Input or advice from others on cam swap for 6.2L 2011 Yukon Denali

[hagar]

I hear you, but that’s exactly what I did, and it’s working great for me. I’m not trying to debate anyone here. I’m just saying that I have never seen any evidence of what the actual power gains are for VVT at lower RPMs. I hear lots of hand waving and wows, but there seems to be two sides to this issue, and no clear resolution with data.

You mis understood me, unless you kept your vvt system and installed a non vvt cam. I have done lots of vvt deletes, it used to be all I did automatically for years. I meant there is a reason people don't put a non vvt designed cam into a vehicle and still retain the vvt system. A vvt cam is designed differently than a non vvt cam. My point was that tooley advancing and retarding a non vvt cam that wasn't designed for the system, isn't a very good control for an experiment on the benefits of a vvt system.
It is just the internet, I might not even have a car for all you know, just telling you my above average experience from 20 years of building and tuning efi vehicles.

 

[Geotrash]

You mis understood me, unless you kept your vvt system and installed a non vvt cam. I have done lots of vvt deletes, it used to be all I did automatically for years. I meant there is a reason people don't put a non vvt designed cam into a vehicle and still retain the vvt system. A vvt cam is designed differently than a non vvt cam. My point was that tooley advancing and retarding a non vvt cam that wasn't designed for the system, isn't a very good control for an experiment on the benefits of a vvt system.
It is just the internet, I might not even have a car for all you know, just telling you my above average experience from 20 years of building and tuning efi vehicles.

Got it. Thanks for clarifying. That makes sense. I still wish there was a good set of data points for an otherwise similar cam between VVT and non-VVT to be able to isolate just how much gain it really offers down low.

 

[hagar]

This thread is a great resource that I wish I'd had when I did mine a couple of years ago. I'm still happy with the setup I landed on though. Cam Motion Stage 2 truck cam (3-bolt), Chevrolet Performance LS7 lifters with BTR beehive springs and moly pushrods. Just finished a 2500 mile camping trip through the northeast pulling our 7500 lb camper, and never ran short on power anywhere. On a few long grades when I had to downshift to 3rd, I had to keep my foot out of it or it'd keep accelerating.

Side note: I have never been able to find a chart or performance data for VVT vs non-VVT at lower RPMs where it's supposed to be most effective, so I'm still skeptical of its benefits outside of fuel mileage. I also have a 2007 XL Denali that still has the stock cam and VVT and the 2012 with the 3-bolt cam will outrun it off the line pulling the same camper, all the way through the rev range. On the same highway entrance ramp near my house, I'm 10 mph faster merging onto the highway with the 2012 than I am with the 2007 when towing. The only significant difference is the cam. And both are Black Bear tuned for premium fuel.

What cam is in the 2012?

 

[hagar]

Got it. Thanks for clarifying. That makes sense. I still wish there was a good set of data points for an otherwise similar cam between VVT and non-VVT to be able to isolate just how much gain it really offers down low.

Here is a back to back test with just a stock cam. The thing about the aftermarket vvt cam is it still pulls super hard down low, much harder than stock does. I don't doubt your 2012 pulls harder than the 2007 if the cam is aftermarket. More power pulls harder for sure. That's not to say it wouldn't be even better if it was a vvt aftermarket. The key is you are super happy with the cam, I am sure it works great!

GM Gen IV VVT Dyno Data

Since its release, the benefits of GM Gen IV Variable Valve Timing (VVT) technology have been unknown to the performance aftermarket. Mast Motorsports recently conducted testing during the development of our L92 turnkey crate engine package to determine the performance gains of the GM Gen IV cam...

www.pro-touring.com

 

[Geotrash]

Here is a back to back test with just a stock cam. The thing about the aftermarket vvt cam is it still pulls super hard down low, much harder than stock does. I don't doubt your 2012 pulls harder than the 2007 if the cam is aftermarket. More power pulls harder for sure. That's not to say it wouldn't be even better if it was a vvt aftermarket. The key is you are super happy with the cam, I am sure it works great!

