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QUIKAG

Why Does My 6.2 Denali Short-shift

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I read my '08 makes 380hp at 5,500rpm or so. Well, if my truck is shifting at 5,400rpm, I'm not even close to making peak power or acceleration. I've seen Escalade videos that show the motor winding up past 5,700rpm.

 

Is this how GM rated my motor at 380hp and the Escalade at 403hp? When I shift manually (with the buttons), I can wind it up to nearly 6,000rpm. In Drive, it seems to upshift always around 5,400rpm.

 

See a vid I made testing out a K&N FIPK when I had it on the truck and let me know your thoughts about the upshifting at 5,400rpm or so:

 

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You need to get Justin from Black Bear Performance to tune your truck. My 6.2L rips till 6k and 6,100 using the manual thumb paddle.

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Are you racing the NHRA circuit or something? Mine shifts at like 2500-3000 in normal city driving.

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Are you racing the NHRA circuit or something? Mine shifts at like 2500-3000 in normal city driving.

 

 

Coming from a guy who is enhancing the performance of a 1976 VW Bus, that is funny. I'm just sayin'.....

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The higher the revs the shorter the longevity of the engine GM set the redline and shift points for a reason.

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hell yeah pushing it that hard is asking for a short run on the motor...you do realise that the numbers they release does not factor drivetrain lag or the rest of the variables?

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you guys are nuts.. I made over 250 passes in my LS2 equipped TBSS running in the 11's (on 125 shot, 12.5s NA) and that engine still purred like a kitten when i traded it in.. i f an eingine's gonna break it's gonna break.. NA, boosted engines, tuned, different story.

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you guys are nuts.. I made over 250 passes in my LS2 equipped TBSS running in the 11's (on 125 shot, 12.5s NA) and that engine still purred like a kitten when i traded it in.. i f an eingine's gonna break it's gonna break.. NA, boosted engines, tuned, different story.

 

and i bet the guy that bought what you traded in is paying your repair bills now...the effects of abuse don't show over night pal...my old truck was beat to snot and rarely got oil changes before i got it and once i began doing regular maintance on it the aftermath of womping on it showed...just my two cents

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If I paid for 380hp, then I should have the option of using it without manually shifting it. This 6.2L motor can take a lot of abuse and I only rev it up or run it hard a few times a week. Rest of the time it's upshifting before 2,000rpm most of the time.

 

These motors can take a lot more than you guys think. We're talking the difference between 200k miles and 250k miles of durabililty between someone who granny drives versus hot rodding it.

 

You should see the abuse I put my '08 Corvette through at track days. That LS3 motor is sent to hell and back every weekend and I don't anticipate any engine issues for years. GM knows what they are doing with these small-block motors.

 

So, back to my original question. Why is the motor upshifting at such a low rpm, one that is even lower than THEIR ADVERTISED horsepower peak? I know an aftermarket tune will fix this and I have a tune on my Vette, but I just don't want to tune my truck for a multitude of reasons.

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If I paid for 380hp, then I should have the option of using it without manually shifting it. This 6.2L motor can take a lot of abuse and I only rev it up or run it hard a few times a week. Rest of the time it's upshifting before 2,000rpm most of the time.

 

These motors can take a lot more than you guys think. We're talking the difference between 200k miles and 250k miles of durabililty between someone who granny drives versus hot rodding it.

 

You should see the abuse I put my '08 Corvette through at track days. That LS3 motor is sent to hell and back every weekend and I don't anticipate any engine issues for years. GM knows what they are doing with these small-block motors.

 

So, back to my original question. Why is the motor upshifting at such a low rpm, one that is even lower than THEIR ADVERTISED horsepower peak? I know an aftermarket tune will fix this and I have a tune on my Vette, but I just don't want to tune my truck for a multitude of reasons.

 

man, you need a tune. to all the nay-sayers out there, this is my second LQ4 6.0 now with a tune. i had both tuned, any vortech engine LOVES to rev. if its gonna break its gonna break, my truck now hangs 1st till 5700 RPM. 2nd gear to 5300 RPM at WOT. by the time its out just gettin out of second, its screaming! and im doin about 145km/h. the last motor i had i had it mated to a nv3500 had rev limit set at 5800 also. put 200k kms on that motor stilll never burnt any oil, ran like a top. its a chevy you guys, they'll last. especially the vortech's, love to rev.

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If I paid for 380hp, then I should have the option of using it without manually shifting it. This 6.2L motor can take a lot of abuse and I only rev it up or run it hard a few times a week. Rest of the time it's upshifting before 2,000rpm most of the time.

