2.7 Turbo 4 Fan Club

newdude · January 27, 2023

Alright 2.7 fanboys/fan gals. The kind folks and Chevrolet have blessed us with a new video on the 2.7 HO.

The 1:27 mark offers up some much desired information. A torque chart! Which is in comparison to the 2.7 EcoBoost I might add.

The engineer in the video, Kevin Luchansky also states that at 1500rpm the HO makes 350 torque, as evident by the chart above. So the HO still gets that 1500rpm nice hit but then doesn't stop. From 2000rpm to 3500rpm the HO provides 400 or more torque across that band.

Seeing this chart finally solidifies the thoughts I've gathered over the almost 11,000 miles I've put on mine, in that it hits a high number quick, climbs beyond that and then eventually drops back off. Its all meat from 1500rpm and probably to 4000rpm just like the non HO but offers up that extra sauce in the middle.

Mike Borowski · January 27, 2023

Sounds about right. I’ve driven a HO and have 25,000 on my original 2.7. The HO basically just feels stronger a little longer.

Grumpy Bear · January 27, 2023

Now if they could keep a ring seal. :nonod:

4banger · January 27, 2023

12 hours ago, newdude said:

Alright 2.7 fanboys/fan gals. The kind folks and Chevrolet have blessed us with a new video on the 2.7 HO.

The 1:27 mark offers up some much desired information. A torque chart! Which is in comparison to the 2.7 EcoBoost I might add.

The engineer in the video, Kevin Luchansky also states that at 1500rpm the HO makes 350 torque, as evident by the chart above. So the HO still gets that 1500rpm nice hit but then doesn't stop. From 2000rpm to 3500rpm the HO provides 400 or more torque across that band.

Seeing this chart finally solidifies the thoughts I've gathered over the almost 11,000 miles I've put on mine, in that it hits a high number quick, climbs beyond that and then eventually drops back off. Its all meat from 1500rpm and probably to 4000rpm just like the non HO but offers up that extra sauce in the middle.

Yes, that's what I thought I bought. Pretty sure normal dyno's will show us a 15-20% drop at the wheel in that corrected crank hp/torque info always provided by manufacturers.

So the peak hp and torque from the 2022 refresh custom the tuner dyno'd was 255 his and 262 ft/lbs torque. Can the engineers explain that? Why is there only 7 ft/lbs more torque than hp from a regular shops dyno but the manufacturer can show us 120 ft/lbs more torque than hp? The tuner who dyno'd that truck should have seen a torque curve 100 ft/lbs higher than what they got...what gives? Even the gen 1 tune should have shown at least a 40 ft/lb gap....NOT a 7 ft/lb gap!

Mike Borowski · January 27, 2023

Getting old-school folks over the “4 cyl in a truck” thing is the only hurdle this engine has. The thing is great. Do I miss the sound of a V8? YES! But otherwise there is 0 incentive to choose the 5.3L.

Since most truck owners these days use it as a family hauler and for trips to Home Depot, it’s a perfect engine for them.

newdude · January 27, 2023

1 hour ago, 4banger said:

Yes, that's what I thought I bought. Pretty sure normal dyno's will show us a 15-20% drop at the wheel in that corrected crank hp/torque info always provided by manufacturers.

So the peak hp and torque from the 2022 refresh custom the tuner dyno'd was 255 his and 262 ft/lbs torque. Can the engineers explain that? Why is there only 7 ft/lbs more torque than hp from a regular shops dyno but the manufacturer can show us 120 ft/lbs more torque than hp? The tuner who dyno'd that truck should have seen a torque curve 100 ft/lbs higher than what they got...what gives? Even the gen 1 tune should have shown at least a 40 ft/lb gap....NOT a 7 ft/lb gap!

Are you talking about Burger Motorsports? The dyno chart clearly has the truck listed as a 2021 in which case the power represented would agree with the non HO. The torque curve is the giveaway in the chart that they used a non HO for the baseline.

I don't buy that chart being tied to a 2022 HO if that's the claim they are making. I own an HO and have driven non HO. My butt dyno says there's no way at all that chart is from an HO baseline.

Edited January 27, 2023 by newdude

Grumpy Bear · January 27, 2023

52 minutes ago, Mike Borowski said:

But otherwise, there is 0 incentive to choose the 5.3L.

Simplicity? Efficiency?

When they say "A more efficient design"; they are not referencing the motors' ability to use fuel efficiently. They are referencing the most efficient way to get X lb./ft. torque. It is a nature of the design that allows this power on slightly less fuel. Sounds like hair splitting I know.

In the days of the flathead if you needed more power, you added displacement. When the OHV motors arrived the 'design' allowed more power from the SAME displacement making it a more efficient air pump. As time toddled on, they learned to make the OHV a more efficient combustor. Increased compression. Vortec heads. Juggling bore/stroke ratio and so on but the point is the motor made more power from less fuel from the SAME displacement. It's power density increased, and its fuel efficiency followed the improvements in combustion dynamics. By the time we reach the 21 century we have small displacement V6's and V8's making the power of 7-to-9-liter 8- and 10-cylinder motors of a few decades before on a fraction of the fuel. As a bonus the reliability and longevity of these motors increased as well. If they were to follow the natural path 'Free Valve" motors would be next and propel combustion efficiency well past the 50% mark only Mercedes-Benz race motors enjoy today. The unwillingness of the OEMs to follow this path is the wind pushing electrification.

