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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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Aside from making the right connection, I know that also to get the torque from an e9x LCI the shop has to have the latest dyno software. Call Dan at Mach V, they have a dyno jet and they pulled torque figures from at least 2 335d's. (571) 434-8333
Last edited by cssnms; 04-30-2012 at 06:45 AM. |
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#77
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DTUK...what kind of results have people seen such as 0-60 1/4 mile etc...
does anyone know of there is a remap available for this (I hate the speed limiter at 135 mph) thanks!! |
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#78
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Renntech's website to me read like their re-flash did away with the 135 mph speed limiter on the non sport cars. I do not know if that is really the case or not since never contacted them.
__________________
--Aaron |
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#79
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I just called Lenny @ RENNTECh to confirm this from Snipe, will keep u guys posted Im also curious since I did the 1/2 run @ 130 mph with wind gusts of 25 mph aginst me, hopefully next time I break at 140 mph. Look me up a www.sneakyclub.com January 2012 Event click "RESULTADOS" (Translation RESULTS) and look for Alex Hernandez the ONLY 335d clocked @129.68, the guy under me with 335i had the latest JB configuration and was upset I beat him BUUYYAAAA!!
![]() Here's the link: http://www.sneakyclub.com/3-er-evento/resultados/ Last edited by Axel61; 04-30-2012 at 08:11 AM. Reason: Added more info and corrected info |
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#80
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Hey guys,
Too lazy to read the whole thread but if you have any JBD related questions feel free to ask. During development we started with a 2 sensor system, and then a 4 sensor system. The 2 sensor was fuel pressure and MAP, but we found MAP alone would not allow boost control on the 335D and X5D. This required the MAF signal and a boost solenoid signal. With those 4 sensors we could then remap boost in addition to fuel. But found very little gains at higher boost levels. So decided to offer the simpler and less expensive fuel pressure only option which has proven to be rock solid reliable over around 1000 diesels we've tuned so far. It's very possible the DTUK is running a more aggressive fuel curve and produces 10hp more, etc, but I would be dubious of 30hp+ difference posted based on our testing. If there really is 30hp+ in there that we're not getting with the JBD we'll go release a JBD_2 for you guys with the 4 sensor control. |
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#81
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Double post.
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#82
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Long time no talk. For the JBD we used the dynojet at specialtyZ. You can not compare results from that dyno to another, especially a non-dynojet, as they will vary greatly. If you'd like to get together again at specialtyZ I'd be happy to pay for a dyno comparison of the systems. The JBD is a quick install easy to use type product so we've never been going for the most power with it. But if there really is something else out there making 30hp+ more (which I doubt) even if the install is more involved I would be very happy build a better mouse trap for you more serious guys. We're also working on a D meth kit currently.
Last edited by Terry @ BMS; 04-30-2012 at 09:31 PM. |
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#83
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Also, regarding performance, it's highly unlikely any D tune is putting out much more than 340rw on a dynojet. The highest I've seen was a JBD @ 330rw. Most of our customers report 300-315rw. Do not make the mistake of trying to compare dyno A to dyno B as they all read and report very different numbers. Last edited by Terry @ BMS; 04-30-2012 at 09:29 PM. |
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#84
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Also the dyno results for the DTUK was performed at a setting that sounds virtually unusable since it puts the car into limp mode more often than not. |
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#85
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#86
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How can running the same fuel pressure settings as the JBD and 10 more psi of boost not yield much more in the way of power? It seems to me what we are missing is a tune that pushes the boost envelope a bit more. Most of the fuel good fuel boxes used by the diesel truck crowd are making BIG power by not only increasing fueling but also by increasing boost. |
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#87
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#88
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#89
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I could see the small turbo being perhaps close to peaked out in what it can provide as more power. I'd think more is left in the big turbo. Of course don't forget if there is something left in them then does the rest of the system support it. I have seen olde factory turbo cars you can ramp up the boost on but the intercoolers and exhausts really caused some issues at that point.
__________________
--Aaron |
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#90
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That's a good observation regarding the smaller turbo. I don't know the specs, but one would think BMW wouldn't slap in a turbo that is operating at or near it's max capcaity, but who knows. It's the smaller turbo that kicks in first right? So one would think running call it 10psi more on that bigger turbo in the upper RPM/speed range would result in some nice HP increases where the diesel even with the JBD could really use it since the car's power tends to drop off in the upper gear range after 60 mph.
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#91
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That said I'm not sure how a sequential setup works with cranking up the boost. Perhaps the smaller unit does become enough of a restriction to not allow the larger turbo to reach it's full potential.
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#92
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For some reason I have in my head this is a compound boost setup. The first turbo kicking in at near idle conditions and feeding into a larger turbo to pre spool it and allow it to kick in lag free once needed. Is that how it is or are they separate? Regardless the smaller turbo is for the low rpm range and why I think added boost there really is not going to show much at all for power. The "lack" of higher end HP I do not think is from lack of boost but nature of diesels. My friends built up Powerstroke still lacks higher rpm power.
