2014 Siera/Silverado 6.2 owners - need help

[typhoon186]

2014 Sierra 6.2 with Long Tube header and Diablosport In-Tune Custom tune. The stock rev limit is supposed to be 6,000 rpm. My custom tune has it moved up to 6,400 rpm. But for some reason, mine will not pull past 5900 rpm. It pulls real strong up to that point, then just completely stops pulling like you killed the engine. After the shift, it starts pulling again. I even tried it in manual shift mode and same thing. Can anyone else with IN-Tune raise their rev limit and pull past 6,000 rpm or is it just me? Lew and Mike have looked at my tune and said all looks good with rev limit set at 6,400 rpm. I know other trucks with HP Tuners say they can pull hard all the way to 6,400 rpm. So I'm trying to figure out why I can't. Need some help.l

[typhoon186]

I think what I am finding is adjusting the rev limit on the In-Tune really does not change the truck's actual rev limit. Stock rev limit in 1st and 2nd is 6,000 rpm. The maximum the In-tune will adjust is +/- 400 rpm. I set it at 6,400 rpm and the truck pulls hard to just over 5900 then shuts down like it hit the rev limit. I then set the rev limit to 5600 rpm and the truck will fly past the 5600 and fall on it's face again just over 5900 rpm.

Can someone else with a 2014 6.2 truck and In -Tune try adjusting you ecm rev limit up and down to see if it has any affect on yours and report back?

Thanks very much,

Jim

[AZNikko]

Sorry I don't have any resolution but I wanted to agree that your not losing your marbles on this one. I updated mine, even got custom tune. Will not rev above 5900, I would expect it to be a fail safe measure?

Nikko
2014 Silverado 5.3

[typhoon186]

Thanks, glad it's not just mine. Diablosport is working on it. HP Tuners is able to raise the rev limit with no issues so There must be something with In-Tune that needs to be corrected.

[Zach]

Sorry I don't have any resolution but I wanted to agree that your not losing your marbles on this one. I updated mine, even got custom tune. Will not rev above 5900, I would expect it to be a fail safe measure?

Nikko
2014 Silverado 5.3

Nikko,

Please post up or email me your backup and last tune written and I will address the issue.

[typhoon186]

Nikko, that's on a 2014 5.3?

[typhoon186]

UPDATE!

Zack Hill, Diablosport Calibrations, found and corrected the glitch. If you have a 2014 GM truck be sure to get this done to your tune! Especially with the 6.2. I have my shift points set at 6,200 rpm 1st - 2nd and 6,100 rpm 2nd - 3rd. Then drop 100 rpm for each gear after that. After the shift from 1 to 2, it is now only dropping back to about 4,050 rpm (right in the sweet spot) vs. about 3,750 shifting at the stock 5800 rpm. Then it pulls harder after the shift because it's higher up on the steep part of the hp curve and in the middle peak area of the torque curve. If you have stock exhaust and intake, you may want to shift a little earlier like 6,000. I increased shift firmness to +8% at part and WOT and that's feels good to me.

Here' what I had to say about it afterwards:


SWEET!
PERFECT!
AWESOME!

That is what I’ve been waiting for. Clean, strong pull all the way to the shift, then a quick positive shift and immediately back to full power pulling again. Almost a seamless transition from gear to gear with no loss of power. There is no doubt this will improve my 0-60 mph, 0-100 mph, 1/8 mile and ¼ mile times. I’ll log that info this week end and post it. And makes it so much more fun to drive.



Thanks, Zack.

[mikel]

good deal