2024 Sierra Denali top speed limiter ?

[Big_Kahuna]

I have a two question 

can anyone comfort what is the top speed limiter set on the 2024 Denali ? my at4 cut out at 112 

and do 2024 have a active exhaust ?

[GETGONE]

It depends on the tire option as to the top speed cutoff. 2024 the active exhaust is optional. Saw several on the local GMC lot with it as an additional $395 option on the sticker the other night.

[newdude]

NPP active exhaust is available on SLT, AT4, AT4X and Denali, and is standard on Denali Ulitmate.  6.2 engine only.  You will have to look at your build sheet or the window sticker for the option.  

 

Speed limiter will vary.  Wheel/tire combo and more importantly the speed rating on the tire will dictate.  Should be 98mph, 106mph or 112mph.  A trip to "roads in Mexico" will help you find out what it stops at.    

Edited December 26, 2023 by newdude

[typhoon186]

My 2023 denali speed limit kicks in at 106 mph.  That's only 1/4 throttle!.  My factory tires ( bridgestone alenza a/s 02, size   275/50-22) were rated at 118 mph or 130 mph.   Not sure which.  So why is my speed limit so low?  Now I'm on a mission to raise/delete this crazy speed limiter.   If I have to pay the stupid $ to unlock the ecm and buy hptuners credits then I guess that's what I will end up doing.  This is BS.!

[KARNUT]

2 hours ago, typhoon186 said:

My 2023 denali speed limit kicks in at 106 mph.  That's only 1/4 throttle!.  My factory tires ( bridgestone alenza a/s 02, size   275/50-22) were rated at 118 mph or 130 mph.   Not sure which.  So why is my speed limit so low?  Now I'm on a mission to raise/delete this crazy speed limiter.   If I have to pay the stupid $ to unlock the ecm and buy hptuners credits then I guess that's what I will end up doing.  This is BS.!

This topic pops up from time to time. Seems it’s not just tires the drive shaft comes into play. 

[CamGTP]

Exactly, the driveshaft is the main reason why. Once it hit critical speed, bad things will happen.

 

Lots of cool youtube video's of stock trucks from different era's having the driveshaft explode on the dyno at over 100mph.

[typhoon186]

Interesting:   Maybe I was just lucky in my 2014 that was tuned and the limits removed.  I ran it over 130+ mph many times and most all of my previous trucks.   I'm sure it's a rare problem on a modern truck on the highway.  I can see the risk increasing on a dyno or drag strip under a big load.  However, I'm very surprised and skeptical that GM would allow a truck to be produced with such a design limitation when it can easily be designed out from the start.  I can understand a limit based on the tires design since they have no control over that, but not a driveshaft that can be designed well beyond the speed the vehicle can achieve.  And I'm sure there is a huge safety factor built into their design limits as well.    I guess the drive shaft length on a truck vs. a car is the issue but still it could be designed to handle the higher speeds.   Maybe a good idea to add a drive shaft loop if I'm going to raise or remove the speed limit in the future just in case.   

 

Here's a good article about drive shaft failures:

https://www.onallcylinders.com/2015/09/18/ask-away-with-jeff-smith-examining-common-causes-of-driveshaft-failure/

 

 

https://gmauthority.com/blog/2020/11/chevy-silverado-gmc-sierra-recalled-over-driveshaft-separation-problem/

 

 

 

Edited January 20, 2024 by typhoon186

[KARNUT]

1 hour ago, typhoon186 said:

Interesting:   Maybe I was just lucky in my 2014 that was tuned and the limits removed.  I ran it over 130+ mph many times and most all of my previous trucks.   I'm sure it's a rare problem on a modern truck on the highway.  I can see the risk increasing on a dyno or drag strip under a big load.  However, I'm very surprised and skeptical that GM would allow a truck to be produced with such a design limitation when it can easily be designed out from the start.  I can understand a limit based on the tires design since they have no control over that, but not a driveshaft that can be designed well beyond the speed the vehicle can achieve.  And I'm sure there is a huge safety factor built into their design limits as well.    I guess the drive shaft length on a truck vs. a car is the issue but still it could be designed to handle the higher speeds.   Maybe a good idea to add a drive shaft loop if I'm going to raise or remove the speed limit in the future just in case.   

 

Here's a good article about drive shaft failures:

https://www.onallcylinders.com/2015/09/18/ask-away-with-jeff-smith-examining-common-causes-of-driveshaft-failure/

 

 

https://gmauthority.com/blog/2020/11/chevy-silverado-gmc-sierra-recalled-over-driveshaft-separation-problem/

 

 

 

I was surprised myself. I tuned all my trucks. Living in Texas there’s several roads I travel that I stretch the legs of my vehicles. We have roads that are 75 miles per hour that are two lanes. Passing a tractor trailer you can easily exceed 100 miles per hour. I passed with my foot buried. Some of the passing lanes are short you really have to get after it. I’m older and retired I’m not in a hurry anymore my vehicles are older. So rarely get after it. My working traveling days, it was every day. So yeah the drive shaft thing was a surprise.

[typhoon186]

PCM of NC is a very experienced and reputable tuner.  They will not dyno tune trucks for drive shaft concerns but do road tuning and have no problem winding it out speed wise on the road.  Just won't do it on their dyno.  

[Naughty Donkey Performance]

14 hours ago, typhoon186 said:

My 2023 denali speed limit kicks in at 106 mph.  That's only 1/4 throttle!.  My factory tires ( bridgestone alenza a/s 02, size   275/50-22) were rated at 118 mph or 130 mph.   Not sure which.  So why is my speed limit so low?  Now I'm on a mission to raise/delete this crazy speed limiter.   If I have to pay the stupid $ to unlock the ecm and buy hptuners credits then I guess that's what I will end up doing.  This is BS.!

Get a Pulsar LT and you can manipulate top speed, tire sizes for speedo correction, auto start stop delete, DFM delete etc , well worth the $$ considering all you get and easily installed or removed.

 

[Bikerjon]

1 hour ago, Naughty Donkey Performance said:

Get a Pulsar LT and you can manipulate top speed, tire sizes for speedo correction, auto start stop delete, DFM delete etc , well worth the $$ considering all you get and easily installed or removed.

 

Not available for the refresh Silverado 1500 2022 1/2 and up. I just checked.

 

Still waiting...............

[typhoon186]

They said they are working on it but to time frame as of yet.  Follow them on crackbook for the latest updates and product information.