__________________
--Aaron |
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#93
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Good point about the sequential set-up. Without knowing the details of how the 4 sensor system would work, I theorize that a box like the JBD that does not reprogram the ecu is probably not sophisticated enough to bifurcate the boost pressure of the two turbos so that it can run different boost settings for each turbo. Maybe it's not even possible w/an ecu reflash. Last edited by cssnms; 05-01-2012 at 06:51 AM. |
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#94
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The lack of upper end power while it is the nature of how diesel engines work coupled with how our cars are geared, more boost at the upper rpm range would help to mitigate some of that loss, but yes the engine will never pull nearly as strong to redline as a gasoline engine. |
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#95
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Found this box too, which provides more adjustability. It looks to operate in a similar manner as the DTUK which seems to support many different diesel platforms.
http://www.chipmydiesel.com/shop/bmw...upe-p-196.html |
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#96
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In keeping with the discussion I thought this is was a good summary taken from myturbodiesel.
Common turbo myths dispelled The biggest myth is that every turbo car can make more power just by turning up the boost. Boost is only a measure of intake pressure. Pressure can only be created when there is resistance from a restriction. Everything else being equal and within reasonable limits for the setup, more boost makes more power only if the turbo is operating in an efficient range of performance and if the rest of the setup can benefit from it. Most turbocharged cars have a little room to safely increase boost. If you were to increase the boost to the point where the turbo is trying to move too much air, it actually reduces performance. This is because past the point of diminishing returns, a turbo is basically blowing hot air. This hot air creates intake air pressure and more boost because boost = measure of pressure. Again, back to the idea of volumetric efficiency, you want the maximum mass of air for the engine. Unless the air can be cooled sufficiently by the intercooler, the density of the air might actually be less than it would have been at a lower boost level. This psi level of diminishing returns is different for every setup and every car and even varies by ambient conditions. At that point, some modern cars compensate by using their computer and sensors to adjust the timing to prevent detonation. The TDI engine car computer has air temperature and pressure sensors and a program that will prevent increased power if the only change is increased boost. You need a chip or other performance enhancement to increase fueling, see 1000q: basic performance upgrades for the TDI for more details. Again, it is a common mistake to equate boost, or intake pressure, with denser air. Assuming the other variables are constant, the ideal gas law PV=NrT shows that if you raise pressure, temperature increases. Also keep in mind the above paragraph about operating a turbo outside of its areas of efficiency. It's easy to get so caught up with quick power gains from more boost pressure that one can forget that the ultimate goal of turbocharging is increasing air density, not just pressure. In designing the engine as a whole system, you want to create the same amount of power with the least amount of boost, within a range, to reduce stresses on the engine and turbo and to keep air moving at a reasonable speed throughout the intake tract. One more time: boost pressure is a measure of intake restriction. You could put a choke in the intake air path and that would also create boost (but reduce power). A turbo moving a lot of air but showing relatively low boost on a boost gauge means there is low air restriction in the intake air path. Remember, the goal in increasing power is to move more air, more efficiently, not just create boost. Changing camshafts to allow more air into the combustion cylinders, changing the combustion cylinders by boring and making the diameter of the cylinders wider, or stroking the engine and making the length of the piston travel longer, can all increase the amount of air moved. Adding a larger turbo does not mean the engine will make more power. In a modern car, the turbo is regulated by sensors, computer feedback, and solenoids set to control the boost at a certain pressure. The computer measures the pressure with sensors normally at the intake manifold or some spot right before the intake manifold. Everything else being equal (load, rpm, etc), one large turbo and one small turbo will flow identical pressures of air at a given psi but remember that psi is just a measure of pressure - air mass is what matters and is what makes power! Here is an example: to flow a certain amount of air, where a smaller turbo may have already passed its maximum efficiency and is blowing mostly hot expanded air, a larger turbo will still be operating in its area of maximum efficiency and is moving cooler denser air at the same psi. Again, assuming that one turbo is stressed too much and the other is in its peak efficiency, they are both giving the same psi but not the same density of air. 20 psi is always 20 psi, the difference between an efficient turbo and a turbo blowing hot air is the temperature of the air coming out of the turbo which affects density. 20psi of 50oC air is not the same as 20psi of 14oC air. There are also other factors that effect this such as the size of the turbo housings, backpressure, etc.. You want to select a turbo which balances responsiveness with moving your desired mass of air. Do a lot more research and consult your performance and parts vendor before crunching the numbers and selecting a turbo setup. The same turbo on a 4.0L engine will respond totally different than on a 2.0L engine. |
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#97
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__________________
--Aaron |
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#98
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While digging for a good animation of how the turbos are fed I found this which has some good info on the M57 in it as well.
http://www.scribd.com/doc/56011951/BMW-Common-Rail |
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#99
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#100
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Looking past that page in that document it looks like the small turbo is on standby for most of the rpm range and the big one does the bulk of the power making.
__________________
--Aaron |
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