While a turbo motor is a more efficient air pump, in that it decreases pumping losses, it does not automatically make it a more efficient combustor. It's primarily a means of increasing displacement artificially. Getting a 2.7-liter motor to make the power of a NA 6 liter. This kids, causes cooling issues as combustion efficiency does not follow power improvement and now......it gets complicated. Rings seal, a thing I preach is not keeping up with power density.

This is just the OEMs getting the most power from the CHEAPEST package that will last just long enough to keep expectations in check and keep Uncle Sam's wolves away long enough to complete the transition to batteries.

We have the technology to do better it just isn't profitable.

Grumpy Bear · January 27, 2023

I expect this motor will indeed by my next motor. Likely in a Colorado. It's just sad, that's all.

Mike Borowski · January 27, 2023

22 minutes ago, Grumpy Bear said:

Simplicity? Efficiency?

When they say "A more efficient design"; they are not referencing the motors' ability to use fuel efficiently. They are referencing the most efficient way to get X lb./ft. torque. It is a nature of the design that allows this power on slightly less fuel. Sounds like hair splitting I know.

In the days of the flathead if you needed more power, you added displacement. When the OHV motors arrived the 'design' allowed more power from the SAME displacement making it a more efficient air pump. As time toddled on, they learned to make the OHV a more efficient combustor. Increased compression. Vortec heads. Juggling bore/stroke ratio and so on but the point is the motor made more power from less fuel from the SAME displacement. It's power density increased, and its fuel efficiency followed the improvements in combustion dynamics. By the time we reach the 21 century we have small displacement V6's and V8's making the power of 7-to-9-liter 8- and 10-cylinder motors of a few decades before on a fraction of the fuel. As a bonus the reliability and longevity of these motors increased as well. If they were to follow the natural path 'Free Valve" motors would be next and propel combustion efficiency well past the 50% mark only Mercedes-Benz race motors enjoy today. The unwillingness of the OEMs to follow this path is the wind pushing electrification.

While a turbo motor is a more efficient air pump, in that it decreases pumping losses, it does not automatically make it a more efficient combustor. It's primarily a means of increasing displacement artificially. Getting a 2.7-liter motor to make the power of a NA 6 liter. This kids, causes cooling issues as combustion efficiency does not follow power improvement and now......it gets complicated. Rings seal, a thing I preach is not keeping up with power density.

This is just the OEMs getting the most power from the CHEAPEST package that will last just long enough to keep expectations in check and keep Uncle Sam's wolves away long enough to complete the transition to batteries.

We have the technology to do better it just isn't profitable.

Ok I’ll give you repairability.

Mike Borowski · January 27, 2023

32 minutes ago, newdude said:

Are you talking about Burger Motorsports? The dyno chart clearly has the truck listed as a 2021 in which case the power represented would agree with the non HO. The torque curve is the giveaway in the chart that they used a non HO for the baseline.

I don't buy that chart being tied to a 2022 HO if that's the claim they are making. I own an HO and have driven non HO. My butt dyno says there's no way at all that chart is from an HO baseline.

Burger clarified it was a HO they had on the dyno.

KARNUT · January 27, 2023

In the last 8 years since retiring I go on the same trip 3-4 times a year. Texas to Fayetteville NC. I’ve used 4 different vehicles. 3 are higher fuel mileage vehicles and are still in the family. Hyundai Geneses, Toyota Camry and the CRV. At 72 miles per hour they all generally get around 27 miles per gallon. The Genesis performance numbers are about equal to my trailblazer ss. It’s a large quiet, very sedate cruiser. The Honda in contrast is loud busy cruiser. I’ll keep driving the CRV because I’m cheep. If my mother in law hadn’t quit driving and gave us the CRV. I would blissfully be tripping the Genesis till it died. I could see myself driving a maverick type GM small pickup with that 4cylinder. The TQ is made low enough only if it’s a non CVT. All that with a stick. I’d order it right now.

Edited January 27, 2023 by KARNUT

customboss · January 27, 2023

14 hours ago, Grumpy Bear said:

Now if they could keep a ring seal.

So far my oil usage has stopped @3200 miles with a Havoline 5w-30 PRO-RS DEXOS1 GEN 2 level of additives. Fingers crossed. I romped on my first gen L3B yesterday passing someone slower than me.....LOL and hit 90 mph abeam the semi truck from 58 mph start WOT. I love this thing. Then after passing the slower vehicle slowed back to my 65 MPH speed limit drive back from VA.

Edited January 27, 2023 by customboss

622Trailboss · January 29, 2023

On 1/27/2023 at 1:33 PM, customboss said:

So far my oil usage has stopped @3200 miles with a Havoline 5w-30 PRO-RS DEXOS1 GEN 2 level of additives. Fingers crossed. I romped on my first gen L3B yesterday passing someone slower than me.....LOL and hit 90 mph abeam the semi truck from 58 mph start WOT. I love this thing. Then after passing the slower vehicle slowed back to my 65 MPH speed limit drive back from VA.

Just wondering if you have experimented with a tonneau cover related to your mpg? I plan to switch to either BFG KO2s or Nitto Ridge Grapplers once my Duratracs need replacing. The duratracs are roughly 20lbs heavier and it reducing 80 lbs of rotational mass should do wonders for mpg and acceleration.

Mike Borowski · January 29, 2023

25 minutes ago, 622Trailboss said:

Just wondering if you have experimented with a tonneau cover related to your mpg? I plan to switch to either BFG KO2s or Nitto Ridge Grapplers once my Duratracs need replacing. The duratracs are roughly 20lbs heavier and it reducing 80 lbs of rotational mass should do wonders for mpg and acceleration.

I love my Toyo AT3’s FYI and they are about 10lbs less than the K02’s

Edited January 29, 2023 by Mike Borowski