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02-13-2013, 06:55 AM | #46 |
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I'm looking over this and thinking about getting a set of used mufflers to try, just for fun.
Very curious how this all pans out. I like the simplicity of exdos's mods, since you not really reconfiguring anything just cutting stuff out then rewelding the muffler back together... I also wonder what would happen if you just cut the pipes at the very front section, closest to the inlet.. You'd basically be creating a "chamber", and leave everything else intact. The results would probably not be that much different than stock?
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02-13-2013, 08:01 AM | #47 |
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I want to remove the slight drone at 1.7k - 2k rpm that I reported with my exhaust mod, so I've reopened them and fitted some perforated stainless sheet as shown in the photo below, which I hope will cure this problem. I've not tried them yet but I've tried to reduce the area of parallel surfaces opposite each other.
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02-13-2013, 12:08 PM | #48 |
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Correct me if I'm wrong, but if having parallel surfaces increases drone, why did you put the two pieces that you added parallel to each other?
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02-13-2013, 12:20 PM | #49 | |
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I will just fit one of these modded silencers with the other remaining OEM, and if that's OK, I'll fit the other modded silencer. If it doesn't work, I'll try something else. |
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02-13-2013, 12:27 PM | #50 |
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Very interesting, keep us posted. I'm highly considering doing this mod the more I think about it, so I'm very interested in the results.
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02-16-2013, 07:25 PM | #51 |
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Isn't that the same DashDyno from which you claim your Z4MC has 370 RWHP with no mods but a home-made scoop? I've been entertained reading your thread on the euro forum where your outlandish claims aren't being met with any resistance.
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02-16-2013, 09:04 PM | #52 |
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02-17-2013, 05:03 AM | #53 | |
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The DashDyno is a datalogger (see: http://www.auterraweb.com/) which connects to the OBDII socket and it records any of the PIDs (Parameter Identities) which the vehicle's ECU will make available for the datalogger to read. Different vehicles yield a different selection of PIDs to dataloggers, and the Z4MC actually yields more PIDs than the Z3MC. It doesn't matter whether you connect a standalone datalogger such as the DashDyno, or any other datalogging device, such as the Dash Hawk or DashDaq, or a PC based datalogging application such as ScanGauge, or app for iPhone or Android; the information available for recording through the OBDII socket for each car will always be the same. These devices and apps are not toys: they are hi-tech solutions which I'm sure automotive engineers would have given their right arms to have had available to them in earlier times during the development of vehicles. The information which the car's ECU will yield to any datalogger is exactly the same data that the ECU uses to operate the vehicle. Many of the datalogging devices and apps have the facility to compute dyno runs, as does the the DashDyno and I've used exactly the same car profile and protocol for all my dyno runs with my Z4MC. Nobody challenges the baseline recorded figures of the car in OEM condition, (which gives close to OEM spec figures) but the likes of you find it difficult to believe that it is possible to modify the OEM air-intake in such a way that it can utilise the ram-effect even better. I've got news for you, the Z4M's intake system is very good but it's not perfect. I've spent a lot of time examining and recording data with the OEM intake and with various mods so that I can understand how it can be improved using scientific principles which have been known for very many years. From my appliance of known science I have been able to increase the peak torque of my Z4MC by 7% and because the torque curve also tends to plateau rather than fall away, this translates into a considerably greater horsepower figure than you'd normally expect to see - it's basic maths. The raw data produced by the Z4MC's ECU for airflow through the MAF at WOT shows that with my various mods I'm presently able to increase the peak airflow at 7900rpm from OEM by 8.8%. Since the ECU adjusts the fuelling to match the airflow through the MAF then an 8.8% increase in air ingestion with each cylinder fill with an increase in fuel to match must produce an increase in torque. Since horsepower is a measure of work done in unit time, then it's obvious that an increase in torque, which can be maintained through the rev range (helped considerably by the VANOS), will considerably increase the horsepower. There's a lot more to it than your dismissive "home-made scoop". My surprise is not with the figures, but at the fact that nobody else has done this before. If you want to continue with this please make your posting on the other forum. Last edited by exdos; 02-17-2013 at 06:34 AM.. Reason: more info |
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02-17-2013, 10:25 AM | #54 |
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Oh I'm a believer in aftermarket intakes, as my sig would suggest. However, they are predominately for increased sound and throttle response and perhaps a minuscule increase in power (greater airflow etc etc) but that claim hasn't really been proven either way.
