2.7 Turbo 4 Fan Club

Low Elevation · July 24, 2023

13 minutes ago, 4banger said:

did you have 2022 refresh?

No, I had the 22 ' Limited.

4banger · July 25, 2023

On 7/24/2023 at 9:25 AM, Low Elevation said:

No, I had the 22 ' Limited.

ok thanks, I haven't driven the non-refresh original tune, was just curious as my refresh has gobs of power and could not imagine wanting or needing more, you have to let off the pedal real quick if you stomp it off the line (like you were late on a green light) before that boost kicks in or tires start spinning, and just the overall acceleration, I've given many v8's fits and won many little drags, and even new diesels, I like telling them at next lights I only have the four banger and that's with my 400 lb fuel tank and 585 lbs of adds/tools etc. always onboard, would have an absolute riot with a reg cab shorty in 4 hi empty, would be a potent little dragster imo, if the plate of said hypothetical truck said 4bangr even better lol

although the tuner guys who dyno'd an early refresh sure didn't see a giant torque number so have some speculation maybe the older tune motors were making it into the early refreshes also despite that all things I could find ensured that wouldn't be the case...I might have to go drive a newer 2023 to see for sure though, if I have the older tune and am this happy then wow...I have a feeling that can't be the case though

gm keeps advertising 430 ft/lbs though so maybe that's not an easy measure for the regular dyno shops dynos to capture accurately? there is a mystery there yet to be solved, I'm sure as we see more guys dyno things between the year classes we will be able to tell which is which and maybe why they aren't showing 100 plus ft/lb higher torque figures than their hp figures as that should be the case on the refresh for sure if considering a 15-20% driveline loss...the gap should still be 100 plus ft/lbs

Edited July 25, 2023 by 4banger

fondupot · July 27, 2023

Has anyone installed a transmission thermostat bypass kit on their 2.7L equipped truck with the 8L90 trans?

I know M5U 8L90's are compatible with most kits (namely the Superior STL010.) But I haven't found any info if the MQE 8L90 that is in my truck, is compatible.

For reference, my truck is a 2022 LTD, 2.7L Non-HO.

Edited July 28, 2023 by fondupot

silveradosid · July 28, 2023

i have been searching also Dave and come up with nothing

Texcl2 · July 28, 2023

I’m not going to worry about the tranny temp, I haul all sorts of stuff and the tranny temps stay constant whether loaded or not. I know they are higher than what people are used to but that’s where they designed the temps to be. Not to mention it gets down to sub zero often into the -20’s and 30’s, 4 months out of the year here so don’t want over cooling.

Grumpy Bear · July 28, 2023

2 hours ago, Texcl2 said:

I’m not going to worry about the tranny temp, I haul all sorts of stuff and the tranny temps stay constant whether loaded or not. 1.) I know they are higher than what people are used to but that’s where they designed the temps to be. 2.) Not to mention it gets down to sub zero often into the -20’s and 30’s, 4 months out of the year here so don’t want over cooling.

1.) And what part of the "design" changed that enabled them to run that high without consequences? Nothing! Seals, gaskets and adhesives used to bond clutch linings are the same. The fluid has changed. Oxidation initiation temperature of the base oil has improved slightly. Carrier oil for the add pack has not. Viscosity continues to go down and temperatures continue to rise which does what? Reduce viscosity even further. What does viscosity do? Keep parts from touching parts. High temperature varnishing of the valve body is still an issue and will be along as lubricant is carbon based.

The "Design" criterion has shifted from longevity to economy. On paper the difference between the viscosity of Dexron III and HP is a few centipoises and mathematically improved economy. In practice it does nothing of the sort. The OEM concern for longevity runs out at the end of warranty.

GM 8-Speed 8L90 M5U Transmission Info, Specs, Wiki | GM Authority

From this link: The 8L90 uses Dex 6 HP Transmission fluid, which was developed to have a more consistent viscosity profile as well as improved lubrication characteristics.

Translation of "More consistent Viscosity". Less variation in viscosity aka a tighter lighter spec and less shift under use.

Translation of "Improved Lubrication Characteristics: Is less hygroscopic. Not quite what it sounds like, is it?

2.) Thermostatic control is a NEWER technology. Pre 2014 it's pretty much nonexistent.

Question. On a -30F day when you start up what is the temperature of the fluid? Yea, it shifts a bit funny in the winter until it heat up over 85F / 30C. All automatics do. The fluid heats from work and it will get over 104 F like it has for the last 60 plus years.

Unless your area gets colder that -40C/-40F you have no worries.

Grumpy Bear · July 28, 2023

3 hours ago, Texcl2 said:

I know they are higher than what people are used to.

