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The Basics of Tuning and Timing
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02-24-2011, 07:50 PM | #89 | ||
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For the vanos, you can see the timing adjustment in the tables ramping up and then down from 3500 to 4500 due to the different cam durations. I guess what i was asking was more if there's a direct relationship, so if a hand full of boxes are determined on the dyno or by ear, you can fill in the rest. Quote:
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02-24-2011, 08:01 PM | #90 |
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Correct me if I'm wrong, but using a higher octane might be a different reaction than using a lower octane. I would think that it would be harder to adapt when the ECU is bouncing off the maximum timing tables. Or do you mean that it was tested where the ECU sensed knock on high octane and bumped itself down and then didn't try to keep the new lower timing at all? It just tries to advance timing a set amount in a set period of time no matter what and relies on knock events to go back down 3 degrees? Implying there are no "octane adaptations"?
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02-24-2011, 08:09 PM | #91 |
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No what he means is that when you use race gas, the stock tune does not knock becase the car is able to reah the set maximum timing values without any knock detection events.
There is no "bouncing" off the maximum timing points, that's why they are called maximum. (as I understand it) |
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02-24-2011, 08:11 PM | #92 | |
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This is not a hard concept to understand guys. Set timing below knock, car won't knock. Very simply and works just like any other car. |
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02-24-2011, 08:13 PM | #93 | |
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02-24-2011, 08:16 PM | #94 |
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Mike PM'd me earlier and we are attempting civilized discussions but he avoids my questions when I answer all of his. My latest was what would he set the timing at if he had a full standalone on this car and could tune it anyway he wanted. I asked fro timing from 4000-7000 because I know the answer. I just couldn't think of a way around answering it honestly. And I think I was right - hence no answer
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02-24-2011, 08:16 PM | #95 | |
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The point of the race gas test is to prove that the car CAN run knock free IF the maximum timing values are set properly, (ie low enough) to prevent the knock sensor from detecting events an thus having to drop timing. With increased load, timing table maximums need to be dropped relative to stock values in order to prevent timig drops based on knock sensor detection events. |
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02-24-2011, 08:20 PM | #96 | |
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The reason why a person sets an ignition timing table is so that under different load & RPM conditions, the ECU knows how to compensate accordingly. On most other cars, you also have short and long term fuel trims (STFT & LTFT), that adjust accordingly based on your conditions, and alter fuel trims accordingly (mostly CL, but OL to a smaller extent long term). They also have IAM settings, which modify timing at load sites based on historic knock and adjust slowly over time (just like autotuning, but only for timing). As far as timing and AFR's go, all cars are different. Boxers don't dissipate heat as well, and as such are more prone to detonation than inline motors. Because of this, Subie's are traditionally run a little richer than other turbo 4's (typically around the 11.5:1 mark, many times tapering into the low 11's/high 10's), in order to use the extra fuel to cool the heads/lower cylinder temps in order to stave off detonation. In contrast, I've seen 4G63 powered EVO's that were pretty happy around the 12.5:1 mark, and 2.3 DISI motors (also DI) that were happy anywhere from 12.5 to 11.5 depending on mods and tune. Although it's NA, my brother's GTO runs well around the 13-13.5:1 mark under full load without an issue. My point? All cars have different preferences when it comes to AFR and timing. This is to be expected. I'm actually pretty excited about seeing what I can make this engine do, but at the same time, it is still an internal combustion engine, and as such falls under the same principles that other internal combustion gasoline engines fall under. I've played with meth, race gas, and E85 (love the corn juice!!) over the years, all of which require some form of tuning in order to reap their full benefits... but across the board, the principles stay the same. Every car is going to be slightly different, which is why I believe custom tuning is so important, but ultimately, they'll all gasoline internal combustion engines, many of which have the same parameters. Honestly, I know you're trying to sell a product, and I respect that, I know it's a tough job, but I think you might benefit from an EFI 101 course. I think by seeing multiple platforms, and the differences between them, you might also realize just how similar the guiding principles are regardless of the variations between motors. Again, I'm not trying to come off as a prick, but I think you could learn a good bit, and expand your overall knowledge base, which would help with sales IMO. I also think you should learn to accept the fact that timing control can be beneficial when it comes to optimizing (<--key word) a tune. It's not personal, and it's nothing against the JB3/4, so please don't take it as such, but just realize the truth of the thing. In all reality, the Procede doesn't have nearly the user adjustability as many standalone ECU's (Haltech, Motronic ect)... look at the price difference... it's not supposed to. Many people don't want/need that level of involvement. Comparatively, the JB4 is less than optimum due to the fact that it doesn't control timing... it's also only $479. You get what you pay for, and people understand that. It's been proven (even stated in my original post) that on otherwise stock cars, the DME is adaptable enough to save your motor running a JB3/4, that is well understood, and agreed upon. However, it is not optimal, as optimal IMO would be a map created specifically for a person's car, with their specific mods, on their fuel, in their environment, that does not see knock under normal conditions (i.e. consistent). Bang for buck, you can't beat the JB3/4. This is a well known fact. However, arguing that an inferior product is somehow on the same level as it's more capable competition is a fallacy. It's cheaper... you own a good portion of the market due to price point... for the life of me I don't understand why you would argue with so many reputable tuners & knowledgeable enthusiasts who have tuned countless vehicles, when it does nothing to sway your potential customers. Again, I am not trying to flame you, as a matter of fact, I don't think you're a bad guy, and I'm sure you're just trying to stand up for your customer base, but honestly, it's not necessary. It is what it is. The JB doesn't control timing, which is a crucial factor when tuning for optimum performance, consistency and safety. Period. It's not a bad device, it offers great bang for buck value to those who don't care (large majority), and doesn't pop motors on this vehicle. That should be enough. Either that, or if you don't like the negative stigma around having no timing control, simple answer- build a better machine. Isn't the Proboard going to have timing control? Viola. Either way, again, not trying to be a prick. I wish you the best of luck in your endeavors, but for those of us who have tuned many different platforms, the core principles of tuning are still the same. Just me $.02 -Brandon
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02-24-2011, 08:28 PM | #97 | |
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02-24-2011, 08:35 PM | #98 | |
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I was only pointing out to Mike variance between gears and one of the prime reasons why gear selection is crucial when dyno tuning (for a turbo car). On an NA car, I'm going to choose a gear with a higher load for the exact reasons you listed. I'm a big fan of tuning under harsh conditions.
