Welcome to Modern Mopar Forum

Register now to gain access to all of our features. Once registered and logged in, you will be able to contribute to this site by submitting your own content or replying to existing content. You'll be able to customize your profile, receive reputation points as a reward for submitting content, while also communicating with other members via your own private inbox, plus much more! This message will be removed once you have signed in.


8HP70 trans won't shift 1-2 on nitrous.

Hi guys. I've got a ram 1500 5.7 8 speed with bolt ons and nitrous. I was having a problem when I turned the nitrous up where it wouldn't shift the 1-2. It would blow past the shift and hit the limiter and go into limp mode. 

Now I have tuned the transmission with HP tuners, all shifts are firm and quick when NA. On the bottle, once again, no 1-2 shift. It no longer hits limp mode due to me raising the rev limit in the TCM. But it will ride the engine limiter at 6400 and stay there until I pedal it. It is not spinning when this occurs. I tried adjusting everything I could think of in the trans tune to no avail. In the end, I had to turn the nitrous controller down to just 40% off the line to get it to shift. 


Anyone have any experience with the 8 speed tuning? Any power adder 8 speeds having trouble? 

Share this post

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now