[Logo] GDE Forum - Home for the best in diesel powertrain tuning
  [Search] Search   [Recent Topics] Recent Topics   [Hottest Topics] Hottest Topics   [Top Downloads] Top Downloads   [Members] Member Listing   [Groups] Back to home page 
[Register] Register /  [Login] Login 
Messages posted by: GreenDieselEngineering
Forum Index » Profile for GreenDieselEngineering » Messages posted by GreenDieselEngineering
The bridge area between the valves has the smallest cross section of aluminum. The pressure causes cyclic stresses on the aluminum, the heat is generally slow to respond due to the mass of the head. Coatings are used on the pistons of some performance diesels as a method of heat control and extending piston life.
Based on the machining costs, the price for the first 10 kits will be around $2800. This would include the tune and all hardware to complete the job. It is imperative the CRD is equipped with an aftermarket torque converter. We have tested the turbo kit with the new Mopar TC and it performs wonderfully!
We have several KJ timing belts on hand if anyone needs one. The price is $140 shipped. These are original OEM parts. We will also rent out the timing tools for people looking to complete this job at home. Just call or e-mail us for more details.
There is not a weak point in the block. The weakest link is the bridge area between the ports on the aluminum cylinder head. With the hot tune we measure about 170 bar peak firing pressure at peak torque between 2000 and 2400 rpm at WOT. At peak power (3800 rpm) the pressure is down to about 130 bar. The engine just does not breathe enough at high rpms to increase the system pressure...it will just make more smoke at a certain point and not useable power.

The durability testing on this engine in Europe included several tests where the powertrain was ran for 2000+ hours on a WOT cycle that includes idle time between runs. Each cycle was about 1-2 minutes. This puts the maximum stress on the cylinder head from a cyclic fatigue failure point of view. The test has a very high load factor compared to a real life automotive application. VM does a good job of flogging their engines to the limit to find the weak links.

The on road equivalent of this test would be running 0-90 mph back down to 0 and repeat for the life of the vehicle. Definitely much more aggressive than real life. The constant load of cruising down the highway is much less stressful on the engine even if pulling a trailer.
There are no defined limits for horsepower or torque, it is a function of cylinder pressure during combustion. 160 bar is no problem for this engine and it can handle up to 180 bar for shorter periods of time. The amount of torque produced at a given cylinder pressure depends on how long the combustion event lasts. If the burn lasts for 45 crank angle degrees verses 30 degrees the effective torque may be more. Many different parameters will play into this, but the area under the curve when measuring the cylinder pressure is vital to determine torque. Sorry for the engineering speak. The other limit is turbo speed, 180000 rpm is good all day and the bearings can handle up to 200000 rpm for shorter durations.

With a cast iron cylinder head and studs the engine would be able to achieve upwards of 230 bar and the bottom end should still be fine...unless someone designs a cast head we will never see those numbers.

In the end, you do not want to get too crazy with a 4-cylinder engine as the torsionals get too high and will wreak havoc to the transmission, a 6-cylinder is a much better option for overall driveline life.
We have received the first ten kits and will be sending parts out for machining work. Due to the holiday season we are not expecting to have the completed kits ready for sale until mid to late January. Having the parts in hand is a big step in the right direction and we are working to expedite this as soon as feasible. Thanks for the patience.
A couple days ago we released a slight change to the EVIC calibration. The slope was reduced by about 8%. The effects vary based on driving condition. Here are the limited results we have thus far. In highway cruising the EVIC was reading about 1.5mpg high and in city driving it was reading about 1.0 mpg low, so the end result with mixed driving should be more accurate than stock.

The input for the calculation is a non dimensional fuel flow rate, then corrected with slope factor and finally divided vehicle speed. The flow flow rate is based on the injector flow maps from the factory test bench, these are not accurate at low fuel flow rates, so this messes up the overall accuracy. If the odometer is not reading the same as GPS, the accuracy will also suffer. Even with all this, we think the cal change is directionally correct for having the EVIC reflect reality and not be so biased to the high side.
The turbo is on back order at the moment. We have secured a supplier to complete all the machining work, so we are just waiting for parts. It may take up to January for kits to be available. Sorry for the delay, but once it is ready it will be worth it!
The friction modifier may be a good solution for borderline shudder problems. We noticed that the product comes in a 2 oz tube, did you only need one tube or are several required to acheive the desired effects? Does this mean you are sticking with the HOT tune on the one vehicle?
Good question. It appears to be more pronounced with the hot tune. The rate of decreasing the fuel when releasing the pedal is the same for both tunes, but the hot tune allows 15-20 % more fuel in high load driving. So with the hot tune the decrease to zero fueling takes slightly longer and there is a noticeable difference.

We have spent the last few days working on optimizing the fueling ramping rates based on throttle input. The results are very promising as we have still been able to keep the "clunk" down to a minimum and the vehicle does not feel like there is any surging or positive torque when tipping out of the pedal. This part of the tune is very subjective to feel and 10 differenct customers may have 10 different preferences. The goal is to find the proper balance where no one even notices it...if it is transparent then we did a good job.
The tunes have changed the pedal response significantly. One of the areas we focused on was to minimize the "clunk" in the driveline due to torsional lash wind-up. In order to do this we added filtering to the pedal, which tends to make the response more smooth, but slightly slower.

We would like to get a better understanding of your driving preferences for pedal response (snappy vs. smooth) and the relative importance of driveline clunk...does it matter? Several customers have noted the increased "coasting" with the tune, however, this may be a hinderence for some drivers. This part of the tune can be revisited and it should not effect fuel economy.

This is a democracy so vote early and often! We look forward to hearing your suggestions.

This is true, regardless of the firmware in the ECU. Both our tunes will have the latest glow plug calibration installed. This at least makes sure your vehicle is up to date in terms of glow plug service releases. We updated all our cals on 20 October.
There are no issues if one unplugs the glow plugs, other than the constant CEL. We could turn off the glow plug CEL if customers really wanted it. Down in Texas where you are at, the glow plugs are not used that often and most likely they will not be fully powered in order to acheive the regulating temperature. The northern portion of the US and Canada tend to put the glow plugs through more exercise and would have a higher percentage of failures. Having the latest calibration of the glow plugs is the most important factor as it works to reduce the maximum plug temperature and increase life.

If you had a cold snap in Texas and the ambient dropped down to 15-25 F overnight, the CRD would be very hard pressed to start without the glow plugs operational, unless the block heater was plugged in all night. After starting, the engine may have some misfire for the first 2-3 minutes without glow plugs working. You may want to test this on your vehicle a few cold mornings to see the effects in your region.

It would be interesting to know how many owners have actually had a glow plug issue and what region of the US they are located.
We tried to adjust the curve that controls the instantaneous fuel economy, but there are several inaccuracies in the lower end of the fueling curve. With the GDE tune less fuel is used and it operates more at the lower end of the inaccurate fueling curve, thus making the EVIC read slightly higher fuel economy. The software is very limited here.
The Body Controller is a separate computer from the engine contoller and that TSB will have no effect to the tune. We are going to take more measurements in the coming days and then look into the TSB stutus on our 06 vehicle. Minimizing the leakage rate will only extend battery life.
Forum Index » Profile for GreenDieselEngineering » Messages posted by GreenDieselEngineering
Go to:   
Powered by JForum 2.4.1 © 2015 JForum Team • Maintained by Andowson.com