I love my new 2013 Durango R/T with one exception. The relatively poor job Dodge did with matching the 6 speed transmission with the high rpm power curve of the hemi engine. When you have an engine that develops max torque at 4250 RPM and max HP at 5100 rpm, that's a fairly high and narrow power band. The transmission needs to have close gear ratios to maximize the power curve. The 6 speed transmission on this vehicle has very wide gear spacing with the most noticeable between 3 and 4 gear. I suspect the 2014 8 speed has addressed this problem. However, the top gear seems just too high for this car. Pulling a 2.5 ton AWD vehicle down the freeway at 1600 - 1800 RPM when max torque is in the 4,000 RPM range causes this engine to lug, sputter, and stumble at freeway speeds. I'm sure this was done to help the fuel economy ratings and I'm also assuming this is a characteristic of this vehicle, not a specific problem with mine. And, I could be a little more in tune to these things than some drivers. I find myself dropping the transmission to 5th and even fourth gear where the engine runs much smoother at an rpm range above 2000 RPM. OK, with that background, now to my questions. Anyone know of an aftermarket solution to the gearing/power curve issue through an ECU swap, chip, or other solution? Also, is it possible to lower the overall final drive ratio and if so, how difficult?

 

Well a tuner can eliminate most of the torque mangement, which I feel causes a sharp decline in the vehicles performance from 2nd-4th gear.

Are you using tow haul mode?

If so, your solution is the same as mine. When going up steep inclines for a distance, or if I am pulling a heavier load than my boat, I drop a gear and ride over 2K RPMS as the HEMI favors that position with the 6 speed.

 

Diablo claims their canned tunes take care of this. As fish said the puter is really detuning the output of the motor with timing curves etc.
Also make sure to run 89 gas, it may seem silly but regular gas just doesnt work great with these. When the knock sensor detects anything at all from low grade or poor gas it retards timing fiercely to protect itself.
STEVE

 

I feel your pain, the D has much more potential. Try a top tier 89 fuel and tow haul mode. I took the D drag racing and was doing the quarter with 1st and 2nd gear only, shifiting into 3rd after I crossed the line. I too am interested in a custom tune in the future.

 

I still like my Hypertech which helps in faster downshifting and better accelerator response. I still feel a large improvement over stock, which to me, was hardly drivable.

I may go with diablo and a good tune in the future after that has been proven to be an improvement in the 2013 durangos reliably. For me, the hypertech helps this problem at the cheapest price and easiest install.

Let the flaming begin!

 

I'm curious, what do you mean by proven reliability? I haven't seen or heard of any issues from tuners or hypertech that cause an issue with reliability.

 

Rhino.. the hemi makes plenty of torque, over 160 ft-lbs at idle and over 250 ft-lbs at 2500rpm. Its torque peak is higher like 90% of current v8 engines simply because it needs to make Horsepower (which raises TQ peaks, remember the old 5250 rpm protocall from autoshop) and have a wider overall power band. If you would like to install a TQ cam they make a few of them for our application. This will bring your tq peak down to say 2900 rpm but you will destroy the engines ability to rev and lower horsepower above 3800rpm. Its a give and take with the ram truck version of our engine way better suited to low speed pulling power having a dual stage intake manifold that increase runner length at low speed thereby increasing low rpm torque. We can not fit this intake on our vehicle. I am working on getting the gearing problem solved next year by installing the hemi rams 3.92 axle ratio but waiting for bugs to get fixed on the diablo or another manufacturer to solve the TQ management issue while also offering PCM gearing change programs.

 

Tuner is the way to go. Chrysler boggs down all it's engines with excessive torque management. I believe with the DS you hit peak torque somewhere in the neighborhood of 2k RPM. I know you reach max torque @ 1950 RPM with the Pentastar 3.6 and a DS tune (stock @ about 4400 RPM).

 

Hypertech and 89 gas it will all go away. I took off my hypertech due to my Durango needing a dealer visit and haven't put it back on yet. Very noticeable decline in how its running.

 

Hey guys, thanks for the lead on the Hypertech Interceptor. I didn't want to go with a full tune due to possible warranty implications until later in the cars life. But the plug-and-play features of the Interceptor seem like the ticket.

Mikeon22's, from your comments, I'm assuming there's no evidence of the Interceptor being installed after it is removed?

Fullslp, any idea on the cost to install the 3.92 axle ratio?