 

These motors can take a lot more than you guys think. We're talking the difference between 200k miles and 250k miles of durabililty between someone who granny drives versus hot rodding it.

 

You should see the abuse I put my '08 Corvette through at track days. That LS3 motor is sent to hell and back every weekend and I don't anticipate any engine issues for years. GM knows what they are doing with these small-block motors.

 

So, back to my original question. Why is the motor upshifting at such a low rpm, one that is even lower than THEIR ADVERTISED horsepower peak? I know an aftermarket tune will fix this and I have a tune on my Vette, but I just don't want to tune my truck for a multitude of reasons.

 

To answer your question directly: GM Engineering decided that the shift point of 5400 on the 6.2 and the 6L80E/6L90E combo was the best. Their advertised number is what the engine CAN do but WILL NOT do due to the trans. Trans is the weaker point and GM felt 5400 was the best option given their knowledge of the drivetrain. It DOES suck but that was an engineering decision. Not sure if you are looking for anymore than that but I doubt you will get it - short of an actual GM Drivetrain engineer chiming in.

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Are you racing the NHRA circuit or something? Mine shifts at like 2500-3000 in normal city driving.

 

 

Coming from a guy who is enhancing the performance of a 1976 VW Bus, that is funny. I'm just sayin'.....

 

 

Point taken. :(

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If I paid for 380hp, then I should have the option of using it without manually shifting it. This 6.2L motor can take a lot of abuse and I only rev it up or run it hard a few times a week. Rest of the time it's upshifting before 2,000rpm most of the time.

 

These motors can take a lot more than you guys think. We're talking the difference between 200k miles and 250k miles of durabililty between someone who granny drives versus hot rodding it.

 

You should see the abuse I put my '08 Corvette through at track days. That LS3 motor is sent to hell and back every weekend and I don't anticipate any engine issues for years. GM knows what they are doing with these small-block motors.

 

So, back to my original question. Why is the motor upshifting at such a low rpm, one that is even lower than THEIR ADVERTISED horsepower peak? I know an aftermarket tune will fix this and I have a tune on my Vette, but I just don't want to tune my truck for a multitude of reasons.

 

To answer your question directly: GM Engineering decided that the shift point of 5400 on the 6.2 and the 6L80E/6L90E combo was the best. Their advertised number is what the engine CAN do but WILL NOT do due to the trans. Trans is the weaker point and GM felt 5400 was the best option given their knowledge of the drivetrain. It DOES suck but that was an engineering decision. Not sure if you are looking for anymore than that but I doubt you will get it - short of an actual GM Drivetrain engineer chiming in.

 

 

I'm sure that is the correct answer. I know GM did it for a reason, but it's still a little bit annoying that they hogtied the motor to not make it's full potential power. It didn't seem to slow them down on the Escalade where the shift points seem to be 5,700rpm or thereabouts and it has the same 6L80 transmission. Might be a feeble attempt to keep the Yukon from being faster than the Escalade? I wonder if the new Yukon Denali which makes the full advertised 403hp winds out a bit more? Any Sierra or Yukon Denali owners with an '09 or newer? What is the shift point at full throttle through the first few gears?

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I'm sure that is the correct answer. I know GM did it for a reason, but it's still a little bit annoying that they hogtied the motor to not make it's full potential power. It didn't seem to slow them down on the Escalade where the shift points seem to be 5,700rpm or thereabouts and it has the same 6L80 transmission.

 

Might be a feeble attempt to keep the Yukon from being faster than the Escalade? Yes

 

I wonder if the new Yukon Denali which makes the full advertised 403hp winds out a bit more? NO

 

Any Sierra or Yukon Denali owners with an '09 or newer? Dont Know

What is the shift point at full throttle through the first few gears? Dont Know

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I'm sure that is the correct answer. I know GM did it for a reason, but it's still a little bit annoying that they hogtied the motor to not make it's full potential power. It didn't seem to slow them down on the Escalade where the shift points seem to be 5,700rpm or thereabouts and it has the same 6L80 transmission.

 

Might be a feeble attempt to keep the Yukon from being faster than the Escalade? Yes

 

I wonder if the new Yukon Denali which makes the full advertised 403hp winds out a bit more? NO

 

Any Sierra or Yukon Denali owners with an '09 or newer? Dont Know

What is the shift point at full throttle through the first few gears? Dont Know

 

 

Wonder what the difference is between the 380hp motor and the 403hp motor? Still a little peeved the motor doesn't make the full advertised horsepower at the programmed shift points from the factory. That's pretty weak. Blaming the 6L80 tranny isn't the right answer as this transmission is also used on the Corvette which winds out all the way to 6,500rpm with the LS3 motor.

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