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BMW Diesel Owners / Enthusiasts
Do you own a diesel powered BMW? Maybe a 335d or a BMW x35d? Come and talk about what makes your car great! |
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#76
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Re walnut blasting -- Replacing a head is less expensive??? I thought I remember some member stating it was a couple of grand to replace their head had they needed to pay for it outside of warranty. Walnut blasting is only a few hundred bucks. |
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#77
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I'm sorry to do this, but going back and looking at some other data shows something that complicates the EGR data I posted yesterday . . .
The attached is from Feb of this year (pre recall) on a very long road trip. It was recorded with the Android Torque app at 5 sec intervals. The EGR behavior appears to vary with the DPF loading. The data for the drive started with a fairly fresh DPF condition. The data shows the car doing a DPF regen around the "1700" time points where the EGR is very low for ~10 mins. Note that the closer the car gets to DPF regen time the lower the EGR utilization. And after the regen the EGR rate increases to heavy utilization. I also included the "engine load" and "speed" parameters to show the similarity in operating conditions as those things can also impact EGR. So with the previous data I posted I'm not sure of the DPF condition for the "pre recal" EGR example for that mornings drive to work. The "post recal" behavior is on a recently regenerated DPF which means it's similar to the behavior in this graph. So basically I'm retracting the conclusion I made that the EGR behavior is significantly different. Sorry for the confusion . . . |
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#78
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While the overall average EGR duty may be the same, still looks like it is operating in a more full open/full closed manner rather than maintain partial opening for extended lengths of time. But then were all guessing.
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#79
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Spent some time this weekend with the GTech device to analyze launching traction issues that seemed potentially helpful to others. Also, there was some additional tweaking on the above car this weekend. The progressive JBD mod was further tweaked (to reduce low rpm distortion to below "0" level to minimize peak low rpm torque, and push the distortion further into the rpm and take the peak distortion to the ~100% level to further enhance top end power) as well as running 50/50 water/methanol (recently added an AEM flow meter and the car is sucking ~650ml/min at peak fueling).
The GTech device shows some very interesting effects on the launching procedures. Below is 4 seperate runs with various brake boosted launching rpm's and fueling procedures. Additonally two runs had the rear street tires at 41psi and two at 33psi. 3 had DCT on, 1 had all traction control off. It's neat to see the impact of these variables on the G forces and speeds. Obviously the lower psi on the tires helps with traction, and it also appears this car needs to not be floored immediately as the tires can't handle the traction at the two psi settings that were examined. Further reduction in psi, or using drag radials should improve the traction to a point where more fuel can be applied sooner for better 60' launches. Also thought the Black vs Green run was interesting. The green had a better 60' time, but because the tires lost traction, and no traction control algorithms were used to cut back pwr, the 330' time was actually worse. Also, used the Black run (3rd gear portion) to compare to the earlier recorded hp/tq curves using the previous JBD/H2O injection setup. The torque curve is pushed further into the rpm range and provides for nearly 20more hp from 3400-4400 rpm. It's probably not quite that much as the temps were a lot cooler this weekend, although it was into a 10mph headwind . . . |
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#80
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By any chance do you have data for Evolve alone? I might have missed it. Last edited by cssnms; 10-08-2012 at 06:22 PM. |
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#81
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Hmmm, perhaps I can clear up some potential area's where the data, or presentation of the data, wasn't clear.
Important points: The best comparisons of various combo's will come from looking at the data collected on the same day with the same fuel and at the same ambient temps on the same roads with the same winds and same DPF loading and same heat soaked engine conditions (before the H2O/methanol injection this aspect had more effect and could skew results ~10hp). That's a lot of different variables right there even before looking at the different power adder combo's. And there's a lot of different combo's in this thread. So, the post with the first quote above (page 2 post #27) was with 70F and no wind, stock vehicle with the JBD at 0, ~65 and ~85%. Those results were ~214, 237, 253 hp and 363, 378, 402 ft-lb. No comparison without the JBD. Post #40/41 shows a comparison of stock vs JBD at 0 and 65%. These were done back to back, so relative to each other they should be pretty close, but not necessarily a great comparison to the post #27 data. This comparison showed ~209, 221, 241hp and 351, 368, 381 lb-ft (slightly more than the #27 data for the JBD at 0 and 65). So the JBD at 0 seemed to add ~12 hp above stock and the JBD at 65% added ~32hp with the GTech hp/tq measurement on this day. Post #49 starts with the Evolve evaluation. There's several caveat's given for why direct comparisons's to previous data needs to be considered. The general summation I gave was this: "But here’s the summation of the hp/tq #’s. The JBD @ ~85% produced similar TQ #’s as the remap, but a bit better HP. Now it might be that the tank of Illinois fuel in the vehicle has lower cetane or BTU’s than what was in the vehicle for the previous tests. Don’t have a way to test that. " On this same post it's noted that the stack of the Evolve remap with the JBD at 65% produced ~30hp increase over the remap alone. The curves on post #51 (the tq curves for the remap/JBD stack are not accurate due to not giving full fuel at low rpm's to avoid excessive low rpm torque) show ~ 33.5 hp increase for ~65% and just a few hp for the 0%. However, the remap only data was from a different day/fuel/temp/etc, so an absolute comparison isn't valid. However, what is valid to say is the delta increase of the remap with the JBD follows a very similar trend as that from post #41. The last quote you put up is from post #52 and includes #'s from post #51 as well as #'s from a different day/fuel/environment condition. The new data showed ~19hp increase from the 0-65% JBD setting instead of the ~30hp from previous data groups. However it was a warmer day and heat soak could've been involved in skewing those #'s for the 65% test, which was performed a few mins after the 0% run. Clear as mud? |
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#82
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Also noticed something interesting on the launch data from this weekend. Comparing the HP vs time data to the RPM vs time data, it appears to me the optimum time to do the 2-3 shift is ~ 4300rpm, which is before the car shifts itself (hp is droping fast at the 3.1 sec point but the shift doesn't happen until ~3.6 sec). Also note how much less peak hp is applied to the ground in 2nd than 3rd (more drivetrain loss due to fluid coupling of the TC, and then it locks up in 3rd, might be less boost in 2nd also, haven't looked at that).
The driver was letting up on the skinny pedal at ~4400 rpm at the end of the 3rd gear range which is why the HP is falling off at time ~6.4 sec. However, it might also prove beneficial to do the 3-4 shift a little earlier as well... |
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#83
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Did some experimenting with drag slicks yesterday. Significantly easier to control the launch with these and much better 60' and 0-60mph times. Attached is a comparison of 2 of the better street tire launches vs the 2 runs performed with the DR's. Looks like the initial brake boosted rpm's could be increased further and the rate of moving the skinny pedal to the floor could be increased for further improvement.
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#84
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http://www.bimmerfest.com/forums/sho...9&postcount=33
Broke into the 12.6's with a trap speed of 109.7 today. |
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#85
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An oil sample was pulled this weekend to examine impact of stacked tunes with water/methanol injection. This oil was Mobil 1 5w-40 ESP and had ~6700 mls on it. Seems pretty good.
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#86
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Are you using the Castrol from the dealer?
__________________
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#87
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Dealer supplied oil for all but the last one. Did a mid-cycle change over to the Mobil 1 5w-40 ESP for the hot summer months.
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