People get 'Used to" allot of things. Like paying $2 for a nickel candy bar. :crackup:

People are funny. Give this a look. Mineral Oil in this graph is straight cut like pre-1970-ish. A current Group III, like what GM fluids are made from act more like their close cousin PAO (Polyalphaolefins). People hear a PAO will take 280F! and as you can see that number is plucked from the end of the bar in red. Not in the Yellow Continuous use area. What does that mean? Note the Red bar starts JUST past the point mineral oil fails. It' only 20 degrees more capable than the mineral oil. Yea, PAO will take 280 F for a few minutes. Not continuous service!

Marketing loves its lies. People buy them retail.

4banger · July 28, 2023

I've been watching for an image or video of the new 'turbomax' badging but haven't seen a thing yet....anyone seen a turbomax badge anywhere yet on the new 2023's or Colorado/canyons?

newdude · July 28, 2023

23 hours ago, fondupot said:

Has anyone installed a transmission thermostat bypass kit on their 2.7L equipped truck with the 8L90 trans?

I know M5U 8L90's are compatible with most kits (namely the Superior STL010.) But I haven't found any info if the MQE 8L90 that is in my truck, is compatible.

For reference, my truck is a 2022 LTD, 2.7L Non-HO.

Its internal to the transmission valve body. No cooler lines on the 8L90 with the 2.7 like the V8 trucks had to have an external TBV. 2.7 8L90 has an oil to water (and air) heat exchanger bolted to the transmission side so ATF in and out on one part of the cooler, engine coolant in and out the other part. The Active Thermal Management (that fancy electric water valve) can direct more cooling if needed to parts of the system including the transmission cooler to regulate temperatures.

Edited July 28, 2023 by newdude

Grumpy Bear · July 28, 2023

2 hours ago, newdude said:

Its internal to the transmission valve body. No cooler lines on the 8L90 with the 2.7 like the V8 trucks had to have an external TBV. 2.7 8L90 has an oil to water (and air) heat exchanger bolted to the transmission side so ATF in and out on one part of the cooler, engine coolant in and out the other part. The Active Thermal Management (that fancy electric water valve) can direct more cooling if needed to parts of the system including the transmission cooler to regulate temperatures.

Because simple didn't work!

fondupot · July 30, 2023

On 7/28/2023 at 1:20 PM, newdude said:

Its internal to the transmission valve body. No cooler lines on the 8L90 with the 2.7 like the V8 trucks had to have an external TBV. 2.7 8L90 has an oil to water (and air) heat exchanger bolted to the transmission side so ATF in and out on one part of the cooler, engine coolant in and out the other part. The Active Thermal Management (that fancy electric water valve) can direct more cooling if needed to parts of the system including the transmission cooler to regulate temperatures.

Thanks for the input. I didn't know the trans was that much different from the V8 equipped trucks. Is that what the difference in RPO codes is for?

M5U 8L90's is for V8 trucks with the external bypass?

MQE 8L90's is for 2.L trucks with internal cooling system as you described above?

newdude · July 31, 2023

23 hours ago, fondupot said:

Thanks for the input. I didn't know the trans was that much different from the V8 equipped trucks. Is that what the difference in RPO codes is for?

M5U 8L90's is for V8 trucks with the external bypass?

MQE 8L90's is for 2.L trucks with internal cooling system as you described above?

M5U was last gen.

Both 2.7 and 5.3 versions of the 8L90 for 19-21 (and current for 2.7) are MQE. The 5.3 MQE has the external TBV on the lines at the side of the transmission.

Texcl2 · August 1, 2023

So who has the most miles on a 2.7? There has to be some folks with 150k+ by now, right?

fondupot · August 4, 2023

On 7/31/2023 at 10:38 AM, newdude said:

M5U was last gen.

Both 2.7 and 5.3 versions of the 8L90 for 19-21 (and current for 2.7) are MQE. The 5.3 MQE has the external TBV on the lines at the side of the transmission.

Got it thanks for clarifying.

4banger · August 18, 2023

will be fun to watch the 2.7 in the colorado/canyons to see how the mpg's stack up on fully.com

I'm super curious about that low tune model to see how fleet/retired guys do on mpgs, should be a durable and economic winner regardless of tune. Looks like 2 mpg advantage shown here.

https://gmauthority.com/blog/2023/03/2023-chevy-colorado-4wd-fuel-economy-ratings-with-l3b-engine-revealed/#:~:text=Now%2C GM Authority has exclusively,17%2F21%2F19 mpg.

but I can achieve rated hwy mileage with my truck with 4" lift, chin spoiler removed, and 985 lbs added to it at 70 mph so will be interesting to see true empty running with the little truck and the retired guy tune!