Had my 2017 Sierra Denali 6.2l Engine Rebuilt to a 416 by Texas Speed

M1ck3y · December 19, 2021

44 minutes ago, davidvarner1064 said:

This guy did the porting

https://instagram.com/454chuy?utm_medium=copy_link

I think I'm going to send him the l86 intake I have now and have him port it for the 103mm katech I have laying around. I didn't do it before because he needed the 103mm to do the porting job. He was able to send me out a ported l86 intake right away.

Tuner also said the engine was still pulling a bit of a vacuum still and could probably use a bit more air.

He does nice work. I've seen a couple of his videos

*edit*

I wonder if removing the stands inside the manifold would benefit you. Gwatney performance did this on a 5.3 with a cam and they saw strong low end gains, but minimal top end gains.

But you have a heck of a lot more displacement, and I imagine a lot more cam then they did. Might be worth looking into?

Edited December 20, 2021 by M1ck3y

davidvarner1064 · December 21, 2021

On 12/19/2021 at 6:39 PM, M1ck3y said:

Nice, gave it a good boost. It's too bad there isn't any aftermarket truck intakes. I feel like there's a lot more power hiding in there, with your cam and displacement.

The l86 intake is great, but I'm wondering if it's to small now?

A nice cross ram intake, I bet you'd make another 80+ horsepower without affect low/mid range too much.

I totally agree that there is some more HP on the table. I feel the same way about there not being any truck intakes being made it's depressing. All they would have to do to the MSD Atomic is get rid of the downward angle of the TB opening. I thought about pie cutting it and plastic welding it straight. A minor mod and MSD would have a whole 'nother market with the truck intakes.

Edited December 21, 2021 by davidvarner1064

M1ck3y · December 21, 2021

2 hours ago, davidvarner1064 said:

I totally agree that there is some more HP on the table. I feel the same way about there not being any truck intakes being made it's depressing. All they would have to do to the MSD Atomic is get rid of the downward angle of the TB opening. I thought about pie cutting it and plastic welding it straight. A minor mod and MSD would have a whole 'nother market with the truck intakes.

Holley makes an adapter for the lt1/l86 manifolds. It allows the tb to sit level but still flow's the way it was designed to. Works on both manifolds.

It may clear the belt/pulley? At the expense of clearance from the rad.

https://www.holley.com/products/engine/accessory_drive_brackets_and_kits/gm_gen_v_lt/high-mount_accessory_drive_systems/components_and_service_parts/parts/717-15

davidvarner1064 · December 26, 2021

@M1ck3y

Still can't have my cake and eat it too. I have looked at the adapter. It's only 95mm and doesn't look like it can be ported any bigger and you also still need to relocate drive belt with Atomic. The Atomic is also ported to 103mm and necking it down to 95mm seems bad. That Katech 103mm and l86 manifold ported to the same still seems like the best option. Unless I had something professionally fabricated.

davidvarner1064 · December 30, 2021

Here is some some semi stock footage from 4 years ago on another youtube channel I forgot i had. only borla and long tubes and tune. I bought the borla with the flapper valve thinking i needed it for v4 drone. I kept DOD on. Bad move. I'm gonna get the flapper valve taken out of the mid pipe next week. It likes to resonate like a reed instrument at times even though i have it wired open. Also a couple more vids on that channel.

Jjblur2003 · January 3, 2022

On 12/21/2021 at 5:16 AM, davidvarner1064 said:

I totally agree that there is some more HP on the table. I feel the same way about there not being any truck intakes being made it's depressing. All they would have to do to the MSD Atomic is get rid of the downward angle of the TB opening. I thought about pie cutting it and plastic welding it straight. A minor mod and MSD would have a whole 'nother market with the truck intakes.

I would say its restricting you big time. Before blower I had vvt delete, stage 2 tsp 5.3 cam in 6.2, 1 7/8 headers no cats, into borla. Made 421 @6200 hp and 469 tq at 3700.

M1ck3y · January 5, 2022

On 1/2/2022 at 10:30 PM, Jjblur2003 said:

I would say its restricting you big time. Before blower I had vvt delete, stage 2 tsp 5.3 cam in 6.2, 1 7/8 headers no cats, into borla. Made 421 @6200 hp and 469 tq at 3700.

Have any numbers from before the mods?

davidvarner1064 · January 6, 2022

That seems about right. I had the TSP Stage 3 5.3l cam in my 6.2l before the rebuild. Going from a 376 to 416 is a roughly 10% increase in displacement. 421hp x .10 = 42hp. 421+42= 463hp my exact HP number that my dyno showed.

We also have the same exhaust set-up. 1 7/8 headers, no cats, and borla.

Edited January 6, 2022 by davidvarner1064