up to the higher octane. but you can run lower if ya need to and its cool? have you tune your new one?also have you heard much on the subject on the stock duel to muffler single out, at the 2 3/4" pipe. i have been reading and the y pipe to a single 3" sounds like a good gain. but exhaust are like opinions. i know i what to get longtubes for sure.or tri Ys. any thoughts? thanks alot
March 30, 2011I`m getting the new truck tuned end of April by Blackbear. Can`t wait to see the difference. Can`t help you on the exhaust question,... obviously alot of variables but if I were to do headers, I`d pick long tube for sure. The LS motors need some back pressure to make low end torque, so more often than people will admit, putting anything over 3" single or 2-1/2" dual out the rear causes loss of low end torque.
I had corsa dual exit on my Vmax and was very pleased with the results, (mostly sound). Not sure what to do if anything on the new truck. It already sounds great, but I miss the dual exit look. And.. it could be a hair louder.
March 30, 2011thanks man, i think your right about the back pressure topic. from what i read the whole stock duel to the muffler was the set up for 8.2L or what ever size it was.and 6.0l was the other option. thanks for the imput. i for sure am going up on the octane tune and may upgrad to the scan cable as well. he did really good on the tune with out any data. but at 35-45mph i have a large drop in rpms in that shift that seems to want to be a little tweeked. let us know on yours when you do it. thanks alot.you are one of the biggest reasons this site keeps rocking.keep it up.
August 2, 2011update: finally getting ready to up grade my tune. i decided to go from the traditional tune to the scan cable. i would do the auto cal but as of now i dont need it. but for the tune im going up to the 93 octane for sure. i will let ya know how i like the new tune once i have had time to get it all adjusted.
August 20, 2011small update: did a few scan logs and sent them in. going up in octane to 93. and see what else come of it. keeping my fingers crossed.
September 2, 2011update: the pcm came in the mail last night! havent put it in yet. i have a little gas to run out before i can. should be tomorrow. but through conversations with justin it looks like the quality of the 87 octane here in lexington sucks.no wonder my mpg dropped off the face of the planet when i moved here.....so he made some changes to the tune and up the octane to 93. i will let ya know.
September 3, 2011Hopefully it helps you becuase that MPG seems extremely low to me, I drive a 350 lifted with 33"tires and 140k miles and low end get 11 and I usually average 12-14 with the occasional 15MPG tank..good luck
September 3, 2011crossing my fingers. hoping to put it in later today.
September 4, 2011got it in the a.m.! took it for a short spin and WOW! powerful.even more that before. i will post up real numbers later.
September 9, 2011FINAL UPDATE: so the results are in! going from the traditional tune/87 octane to the scan tune and jumping up to the 91+ octane was well worth it. in town i got a 2 1/2 mpg increase! so it turns out that the 87 octane gas here sucks! and justin dialed in my maf sensor and up to the higher octane...now it runs smoother and idles better. its a beast. if you are looking into a custom tune spend the extra 100 bucks and go for it. i had the traditional tune for a little over a year and loved it but always wondered if it the higher oct. wound have been a better move, plus the upgrade in tune......thanks justin at black bear performance.