2.7 Turbo 4 Fan Club

Dunn · January 14, 2020

25 minutes ago, CTB said:

95% of the time spent in whatever truck I buy, will be commuting. 60/40 highway/city. 22 miles one way. 5% of the time I’ll be pulling a camper that weighs just under 4000lb loaded. Considering the previous, purchase price is one of the biggest factors going into my decision. My only concerns are; how relatively new this engine is and how many problems the 8 speed has had over the years. I plan on driving this truck for at least 10 years.

I go back and forth daily between ordering a custom trail boss with the 6.2/10spd and finding an rst with the 2.7. If the 2.7 came with the 10 spd I wouldn’t be nearly as reluctant.

yeah its perfect for a lot of people, I just don't understand why it was stock motor is all

Grumpy Bear · January 14, 2020

2.7 Turbo power is a weeee bit greater than the Ecotec3 4.3 on E85. 5 hp. and a few pounds/feet more torque. The 2.7 comes with the lower geared 8 speed. The T1 has a new frame that is suppose to be all that and a bag of chips. Yet when I look at the tow and payload ratings the 4.3 on 87 octane still out pulls and out hauls the 2.7 buy a few hundred pounds in both. In theory the motor claims a bit more city mileage and about the same highway numbers. In practice ????? Doing less with more?

Other that the fact that you can get the 2.7 in nicer trim levels I'm confused as the point of this motor.

Educate me.

L86 All Terrain · January 14, 2020

2 minutes ago, Grumpy Bear said:

2.7 Turbo power is a weeee bit greater than the Ecotec3 4.3 on E85. 5 hp. and a few pounds/feet more torque. The 2.7 comes with the lower geared 8 speed. The T1 has a new frame that is suppose to be all that and a bag of chips. Yet when I look at the tow and payload ratings the 4.3 on 87 octane still out pulls and out hauls the 2.7 buy a few hundred pounds in both. In theory the motor claims a bit more city mileage and about the same highway numbers. In practice ????? Doing less with more?

Other that the fact that you can get the 2.7 in nicer trim levels I'm confused as the point of this motor.

Educate me.

I can't answer your question, but could it be that the turbo 4 outweighs the V6 with its turbos and intercooler taking away a couple hundred pounds of payload? Seems odd to offer both of these engines being so close statistically. Seems very odd you can spec the V6 to move more with the 6L trans vs the 4cyl with the 8L trans.

heymrdjCW · January 14, 2020

2.7 Turbo power is a weeee bit greater than the Ecotec3 4.3 on E85. 5 hp. and a few pounds/feet more torque. The 2.7 comes with the lower geared 8 speed. The T1 has a new frame that is suppose to be all that and a bag of chips. Yet when I look at the tow and payload ratings the 4.3 on 87 octane still out pulls and out hauls the 2.7 buy a few hundred pounds in both. In theory the motor claims a bit more city mileage and about the same highway numbers. In practice ????? Doing less with more?

Other that the fact that you can get the 2.7 in nicer trim levels I'm confused as the point of this motor.

Educate me.

2.7 has better driveability because the 4.3 takes over double the RPMs to make its torque. Much of the US outside of the Midwest doesn’t have easy accessibility to E85, so it’s kind of silly to use the numbers like your average every day driver is pumping that.

My guess is the limitation on towing comes from maxing out the intercooler, where as a 4.3L doesn’t need one. In the real world, there won’t be any difference in the use case for either engine.

I personally believe that the 4.3L will be phased out for a gen 2 2.7 eventually. They don’t make much sense in the stable together. I do think GM made a mistake going for 4 big cylinders instead of 6 smaller ones on the design. I think a 2.7 6 banger would have delivered better MPG. Either way, having driven both quite a bit now, I wouldn’t take a 4.3.

zzrsouth · January 14, 2020

1 hour ago, Grumpy Bear said:

2.7 Turbo power is a weeee bit greater than the Ecotec3 4.3 on E85. 5 hp. and a few pounds/feet more torque. The 2.7 comes with the lower geared 8 speed. The T1 has a new frame that is suppose to be all that and a bag of chips. Yet when I look at the tow and payload ratings the 4.3 on 87 octane still out pulls and out hauls the 2.7 buy a few hundred pounds in both. In theory the motor claims a bit more city mileage and about the same highway numbers. In practice ????? Doing less with more?

Other that the fact that you can get the 2.7 in nicer trim levels I'm confused as the point of this motor.

Educate me.

The turbo offers more usable torque at low revs. Most apparent when climbing a mtn pass. NA engines struggle or have to turn high revs whereas the turbo just tractors up in top gear.