GM Gen IV VVT Dyno Data

Since its release, the benefits of GM Gen IV Variable Valve Timing (VVT) technology have been unknown to the performance aftermarket. Mast Motorsports recently conducted testing during the development of our L92 turnkey crate engine package to determine the performance gains of the GM Gen IV cam...

www.pro-touring.com

Wonderful! That’s exactly what I’ve been looking for, thank you! And if I’m understanding you correctly, an aftermarket cam ground specifically to take maximum advantage of VVT can have even more gains? That’s terrific.

It was also my understanding that the phasing was pretty binary - either fully advanced or fully retarded, but it seems that’s not the case?

 

[Geotrash]

What cam is in the 2012?

It’s a Cam Motion Stage 2 Truck Cam specifically for the 6.2:

 

[hagar]

Wonderful! That’s exactly what I’ve been looking for, thank you! And if I’m understanding you correctly, an aftermarket cam ground specifically to take maximum advantage of VVT can have even more gains? That’s terrific.

It was also my understanding that the phasing was pretty binary - either fully advanced or fully retarded, but it seems that’s not the case?

The cam angles are in a large table that references both engine rpm and load, there is full control from idle to red line, there are also separate timing tables that modify spak from the normal base timing based off the various cam angles. That is why you see the peak power finish the exact same, yet the difference below is very uniform in its gains up until that point. So that pull starting at 2 thousand rpm would be retarded 18 degrees, then at 2200 it might be -17 degrees, then at 2400 it might be -16, and so on, until it reaches the point where the cam being locked static, is at, and they become the same power.
And yes, an aftermarket version follows the same pattern, just in a higher amount. The peak power from a vvt 2 l92 tsp cam will be around 80 hp more than stock, but it's average power follows suit along the path to that peak power.

 

[Geotrash]

The cam angles are in a large table that references both engine rpm and load, there is full control from idle to red line, there are also separate timing tables that modify spak from the normal base timing based off the various cam angles. That is why you see the peak power finish the exact same, yet the difference below is very uniform in its gains up until that point. So that pull starting at 2 thousand rpm would be retarded 18 degrees, then at 2200 it might be -17 degrees, then at 2400 it might be -16, and so on, until it reaches the point where the cam being locked static, is at, and they become the same power.
And yes, an aftermarket version follows the same pattern, just in a higher amount. The peak power from a vvt 2 l92 tsp cam will be around 80 hp more than stock, but it's average power follows suit along the path to that peak power.

Fabulous! The heads on the L92/L94 flow so well that it's silly not to take full advantage of it.

Well, I suppose there is nothing keeping me from going back to VVT someday. I don't welcome the prospect of tearing back into it, so I'll probably leave it as-is for some time. But it's great for others to have this info to make more informed decisions with as they go, so thank you for taking the time to share your expertise and knowledge with us! I'll update my cam swap thread with this info also as I know a lot of people have referred to it in making their decisions.

 

[donjetman]

I like to see the guys on MotorTreads "Engine Masters" tackle this:
https://www.motortrend.com/plus/show/engine-masters/645/

 

[JPS0284]

BTW, my number one trade of customers is HVAC guys, there must be some sort of correlation there if a guy thought hard enough about it.

Lol must be. So I’m getting ready to make the order but I’m a little confused which would be the better choice since I’m not going to be changing out the torque converter….yet.. What would you go with? (I plan on getting a set of the Johnson lifters as well)
1.)TSP L92 Stage 1 216/228 .600”/.600” 113LSA
2.)TSP L92 Stage 2 220/232 .600”/.600” 113LSA
3.)TSP L99/L92 Stage 2 212/218 .600”/.600” 112LSA

 

[hagar]

