Tuning 2012 Yukon 6.2, Need Redline Advice

[cp-the-nerd]

Wow, the stock tune on these things is super conservative. The 1st gear WOT shift is 5725 rpm, 2nd and 3rd gears are both 5425. Is there any reason I can't go 5900 for all 3 gears? Stock engine extreme cutoff is set to 6100 rpm, overspeed lamp comes on at 6000.

Anyone have experience tuning GM 6.2L trucks? I'm open to suggestions. This Yukon is a Denali with an LS3 throttle body and bigass airaid dry cone intake, which is why I want to rev it out to 5900 rpm.

I've already reduced the torque management and smoothed out the shift pattern to something more responsive. Stock tune attached.

2012_GMC_Yukon_6.2_Gavin_Stock.hpt

[5FDP]

Should be fine going to 5800-5900.

You can improve the tune a lot more past this too. Aim for a leaner AFR around 12.0-12.3, lower the delays settings, play with VVT down low and the transmission could be tuned more to offer crisper/cleaner shifts with just a few changes to shift time and pressure presets.

[cp-the-nerd]

I appreciate the quick response, I'll haven't done much with the actual shifts yet because it's a vehicle my buddy shares with his wife. The shift table alone has been a massive improvement over stock. Just looking at the stock tables of pretty much any GM 6-speed 2007-12, what were they thinking?? Terrible.

[5FDP]

I haven't had a problem with the shift speeds they set from the factory, I think they shift fine at the mph's they already have. My truck has 3.42's so it's not too bad.

I just dislike how long the shifts are, how soft and how soon they apply the torque converter around town. I always disable the torque converter lockup until 5th gear instead of 3rd and 4th like factory, makes it drive nicer in my eyes.

[IARLLC]

As usual I would agree with 5FDP's good advice.

One thing I would expand on is the VVT table advice. Since the Denali already starts to retard cam timing just off idle, the big (night and day) difference you can get will be copying your Med baro VVT table to the High baro VVT tables (Airflow>Variable Camshaft>Intake Camshaft---). You might reduce the VVT retard bump (I call it EGR over-retard) on the Med baro table as well. I don't completely get rid of it like the Low baro table since there is a minor benefit to it as long as it does not interfere with light/medium throttle power.

These adjustments to the VVT tables raise cylinder pressure in those regions considerably. As the 6.2s have a bit of compression I log the specific areas where the EGR bump was adjusted down (before and after) and reduce timing on the Spark>Advance>VCT table in the areas that experience increases KR. Please note that I don't try to get rid of all KR on GEN4s as they become weak and less efficient.... Instead, by logging before and after I note for instance that it used to get 1 or 2 degrees of KR in a region and after the VVT adjustments the same areas get 3 or 4 degrees of KR.....so I take those 2 degrees from that region of the VCT ignition table as the increased KR is specifically related to the change in VVT.

I have found with these changes that I don't mind the low RPM part throttle shifting GM puts into them. As 5FDP confirmed, no problem raising the full throttle shift to 5900.

[Area47]

you can run it out to 6200 if the cam tables are good and still make power.

[cp-the-nerd]

I did see that the stock 2010-15 Camaro SS automatic tune had a 6300 rpm extreme fuel cutoff, which supports your statement, but this tune wont be quite that aggressive. My buddy just wanted something that would compliment his simple intake mods. The truck has taken very well to the changes, and each revision I try to take performance a bit further than the last.

I'm going to post some info about the stock transmission tables when I make my next changes, because there are things I see GM doing over and over that bug the crap out of me. Like locking out 1st gear downshifts if you're going faster than 20 mph. Might end up a bit of a rant, but I'll have tables and advice from my experience tuning GM's fwd and rwd 6-speeds.

[Area47]

pre cam, i ran my L9H to 6400 and was still holding power there. the hp flattened after 5900, shifted it at 6200. after the cam was 7k on max rpm.