Tuner decell mode
Thread Starter
|
Laughing Gas
Joined: Aug 2003
Posts: 836
Likes: 7
Tuner decell mode
I have had my tuner for well over 10 years and 100,000 miles. My tunes are towing related except one 60hp economy tune (not economical but performance is great)
I have often wondered when using decel mode (exhaust brake) works great but I really don't know how it really works. It sounds like a closed exhaust but I don't know if transmission is involved as well?
on those long sweeping down grades it works awesome but in the back of my mind I wonder if it's safe to use?
Any thoughts?
I have often wondered when using decel mode (exhaust brake) works great but I really don't know how it really works. It sounds like a closed exhaust but I don't know if transmission is involved as well?
on those long sweeping down grades it works awesome but in the back of my mind I wonder if it's safe to use?
Any thoughts?
FTE Chapter Leader
Joined: Jan 2005
Posts: 13,087
Likes: 4,699
From: Henderson, NV
Reading between the lines, I assume you have a DP Tuner on a truck with a 4R100 transmission? How it works is the tuner co-ops the EBPV into becoming an exhaust brake and then locking the torque converter to achieve the deceleration. Some have argued that it may cause valve float due to excessive exhaust back pressure. I have not encountered any issues personally but then again I have uprated valve springs and a BTS transmission..
FTE Leadership Emeritus
Joined: May 2014
Posts: 27,345
Likes: 5,941
From: Lake Hartwell, GA
I had some similar questions a while back and created the thread linked below. I was attempting to educate myself on the built in capabilities of the 4R100 at the time. Maybe it will help you a bit.
4R100 when descending a grade...
4R100 when descending a grade...
Fleet Mechanic
Joined: Aug 2010
Posts: 1,456
Likes: 155
From: Sedalia, CO
Here's a thread from years ago that talks about the valve float (non) issue, and a little bit about how the tune works.
Decel tune - Harmful EBP levels, or not? - Ford Truck Enthusiasts Forums (ford-trucks.com)
Mark
Decel tune - Harmful EBP levels, or not? - Ford Truck Enthusiasts Forums (ford-trucks.com)
Mark
It's a Van Gogh
Joined: Feb 2010
Posts: 7,798
Likes: 1,330
From: Elk Grove, CA
Great info above. I will just add my experience with the DP decel tune has been all positive. In the sense that it retards speed on a long down grade. My 5er was kinda light at 8k#, but a 7% downgrade was fully controlled without hitting the brakes. Trans temp never budged. Engine did not blow up, not even once. 
Thread
Thread Starter
Forum
Replies
Last Post
moeszyslak
1999 - 2003 7.3L Power Stroke Diesel
71
Jan 6, 2010 03:09 PM