Option 3 is a 5.3 liter vvt cam. Either go option one or 2. If you are going to be tuning it yourself with no prior knowledge, it will be easier with the smaller cam, but that doesn't mean it will suddenly be easy, just a little less work to get it to idle properly. If you want to error on the side of better towing, go with the stage 1. If you want capable towing with a little more upper end power, go the stage 2. With the 6 speeds it isn't a problem finding the correct range to be in If it is tuned correctly to not lug shift like they do stock. You should be shifting a 6 speed at 2 grand at light throttle for each gear for best economy, not lugging it down as fast as they can get it into 6th, like factory. You will never have a problem towing with the stage 2 if it's tuned properly. Just leave the converter unlocked until 5th, and have it shift at 2 grand through all gears, and it will pull like a champ. And of course watch your tranny Temps, and do an aux cooler installed before the factory cooler if it needs one. Being in Michigan you will want to run the tranny fluid through the stock rad location to warm it up in the winters.

 

[JPS0284]

This thread is a great resource that I wish I'd had when I did mine a couple of years ago. I'm still happy with the setup I landed on though. Cam Motion Stage 2 truck cam (3-bolt), Chevrolet Performance LS7 lifters with BTR beehive springs and moly pushrods. Just finished a 2500 mile camping trip through the northeast pulling our 7500 lb camper, and never ran short on power anywhere. On a few long grades when I had to downshift to 3rd, I had to keep my foot out of it or it'd keep accelerating.

Side note: I have never been able to find a chart or performance data for VVT vs non-VVT at lower RPMs where it's supposed to be most effective, so I'm still skeptical of its benefits outside of fuel mileage. I also have a 2007 XL Denali that still has the stock cam and VVT and the 2012 with the 3-bolt cam will outrun it off the line pulling the same camper, all the way through the rev range. On the same highway entrance ramp near my house, I'm 10 mph faster merging onto the highway with the 2012 than I am with the 2007 when towing. The only significant difference is the cam. And both are Black Bear tuned for premium fuel.

Option 3 is a 5.3 liter vvt cam. Either go option one or 2. If you are going to be tuning it yourself with no prior knowledge, it will be easier with the smaller cam, but that doesn't mean it will suddenly be easy, just a little less work to get it to idle properly. If you want to error on the side of better towing, go with the stage 1. If you want capable towing with a little more upper end power, go the stage 2. With the 6 speeds it isn't a problem finding the correct range to be in If it is tuned correctly to not lug shift like they do stock. You should be shifting a 6 speed at 2 grand at light throttle for each gear for best economy, not lugging it down as fast as they can get it into 6th, like factory. You will never have a problem towing with the stage 2 if it's tuned properly. Just leave the converter unlocked until 5th, and have it shift at 2 grand through all gears, and it will pull like a champ. And of course watch your tranny Temps, and do an aux cooler installed before the factory cooler if it needs one. Being in Michigan you will want to run the tranny fluid through the stock rad location to warm it up in the winters.

Okay sounds good thanks so much you’ve been incredibly helpful getting this narrowed down, So I reached out to black bear and they’re willing to do it for about the cost of a HP tuner so for simplicity sake I think ill hit the easy button and let them do it. I’d like to go with the stage 2 but it mentions something about recommending a 2800+ stall and there isn’t much meat left in the budget for a 1k$ circle d. My boats really light it’s a 17ft Lund pro angler the truck pulls that thing around like there’s nothing back there. I really just want something that’s got a noticeably aggressive attitude with street manners.

 

[hagar]

Okay sounds good thanks so much you’ve been incredibly helpful getting this narrowed down, So I reached out to black bear and they’re willing to do it for about the cost of a HP tuner so for simplicity sake I think ill hit the easy button and let them do it. I’d like to go with the stage 2 but it mentions something about recommending a 2800+ stall and there isn’t much meat left in the budget for a 1k$ circle d. My boats really light it’s a 17ft Lund pro angler the truck pulls that thing around like there’s nothing back there. I really just want something that’s got a noticeably aggressive attitude with street manners.

Great!! I know for a fact you will be super happy with it. Enjoy!

