Air Intake (and a couple other mods)

David Opalinsky · May 25, 2020

Hi All,

First time post here. I have a 2015 Sierra Denali that I recently made some upgrades on. I upgraded my headlights to HIDs, I installed a cat-back exhaust system, and I changed out my air intake. I am seeking some feedback on my air intake. However, before I get to the air intake, I thought I would share what the other mods were for interest sake. The HID headlight install was quite straight-forward thanks to YouTube and it made a huge difference. I noticed quite a few questions and concerns about headlights but I had no issues with mine so I thought I would share the link for where I purchased them; https://absolutehid.ca/gmc-sierra-hid-kit.html. As for the exhaust, I went with a Borla S-Type and it sounds pretty wicked. Much more deep and throaty, which matches the look of these trucks. The exhaust install was also straight-forward thanks to YouTube. The hardest part was getting the old exhaust out without a lift, which meant I had to cut the old one to get it out. A bit painful when you aren't a mechanic with all the right tools but it was done in about 3.5 hours.

Anyway, on to the air intake. I installed a K&N Blackhawk system. Again, the install is very simple and overall the results were very good. I installed this prior to adding the new exhaust and I was surprised what a difference it made to the sound. It actually results in a noticeable growl as you accelerate, which is really cool. I am sure that it will help with towing, power, and mileage a little bit (especially combined with the exhaust). However, I am noticing an odd anomaly with it. If I step on the gas really quick/hard, I hear a split-second gulp and then the engine roar. It's almost like a slight stutter right before it kicks in. I assume that it is maybe gulping in a lot more air and the engine is now dealing with that but has anyone else experienced something similar? Perhaps the sensors need time to adjust? I have had no sensor/error messages and the truck runs and idles beautifully otherwise. Has anyone had to get a tune after get a new air intake? I should note that this split-second stutter happened prior to putting the exhaust in so it is definitely related to the air intake.

Thanks!

SeekAndDestroy · May 26, 2020

I have pretty much the same setup, cat back exhaust with a CAI. The truck will take some time to tune itself, about 500 km and 10-20 hot/cold cycles. I take my CAI off for winter, and that's usually how long it takes. The bog, or hesitation, you are getting might get a bit better after the truck learns the new air to fuel ratio it is getting. My truck has the 6.2 and 8-speed and the bog was always there. I bought the Soler Performance Throttle body and, wow, what a difference. It got rid of that lag/hesitation and the mushy pedal feel. A tune will let you get the most out of the CAI and exhaust. I will be getting a tune after warranty is up. Hope that helps.

David Opalinsky · May 27, 2020

Thanks @SeekAndDestroy. I appreciate the feedback. Other than the bog you note, I love the 6.2. Since my warranty just ended, it’s probably a perfect time for a tune. I will also check out the throttle body you referenced. This will probably turn into an addiction with a turbo charger in the future...