Need Some Opinions

[msj724]

I am new to the forum world, but I wanted to see if others feel their Tahoe/Yukon is underperforming. I know this is a big car, and I don't expect it to drive like my Trailblazer SS did, but I feel like it is a slug sometimes. Just yesterday I turned right at a light that was already green so I didn't have to stop all the way. After completing the turn I gave it some gas, and I felt no pull (torque) whatsoever. I pressed the gas a little more, and all I got was this flat acceleration. It felt like I was in fourth gear at 20 miles an hour trying to accelerate, and there was no upshift in gears. Almost like I was driving one of those cars with a CVT tranny. I feel like with the exhaust, CAI, and tuner I should not be having this problem. I know I am an aggressive and this is not an aggressive car, but it's not some old lady's car either (no offense). I am in talks with Justin at BB tune to see if he can make a difference. Any opinions? Maybe I am expecting too much out of a big car.

Thanks for the input!

 

[rogersinsel]

Have you considered running a performance test? Zero to 60 times should be in the 8 second range, perhaps faster with what you've done.

 

[iwaslowr]

I am new to the forum world, but I wanted to see if others feel their Tahoe/Yukon is underperforming. I know this is a big car, and I don't expect it to drive like my Trailblazer SS did, but I feel like it is a slug sometimes. Just yesterday I turned right at a light that was already green so I didn't have to stop all the way. After completing the turn I gave it some gas, and I felt no pull (torque) whatsoever. I pressed the gas a little more, and all I got was this flat acceleration. It felt like I was in fourth gear at 20 miles an hour trying to accelerate, and there was no upshift in gears. Almost like I was driving one of those cars with a CVT tranny. I feel like with the exhaust, CAI, and tuner I should not be having this problem. I know I am an aggressive and this is not an aggressive car, but it's not some old lady's car either (no offense). I am in talks with Justin at BB tune to see if he can make a difference. Any opinions? Maybe I am expecting too much out of a big car.

Thanks for the input!

What pinion gear ratio does your Tahoe have? A ratio less than 3.42 (like 3.08 or 3.23) could be one factor. Even with 3.42's my Yukon seems weak below 3000RPM in the scenario you gave... adding 33 inch tall tires made it a little worse.

Increasing the gear ratio may help... but what may be easier is upgrading to a higher stall converter to help bring the engine into your preferred power range at lower speeds. Installing a Yank TT3000 converter in my 2002 Silverado with 3.73's drastically improved acceleration from slow speeds as well as from complete stops.

 

[Sepiroth]

If you do not have a strategy or protocol to remove the torque management, what you felt was most likely, that kicking in.

When you get on the throttle over a predicted amount, torque management kicks in to save the drivetrain from what it thinks is abuse or driving that would be detrimental to it.

 

[PavementPounder]

If you do not have a strategy or protocol to remove the torque management, what you felt was most likely, that kicking in.

When you get on the throttle over a predicted amount, torque management kicks in to save the drivetrain from what it thinks is abuse or driving that would be detrimental to it.

 

[msj724]

Thanks for the feedback everyone! I will look into your advice.

---------- Post added at 11:52 AM ---------- Previous post was at 11:51 AM ----------

A custom tune from BB may be able to deal with the torque mgmt for me, wouldn't you think?

 

[Sepiroth]

Yes, provided that in the custom tune, that was specified.

But do not treat what I replied with as Gospel. One time I thought it was torque management when something similar happened to me on a Trailblazer I once owned.

It turned out to be a defective mechanical cooling fan clutch.

 

[msj724]

Noted...Thanks!

 

[iwaslowr]

I was under the impression that TM only affected power during the process of shifting between gears and also for a few seconds shortly thereafter... Perhaps I have been misinformed.

 

[Conor]

I would recommend getting in touch with Justin at BlackBear Performance. Not only can he make you a custom PCM that will seriously out perform your stock one, but he can also diagnose any issues you may be having that would be causing the lack of power. These new generation Tahoe’s are so limited down from the factory that even a little tweaking of the PCM can make a huge difference in performance as well as mpg.

One quick question for you. Have you noticed a decrease in mpg? That is usually the best indicator if you have an engine issue. Good luck, and again I HIGHLY recommend a BlackBear tune.
www.blackbearperformance.com