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02-24-2011, 08:44 PM | #99 | |
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02-24-2011, 08:53 PM | #100 | |
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02-24-2011, 08:57 PM | #101 |
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02-24-2011, 09:11 PM | #102 | |
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Reminds me of way back when Terry constantly asked questions of Shiv trying to learn how build a cheap resistor tune.
Times have not changed. I'm always wary of who is actually the one typing what comes through Mike's account Quote:
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02-24-2011, 11:07 PM | #103 | |
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If combustion is stable, there would be no abnormal noise for the sensors to pick up - -the noise would be normal combustion noise by definition. It is very unlikely there is a harmless, partially degenerated wavefront, that happens to create audible vibration, without any potential for harm.
I do believe that knock varies in intensity and severity, influenced by how far off the timing was, the load, temperatures, cylinder pressures, at which it occurs, etc. The less accurate the tune is at getting timing right, in light of all the factors, the more potential for knock events, in both severity and number. Catastrophic loss may be rare, but heightened wear and tear is almost certain. I come from other engineering areas, and have no tuning background, but this seems obvious to me. Yes, I inferred it from what I've read here, but also did my own thinking and reading... Quote:
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02-25-2011, 12:27 AM | #104 | |
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02-25-2011, 06:32 AM | #105 | |
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platform. Timing is managed on a cylinder by cylinder basis and is almost perfectly timed in every situation, condition, and octane. It's never lazy or undertimed and never knocks. Try doing that with manual timing tables. Also this has nothing to do with products. The fact is there are more tunes out there using the JB3s method of timing control than there are using CPS. It's about understanding how the DME and tunes work. I think clap135 put it really eloquently when he said if you add race gas and timing goes up its knocking. That seems a reasonable position and as I've said that will happen with any tune on this market. If you don't believe it then let's put that to the test once again. You'll be surprised. Mike |
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02-25-2011, 07:44 AM | #106 | |
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02-25-2011, 07:49 AM | #107 | |
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But...those same BMW engineer saw fit to reduce the timing tables in the IS version of the engine. Why would they do that if the system that they created was so good at adaptation that it shouldn't have been needed based on your reasoning? They increased boost in the IS and reduced the maximum timing allowed under certain load conditions. We are increasing boost even more with the aftermarket tunes, yet you suggest that we don't need to adjust the timing tables? I would think it would be prudent to follow BMW engineerings lead since they know the abilities of this engine and DME better than anyone. |
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02-25-2011, 07:59 AM | #108 | |
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You describe the JB4 as having great results because of a safety system the dme has. It is great at pulling timing based on a number of characteristics and feedback (short and historic). You say that because it is so adaptive it is so great. Yes for a factory stock setup its great! When people tune a car they tune it to gain power, consistancy and reliable. The entire strategy of tuning a DAILY DRIVER is to tune the car to a safe distance from knock thresholds. Are you getting every whp out of the car? No - but that is the point of a daily driver tune. The goal is to extract a good amount of power and leave a margin of safety so the car is okay (no excess wear -not only focusing on blowing a motor) in even the harshest conditions. Using the dme's ability to pull timing is a fantastic BACKUP. HOWEVER lowering the set points so that 99% of the time that logic in the dme isn't used is even better. The scary thing here is that you know a little about how the dme works but you know nothing (or are purposely going with this absurd approach you seem to take) about why and how to use the logic in the dme. I can only imagine how fun it would be to put you through a lie detector and ask you questions lol. You can say that the comments here hold true on other platforms but not here - but you are unfortunately very wrong. The theory behind mapping timing doesn't change from platform to platform. Timing tables are what change - the actual values. Subaru, mazda, mitsubishi etc. all run off the same physics and tuning theory. An adaptive ecu doesn't change the game - it just presents new features. An example of this...lets say openecu was available for this platform so we leave all vendors/tunes out of this. If I make my timing tables with maximum timing values of 5* by redline so I never knock because it is that conservative - and I go put race gas - guess what - my timing isn't going to get higher. Thats why you make race gas maps. So that when you run race gas you can run more timing. That is how you tune. An adaptive ecu doesnt change tuning theory at all. |
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02-25-2011, 08:53 AM | #109 | |
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02-25-2011, 09:10 AM | #110 |
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