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Messages posted by: GreenDieselEngineering
Forum Index » Profile for GreenDieselEngineering » Messages posted by GreenDieselEngineering
The TCU is in charge of what engine speed/vehicle speed/pedal position dictates the upshifts/downshifts and when to lockup the torque converter (partial lockup isn't available for this application). However, the engine ECU is in charge of how much torque to allow at those various load points. This is how we can allow either "full torque" while in lockup, or our modified tables which eliminate the shudder while in lockup at the applicable load points.

Regarding the boost, the maps available on the Garrett website are only applicable to the wastegated version of the GT2056 and don't apply to the KJ's VGT version since it has different trims, A/R's, and wheel diameters. For VGT applications (and all turbo families for that matter), it's important to pay respect to three main constraints: compressor outlet temperatures, turbine inlet/outlet temperatures, and rotational speeds. For this application, the wide-open throttle performance is limited by the turbocharger speed - if you exceed the rated speed for too long then the turbo will self-destruct; however, the same goes for the temperature limitations especially in trailer-towing conditions.

The boost setpoint has been optimized at all engine points to provide the best fuel economy, which translates to both the lowest BSFC at each point and the lowest CO2 output. If you raise the boost setpoint too high in normal driving and thus close the vanes too much, then the engine has to work harder to force the air out through the turbine housing and the fuel economy goes down; conversely, if the boost setpoint is too low, there isn't enough air in the cylinder for complete combustion and fuel economy goes down and the engine smokes. Tuning for peak fuel economy isn't as simple as cranking the boost up all the way and going to town, each operating point must be optimized independently.

We spent considerable time in altitude earlier late spring/early summer to maximize the turbocharger performance in altitude. The tradeoff with higher altitude conditions is that with air of lower density, the turbocharger spins faster for a given boost setpoint so we have to pay respect to these limitations when tuning the boost system. At a given altitude, the boost setpoint was adjusted to give the maximum speed permissible so that performance would suffer as little as possible. This is mainly an issue at WOT throttle and load points slightly less, in normal driving we are able to mostly maintain the sealevel performance for boost and fuel economy.

Our tune (regardless of power level) at WOT from sealevel through 12000' is able to maintain a PR between slightly over 3 at sealevel to down to 2.7 at higher altitudes.

We currently have the new torque converter on order but thus far they are on backorder and should be available mid-september.
We cannot change any transmission behavior, but the engine will produce significantly more torque. The TCU is not sending torque signals on our vehicles. The customer can specify if one wants full torque in "lock-up" or just partial torque if using a stock converter.

We modify the code to raise or lower boost setpoint, which drives the vacuum level at the turbo.

For this tune we focused on maximizing the turbo speeds in WOT conditions running close to the surge limit and following to the peak speed line. In normal driving, the turbo is tuned for maximum efficiency zones that provide the best fuel economy. The fueling tables have several breakpoints and cover the full engine operating range. We only change the parts of the code that can be deciphered.

The euro TC part number is: 68037142AA. It is our understanding that this converter can be ordered through a dealer or mopar online (less $$$). The converter is on back order until 13 September at this point in time.
Today we are releasing the "HOT" Tune for customers with an aftermarket torque converter. This product maintains all the fuel economy advantages of the standard ECO tune, however, it has increased power during wide open throttle (WOT) accelerations. The hot tune does have more visible smoke at WOT, but minimal smoke in just about every other operating condition.

We are not recommending this tune for customers with the stock converter as the tune does not carve out torque availability while the transmission is in "lock-up", what you ask for with the throttle is what you get. This tune causes shudder in lock-up with stock transmission and is not directionally correct for torque converter longevity.

The "HOT" tune is priced at $550 for new customers and $50 for customers looking to upgrade from the base ECO tune. All orders need phone confirmation prior to purchase, so please call with any questions or to order the hot tune.