 

[j91z28d1]

Okay sounds good thanks so much you’ve been incredibly helpful getting this narrowed down, So I reached out to black bear and they’re willing to do it for about the cost of a HP tuner so for simplicity sake I think ill hit the easy button and let them do it. I’d like to go with the stage 2 but it mentions something about recommending a 2800+ stall and there isn’t much meat left in the budget for a 1k$ circle d. My boats really light it’s a 17ft Lund pro angler the truck pulls that thing around like there’s nothing back there. I really just want something that’s got a noticeably aggressive attitude with street manners.

just thought I might mention if it's the 6 speed.. it seems from reading here it's always a good idea to replace the stock converter. they have thin clutches or something that when they go, it takes the tranny with it. so a converter is considered preventive maintenance. so incase you're in the fence. check the tranny threads?

 

[hagar]

Great!! I know for a fact you will be super happy with it. Enjoy!

Just make sure you give the blackbear guy the tsp cam position numbers they supply so he can plunk them in

 

[JPS0284]

Great!! I know for a fact you will be super happy with it. Enjoy!

Thanks! Should I be concerned about the stall if I went with the stage 2 and having Black Bear tuning it? If it were your truck which of the two would you choose?

 

[JPS0284]

just thought I might mention if it's the 6 speed.. it seems from reading here it's always a good idea to replace the stock converter. they have thin clutches or something that when they go, it takes the tranny with it. so a converter is considered preventive maintenance. so incase you're in the fence. check the tranny threads?

Thanks for the advice, maybe I should just stage 1 it then or just baby for awhile . I plan doing the cam swap header and y pipe over the course of a weekend I don’t know if I could handle pulling the trans in that short of a time. I do plan on getting a 2800ish circle D soon after my wallet recovers from bleeding to death.

 

[hagar]

Thanks! Should I be concerned about the stall if I went with the stage 2 and having Black Bear tuning it? If it were your truck which of the two would you choose?

I always choose the stage 2, haven't even done a stage 1. Pretty sure they either recommend the stall for the issue I brought up before about how it pushes through the converter, it was a pain in the ass to dial in the first time, but works well after figured out. That or they just do it as a blanket statement for any stage 2 cam. There is ZERO hesitation or waiting for the power to come on with a stock converter and the stage 2. The truck fully weight transfers at launch, it feels more like a screw type supercharger power than a big cam power.
That being said, 90 percent of the gains will be accomplished with the stage 1, there is no shame in going with the stage 1 and erroring on the safe side.

 

[JPS0284]

I always choose the stage 2, haven't even done a stage 1. Pretty sure they either recommend the stall for the issue I brought up before about how it pushes through the converter, it was a pain in the ass to dial in the first time, but works well after figured out. That or they just do it as a blanket statement for any stage 2 cam. There is ZERO hesitation or waiting for the power to come on with a stock converter and the stage 2. The truck fully weight transfers at launch, it feels more like a screw type supercharger power than a big cam power.
That being said, 90 percent of the gains will be accomplished with the stage 1, there is no shame in going with the stage 1 and erroring on the safe side.

Thanks I appreciate your honesty, I’ll go with the stage 1 then. Now that’s settled, I originally set down this path to do a AFM delete on my L94, do I need to swap out oil pumps I heard something about needing to block passages in the sump? I think goetrash had it in his list when he did his swap.

 

[hagar]

Thanks I appreciate your honesty, I’ll go with the stage 1 then. Now that’s settled, I originally set down this path to do a AFM delete on my L94, do I need to swap out oil pumps I heard something about needing to block passages in the sump? I think goetrash had it in his list when he did his swap.

Vvt engines run a higher pressure pump than non vvt, that is why people change them out when deleting. That being said, it depends on the mileage on your engine. Anything over 60k, I would change it while I was in there. You can do it without pulling the pan, just need to lower it down and fiddle F,ck you fingers in there to get at the bolt. Just pack the opening with clean towels incase you drop the bolt. Also, don't change to the dog bone tensioner like is common, I just replace with a new gm tensioner assembly. The vvt systems don't like the play in the traditional dog bone conversion a guy does when doing a cam.