u/chim_richels

Updated my 26 AT4X with the 663.30 software this weekend. A few posters had mentioned an improved throttle response post update.

I noted this as well- on the first drive post update, the truck felt significantly more aggressive. Immediate shove on light throttle. Fairly impressed.

However, while there's still a slight overall improvement, that initial sharp (fun) edge is now mostly gone. Drove 40 miles to work this morning, and while it's better than it was before, it's still very tame. Not necessarily a problem, but it got me thinking.

Years ago I got a Cobb tuner for my Ecoboost Mustang (6spd) that I briefly owned before trading it in on a GT. Anyway, I flashed the car with the tune Cobb provided, and took it out for a test drive. It absolutely *ripped*. Like hilariously fun to drive. Just crazy aggressive power everywhere. I remember thinking "why bother with the GT?" Parked it, grinning ear to ear. Next drive, completely different car. Mellow, soft, slightly better than stock but nowhere near as thrilling to drive as the day before.

Called a well respected tuner for these cars and he basically said the tune file effectively booted torque management temporarily. I didn't even know what that was at the time. He gave me some additional tune files to data log against, he reviewed them and said everything looked good. I just could never get that raw aggressive feel back.

After I updated my truck, that's the initial feeling I got from it. An instant, willing, sharp response.

Now that's it's back to baseline, even if slightly improved, I'm wondering if the torque management is just super heavy handed on these trucks. After getting a brief glimpse of how the 2.7 can feel, it's difficult to ignore. Livernois talks a lot about how their tune isn't just about peak gains, it's about refining driveability as well.

TL/DR: I suspect the 2.7 Turbomax engine's personality is being held hostage by overly aggressive torque management and trans tuning focused on longevity and fuel economy. (Might be a common sentiment.)

New thread so anyone else that might encounter a similar issue can find it. Follow up to this post:

https://www.reddit.com/r/GMCcanyon/comments/1vd533i/aaaaand_its_dead_688_miles_no_start/

The starter was dead, would not engage "fry wheel" in the tech's notes. Replaced. Truck back home.

Insane.

Just getting to know my 26 AT4X, couple of things I thought were problems that were not.

First- odd rattling sound going down the road over bumps. Vaguely coming from passenger rear seat area. Thought maybe it was some loose items from the car I traded in that I chucked under the rear seat.

Nope. The passenger rear seat belt was turned around and hitting the pillar. GMC puts a loop of belt on the backside to cushion it when its facing the right way to prevent this noise, but my son was back there and must have turned it around when he exited. Noise gone now. Duh.

Second- getting in after work, fumbled phone in my hand, caught it, but in the process I accidentally swiped down and had to close some random menus that popped up. Started the truck, android auto connected, but I only had faint audio coming from one speaker. Fiddled around with unpairing and repairing the phone to the truck, soft reset the system, same issue. Went back into my phone's quick menu settings and saw a couple of random ones I never have enabled were turned on, one of which was not permitting the audio setting over the Bluetooth connection to the truck. Switched those off, and back to sweet bumping Bose goodness. Also, duh.

Couple weeks in and I absolutely love this thing. It gets so many compliments. I've never owned any other vehicle that people ask me about this frequently. Dudes *love* trucks. People at work that I never interact with have approached me to ask if it's mine. A couple of guys have told me that they went to their local dealerships to look at them- wild.

Cool story, I guess? 😄

Was considering a K&N intake for my 2026, but the reviews are mixed. They claim some optimistic gains- wondering if anyone has done one, and what your thoughts are.

So my 2026 Tuono 660 Factory has had an annoyingly loud rear brake from literally day one. Lots of people say "it'll go away eventually" and that may be true, but I just couldn't deal with it, and taking it back to the dealer is a huge pita.

To be clear, this did not sound like a pad squeak. This was a clown horn honk at light pressure- like when I'd feather the rear in slow moving traffic just barely moving. So right as there are cars all around me, hooooonk. Awful.

So, pulled the Aprilia TSB, which lists two "fixes" depending on the type of noise. High pitch squeal, check for presence of shims on the pads. Yep, they're installed. And that's pretty much it for that one. The second is the loosen the axle and jam a rag in the chain, load the axle by rolling back the tire and pushing any slop out of the caliper mounting point, then torque the axle nut while holding all of that in position

Tried that axle loosen/tighten method with my wife's help, but just had her snug the axle as she wasn't quite strong enough to torque it. So I let the pressure off the tire and the caliper *before* the axle nut was fully torqued. That may have been a mistake- try fully torquing the nut while maintaining load on the axle and caliper first- maybe that alone will work for you. Bike has to be on rear stand, btw.

So, here's how I fixed it:

Supplies:

$35 for a new set of SBS sintered "street" rear brake pads. Should I have to buy new pads? No. But I was determined to eliminate potential issues.

One bottle of CBC disc brake pad quiet. It's basically red liquid silicone rubber.

One little tube of brake parts grease

Procedure:

Separate ABS sensor cable from rear brake line

Remove caliper- 2 10mm bolts

Remove circlip from pin on the back of the caliper

Remount caliper on disc- punch pin out of caliper through wheel on other side of bike (easier than trying to hold caliper and driving pin out.

Remove the top spring and pads

Remove the metal shims from the pads- note arrows and mark orientation

Take a small amount of the CBC disc brake quiet and spread a thin layer across the back of the new pads. Thin enough that you can still make out the text on the back of the pads. Let dry for about an hour so it fully sets up.

Reinstall the shims in the correct orientation.

Spread another thin layer of disc brake quiet on the shims. Let that dry completely.

Using the brake parts grease, lightly grease the face of the mounting bracket, the back of the caliper bolt holes, the spring, and the pin. Use a toothpick to get a little bit of grease inside the cutouts in the pad tabs. Obviously don't get grease on the pad surface. Hit the rotor with brake clean and wipe down.

Put the brakes back together and reinstall. If you need to open the pads up a little to fit them over the rotor, loosen your rear brake reservoir cap and use a wide flat blade screwdriver to gently nudge open the pads. It takes very little force to push the caliper piston back, and have a rag ready to catch brake fluid from the reservoir.

Tighten it all back up

Then I did the axle loosen/rag in the chain procedure again, this time with my son holding the tire and caliper while I fully torqued the axle.

No noise from the rear brake at all. Ran them in per spec and not a peep. So nice not hearing the honk.

Was it doing the axle procedure properly the second time? Was it the pads? Was it the disc brake quiet application? Greasing all metal to metal contact points? Not sure, but it's finally silent like it should be.

Apologies for the wall of text. Hope it can help someone else out. Good luck.