KARNUT · January 14, 2020

So the V-6 has the capability to get great fuel mileage with cylinder deactivation to make it a 4 cylinder. The 4 cylinder has a turbo to have the the power of a V-6. There’re playing with us. A few years ago you could get an E-85 capable 5.3 and get close to the 6.2 in power. Now they can go all the way down to one cylinder. I’ll keep watching till they figure it out. It is entertaining though.

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Grumpy Bear · January 15, 2020

5 hours ago, zzrsouth said:

The turbo offers more usable torque at low revs. Most apparent when climbing a mtn pass. NA engines struggle or have to turn high revs whereas the turbo just tractors up in top gear.

In top gear? Up a mountain pass? At full rated towing weight? Really? I suppose at the speed limit too?

Oh I have got to see the video on that run!

Where can I find it? Got a link?

CTB · January 15, 2020

30 minutes ago, Grumpy Bear said:

In top gear? Up a mountain pass? At full rated towing weight? Really? I suppose at the speed limit too?

Oh I have got to see the video on that run!

Where can I find it? Got a link?

MDSilveradoGuy · January 15, 2020

16 hours ago, Grumpy Bear said:

In top gear? Up a mountain pass? At full rated towing weight? Really? I suppose at the speed limit too?

Oh I have got to see the video on that run!

Where can I find it? Got a link?

Not that I am going to engage you on this again, but let's see a 4.3 do what you are stating above. It can't, no engine can. Now, review the video above to see it operating as designed... which if you were to run neck and neck with your beloved 4.3 you would see it get its ass handed to it...

12% more torque and a broader, flatter torque curve where it matters...

Grumpy Bear · January 15, 2020

It makes sense that the new kid on the block actually took my request seriously an did not assume I was looking for a fight.

I thank you CTB (whoever you are). I was given the information I asked for without all the forum drama. Excited I looked that site over for a test of the 4.3 Ecotec3 and found none. I'm not devoid of common sense however and have no illusions that the 4.3 will do the IKE in 8 minutes flat. I've climbed that hill hundreds of times with NA motors.

All that said and as impressive as the video is it did not 'tractor' up the IKE in high gear. It spun 6 K and finally pulled down to 4.8 K or so and it didn't do it in high gear as claimed. By the hype I was expecting a speed limit assault at 2500 rpm in high gear. Thus my amazement. It was truly that simple.

zzrsouth · January 16, 2020

I didn't say anything about towing, that is your thing. I want my truck to do my thing which is 70mph+ up WA state passes with my family in the cab and my bike in the bed and getting good city mpg for commuting to work. And my truck does my thing great.

KARNUT · January 16, 2020

I don’t believe any engine 6-8-10 speed combo is going to stay in its highest gear lugging up a hill. The whole point of the exercise is to use the highest gear possible in its TQ range. While keeping the RPMs as low as possible using the least fuel at the desired speed. Lugging like a tractor wouldn’t accomplish that. Even with no load. Driving awhile with stick would teach a person that.

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Grumpy Bear · January 16, 2020

3 hours ago, KARNUT said:

I don’t believe any engine 6-8-10 speed combo is going to stay in its highest gear lugging up a hill. The whole point of the exercise is to use the highest gear possible in its TQ range. While keeping the RPMs as low as possible using the least fuel at the desired speed. Lugging like a tractor wouldn’t accomplish that. Even with no load. Driving awhile with stick would teach a person that.

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Bingo!

zzrsouth · January 16, 2020

I realize I'm wasting my breath but for the silent thread watchers these charts show why my 2 7T truck tractors up Steven's pass.

The 4.3 V6 is the bottom curve but it's the same for most NA powerplants that make max torque up at high rpms. The 2.7T is at max torque at 1500 rpm. As I am not accelerating or dragging a 6k pound trailer my truck never shifts as the grade increases it just adds fuels to produce more torque at the same rpm.

Turbo engines can be setup for torque or top end hit. As MDSilverado has said multiple times GM went for torque. The engine runs out of breath well before the rev limiter but it doesnt matter because it doesnt need to turn 4k to make enough torque to maintain 70mph up a grade and that's why its awesome. I think the differences are magnified at partial throttle settings where we all operate 99% of the time.

The concept is probably foreign if you haven't driven a small diesel or other forced induction engine tuned for torque which is why there are so many doubters and haters. But Im tired of people coming to our thread asking for explanations and then telling us we dont know what we're talking about.

Drive the truck and decide for yourself. I think most will love it.

This is my 3rd turbo vehicle and I'll never go back.