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Posted

I do have a catback that i installed when the truck had about 1000 miles on it.  Also get a huge spike in the idle if i have it in sport mode and shift from park to drive after a cold start.  Truck lunges forward hard! - but only does it once.  I also noticed they are bumping the idle about 200rpm in sport mode and they definitely  changed the scaling on the throttle.  Going past the "click" in the pedal is just more travel but doesn't trigger a kickdown like it did stock. I really don't mind that though.  If I turn the cruise on and off while sitting at a stop light my RPM's go up and down about 200.  MPG on the last couple of tanks is still to the negative.  The last tank i did some hypermiling for about half a tank and it brought it up to only -1, kinda defeats the purpose of the tune though.  I'm going to give this tune a couple thousand  more miles and then pull it out if it doesn't start to clear up. 

  • 1 month later...
Posted
Do you have a CAI or catback exhaust? I have both CAI and Borla and mileage is definitely not down unless i wanna hear the ROAR lol. Not sure why yours would be different?
 
After driving quite a bit on the tune IMO the Eco mode is not for driving in traffic. It feels just as lazy as stock and you need to push the throttle further open to take off. With ECO OFF the torque pulls right off idle and makes the truck feel lighter than it is on a lot less throttle shifting around 2k. My guess is that mode is plenty rich on fuel throwing the old emissions test @2200rpm out the window. :-)
 
On the highway in eco mode i did pick up 1+ mpg. and when i get off the fwy I turn off ECO. will be pulling a trailer cross country tomorrow in tow mode.
How did the towing go with the tune?

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2016 Silverado LTZ w/ NHT.

Posted

5430 miles total, Arizona to Tennessee to Michigan and back pulling a 33ft toy hauler. It went just fine. Trans shifted smoothly as it should and engine got a good workout with no issues at all. In Michigan replaced the tires with 285/65/20 Michelin defenders and Avg mpg was ~10.

Posted
5430 miles total, Arizona to Tennessee to Michigan and back pulling a 33ft toy hauler. It went just fine. Trans shifted smoothly as it should and engine got a good workout with no issues at all. In Michigan replaced the tires with 285/65/20 Michelin defenders and Avg mpg was ~10.
Any difference from towing without the tune? If you have.

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Posted

I don't have good MPG comparative towing data before the tune As I towed mostly locally before and felt very similar on long flat stretches. I got the tune mainly for the trans part and knowing i would be pulling up some grades on the trip. Sorry I cannot give more data points but other than MPG the rest is subjective. IMO the tune feels better than before it was applied and so that probably applied to the towing as well. I never felt that the trailer was hurting the truck or that it struggled under the load.

 

FWIW the ~10 mpg was taken from the dash and not calculated. So the larger tire size on way back is not taken into account. Generally going east with a tail wind i was doing ~14 mpg and coming back west with a strong headwind it would dip down to 8-9 mpg. Guessing actual MPG is around 11-12.

  • 3 months later...
Posted (edited)

New member here. I have a 2017 Silverado with 6.2 and 8 speed. Trifecta is claiming they can tune the 8 speed, but no one else can just yet ? Mine has about 38K miles on it now and the down shifting is ridiculous. You can hear and feel the clunking from 3rd to 2nd to 1st most every time. Sometimes I dont feel it at all. Dealer says that is normal, which I cant believe. I am willing to try anything to make this some what better. Can anyone give anymore feedback on how there tune is going on the 8 speed ? Has the downshifting issues disappeared ? I'm also concerned if i have more issues with the drive-train and need to return to the dealer, will they know I have had a tune done if i reload stock tune ?