Moving to the hot tune from the base ECO tune will cost $50 and this is mainly to cover the shipping costs. We would not recommend purchasing the hot tune unless you already have an aftermarket torque converter installed. The hot tune will cause shudder with the stock converter. We will have an announcement regarding the availability of the hot tune later today on the forum.
Unfortunately we do not have a source for the engine controllers at a reasonable price. New ECUs must be ordered through Mopar. The 2005 CRD ECU lists for $652 at a dealer and online for $450. The 2006 CRD ECU lists for $725 at a dealer and online for $500. We do have a few units on hand that could be sold to customers as needed for about $300 each and the tune would add another $550 to that. What is your reasoning for wanting a spare ECU? It is a very expensive part to have laying around. We could also prepare an ECU with the tune for your vehicle and have you ship the original back to us after installing the tuned ECU, this would prevent any downtime on your vehicle. We will do our best to accommodate you either way.
A turbo timer is not feasible with the tune. The software needs to change to incorporate this feature. It would need to be a standalone feature. It would just be cheaper and easier to leave the engine running for about 30 seconds at idle before turning it off, this is only needed after running at heavy loads and should not be an issue in normal driving conditions.
We could create a video detailing the timing belt swap as one of our vehicles is also nearing the 100k point. The biggest expense for us will be purchasing a video camera for the task. Are you aware of what a dealer will charge for belt replacement?
Since our Paypal account has limits to its flexible pricing, we are posting discounts for customers that want to purchase multiple tunes. The pricing is as follows and a customer must call and place a phone order to qualify for the pricing:

1 tune $550
2 tunes $1000 9% savings
3 tunes $1450 12% savings
4 tunes $1900 14% savings

This is a good way to team up with a friend or family member to realize additional savings with the GDE tune!
For those customers who are already running the GDE tune and wish to upgrade to this running change (or any other subsequent release in the future), you are welcome to do so. You simply need to let us know if/when to expect your ECU and cover the costs of the return shipping to you with no other expenditure on your part (just get it here and get it home).
During the course of our development, we continue to improve upon various areas that we find to further improve upon the customer driving experience. As of Monday, July 27th 2009, we released what we call a “V2 Running Change” calibration that takes upon the GDE cal and adds further improvements to enhance the customer’s feedback. This process is similar to the OEM environment where as further refinements are made, they’re released to the customer after subsequent validation and verification. All ECU modules received on or after this date will receive our latest V2 calibration.

In addition to what you might have read and/or researched about the GDE tune, you’ll notice the following additional enhancements:
___•Fuel gauge linearization: The original fuel gauge display was biased towards the full side so that it would remain there longer, giving the customer the false realization that you were hardly using any fuel. We have modified the fuel linearization so that between full and ¼ tank, the gauge will (within a few percent error) display the actual volume in the tank not including the 2 gallon reserve. Hence, if you were to fill up at ¾ tank, it should hold (20gal capacity – 2 gallon reserve) * .25 = ±4.5 gallons, 9 gallons at 50% gauge reading, so on and so forth. We did this based on customer complaints that the fuel gauge was horribly inaccurate.
___•Off-road driveability in 4-LOW: While the T-case is in 4-low, we found that raising the idle speed from 760rpm to 800rpm allowed the vehicle to very slowly climb a parking curb without the use of the accelerator. Based on our testing, this resulted in a much more effortless off-road drive. Additionally, the accel pedal torque map was revised for the 4-low setting to allow for a more linear application of torque while driving in inclement terrain.
___•Vehicle driveability governors: This is just a refinement of our previous settings to have the drivetrain “clunk” less during aggressive tip-out maneuvers, especially in 3rd gear lockup.
For those living in Europe, you should be able to purchase the JK torque converter for use on the KJ. Jeep may not allow the warranty over there, at least until the part is officially released for service, not sure about it. Ask a dealer directly or ask for a unit as a spare so they don't question what you will be putting it in. The torque converter kit part number is 68037142AA and includes four bolts to mount the converter to the flexplate.
The torque converter must be purchased through Mopar and it is still not available for purchase in the US. If all the components become available, we could do complete installs for customers. We certainly recommend upgrading the TC with the turbo kit. This would allow you to have 30-35% more torque in lock-up leading to improved fuel economy while towing, less shifting on hills, improved passing, etc.
The "hot tune" has increased top end performance and it will allow maximum torque with the torque converter in "lock-up" mode. Even with the maximum trailers loads pulling in lock-up should not be an issue. No protection mode would be necessary for converter life. If shudder becomes evident in a vehicle, we can always back down the torque in specific cases.
Now that is funny! Far be it for us to use marketing to lure customers in...stock KJ 0-60 mph in 12 seconds. Stage II KJ 0-60 mph in 8.5 seconds and still improving...it is like buying a new vehicle for a fraction of the cost and still achieves an average of 28-30mpg overall. We had the KJ in 4WD part time at a launch with brake torque and all 4 tires spun!

We don't need no thought control...
On our 2006 KJ we installed a set of BFG All-terrain 245/70R16 and the fuel economy dropped about 2.5-3 mpg. We are seriously contemplating a second set of rims (as you know) to get a set of e-rated tires for summer use. The e-rated tires should increase fuel economy up to 2 mpg over stock. It would be nice to hear other mileage comparisons from KJ owners that changed tires.
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