 

 

Edited by gapple12
Posted
3 hours ago, gapple12 said:

New member here. I have a 2017 Silverado with 6.2 and 8 speed. Trifecta is claiming they can tune the 8 speed, but no one else can just yet ? Mine has about 38K miles on it now and the down shifting is ridiculous. You can hear and feel the clunking from 3rd to 2nd to 1st most every time. Sometimes I dont feel it at all. Dealer says that is normal, which I cant believe. I am willing to try anything to make this some what better. Can anyone give anymore feedback on how there tune is going on the 8 speed ? Has the downshifting issues disappeared ? I'm also concerned if i have more issues with the drive-train and need to return to the dealer, will they know I have had a tune done if i reload stock tune ?

 

 

Its possible, they have programs to search for tuning. But at the same time, tuners can tune in such a way that it doesn't operate outside of gm spec, as to not raise any red flags. Bottom line, if you like having a warranty don't tune or modify anything.  

Posted
5 hours ago, gapple12 said:

New member here. I have a 2017 Silverado with 6.2 and 8 speed. Trifecta is claiming they can tune the 8 speed, but no one else can just yet ? Mine has about 38K miles on it now and the down shifting is ridiculous. You can hear and feel the clunking from 3rd to 2nd to 1st most every time. Sometimes I dont feel it at all. Dealer says that is normal, which I cant believe. I am willing to try anything to make this some what better. Can anyone give anymore feedback on how there tune is going on the 8 speed ? Has the downshifting issues disappeared ? I'm also concerned if i have more issues with the drive-train and need to return to the dealer, will they know I have had a tune done if i reload stock tune ?

 

 

I don't recommend them. Had the advantage plus in my '17 6.2 8 speed and ended up uninstalling it. Program was buggy and the customer service is not great.  When i installed the tune the tranny shifting was firmer, and clunking disappeared at slow speeds but it eventually started coming back.  

Posted
1 hour ago, silveradosammy said:

I don't recommend them. Had the advantage plus in my '17 6.2 8 speed and ended up uninstalling it. Program was buggy and the customer service is not great.  When i installed the tune the tranny shifting was firmer, and clunking disappeared at slow speeds but it eventually started coming back.  

Appreciate the feedback. I am currently running a Edge CTS2 tuner to calibrate the oversized tires and improve mileage. It’s working good but the tranny is annoying some days. What is your plan for a tune ? Wish Black Bear could do it. 

Posted (edited)

HPTuners can unlock your TCM and you can use their tool to adjust the trans. This is the third vehicle that I have had tuned and never a warranty problem if you use your head. This 8 speed is just a fussy thing and the computers control over it appears to have a very narrow operational envelope. once something goes out of balance it acts up. We may be stuck with it But I think someone will find some tricks with it at some point. I read another thread that had some interesting advice may help with clunking if you have max tow pkg... Push and hold the trailer button for 5 secs and release you will see the message that grade braking is disabled. Something to try.

Edited by Pearl2017
Posted
On 10/4/2018 at 12:22 AM, Pearl2017 said:

HPTuners can unlock your TCM and you can use their tool to adjust the trans. This is the third vehicle that I have had tuned and never a warranty problem if you use your head. This 8 speed is just a fussy thing and the computers control over it appears to have a very narrow operational envelope. once something goes out of balance it acts up. We may be stuck with it But I think someone will find some tricks with it at some point. I read another thread that had some interesting advice may help with clunking if you have max tow pkg... Push and hold the trailer button for 5 secs and release you will see the message that grade braking is disabled. Something to try.

Thanks Pearl2017, I did disable the trans braking and it made a huge difference. All the clunking went away !!

Posted

Well thanks to all the other folks inputting their experiences here for me to relay :-) That engine braking system like stabilitrack is always in the background meddling around looking for something to do... Disable to do burnouts and now disable to keep it from engine braking up to a stop light.

  • 3 months later...
  • 1 year later...
Posted
On 1/13/2019 at 1:01 PM, silveradosammy said:

wrong post

I installed the Trifecta tune on my 17 6.2L/8 speed and have no issues works as advertised  and customer service was great. Not sure why there are some negative comments but to each his own. Would definitely recommend as GM will never fix the issue

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