But just so I'm clear, your saying your intake ALONE will net you an additional 20ft lbs of TQ over stock? |
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02-17-2013, 10:46 AM | #55 |
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If you're so confident with your car throw it on a roller dyno and lets see the numbers off of a dyno spreadsheet.
A graph from an excel document is as worthless as me twirling my fingers in the air. It holds absolutely ZERO value. Basically with your paragraph summed up. Putting a 8" intake will yield more airflow (with my many many many years in science) making the ECU MUST match it...lol I'd be interested to see the AFR if these figures are actually correct. I put my money that you're running on the lean side. |
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02-18-2013, 04:56 AM | #56 | |
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Yes, in that ballpark. I did some more datalogging yesterday and I posted the results on the thread on this topic on the other Z4 forum. The datalogging confirmed my earlier results. I know these results are impressive, and I understand scepticism, but I'm doing something which is quite different to the typical aftermarket ram-air intakes and CAIs. |
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02-18-2013, 05:04 AM | #57 | ||
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Watch the video of a few dynoruns at this link: http://www.tecnocraft.com/Tecnocraft...ystem-P18.aspx Why does heat-soak occur on the dyno during multiple runs, which causes the dyno results to be different for each run? Which of those figures is a representative of the car in "real world" driving conditions? Datalogging shows that heat-soak does not occur in real world conditions of acceleration, in fact the opposite occurs: IATs fall during acceleration. The data in those Excel graphs is exactly the same data produced by the DashDyno, but exported as a .csv file. This way, I can merge the data from multiple files so that I can view data in "comparison graphs". This might be worthless to you, but it's priceless to me in developing my intake. Quote:
You've just lost your money. Take a look at the graph that I've posted in the other thread on the Z4 forum: it shows that in 3rd gear acceleration at WOT, the AFR is 13:1, that's not lean, is it? My datalogging of AFRs shows that when the throttle is open to a lesser degree the AFR is around 14.7:1. These figures are the same as when the car is in OEM state. EFI operated by an ECU does not behave in the same way as curburettors and ram intakes. Clearly, the ECU is capable of matching the increased airflow without any need for remapping, in the same way that it would be capable of proper fuelling under extreme cold conditions and high ambient pressures as occur in the Arctic Circle. Last edited by exdos; 02-18-2013 at 08:53 AM.. Reason: more info |
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02-18-2013, 06:17 AM | #58 |
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Here's what I don't understand. I don't understand how that device can simply use speed and RPM to determine torque. As we all know, torque = force x distance (lb-ft or N-m). HP is simply torque at a given RPM.
Using one of these scanner tools, you can measure all of those things except a force. The only way this scan tool can calculate that is by essentially back-solving using the A/F ratio, airflow, and air intake temps. My guess is that scan tool isn't setup specificially for any given engine, so assumptions have to be made on volumetric efficiency, thermal efficicency and mechanical efficiency. The one thing that this CANNOT account for is friction inside the engine, which can be significant. That said, I don't really think dyno numbers really mean a whole lot, as a number itself. They are only useful to compare setups. In other words, you do a baseline run of a car in it's stock form, then install your modifications, then re-run the car ideally on the same dyno at similar ambient conditions. I don't care if the dyno says you make 30RWHP or 3000 RWHP, if you show a 30HP gain, it's still 30HP regardless. That is where I think dyno's are most effective in showing the CHANGE. Remember you can see EASILY see a 10HP swing just by changes in ambient temperature.. It's two fold because by decreasing the ambient temperature you increase the density of air, which in turn makes the engine injest more air, and by increasing the temperature DIFFERENTIAL of a heat engine, you increase the overall power output and to some extent the thermal efficiency of the cycle.
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02-18-2013, 08:23 AM | #59 | |
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vehicle weight, Cd, frontal area, gear ratio (i.e. gearbox ratio x diff ratio), tire diameter, ambient temperature, ambient atmospheric pressure and geographic elevation above sea level. Since the actual method of calculation is not published I'm guessing that the method used by the DashDyno (and other dataloggers) uses engine rpm and calculates distance based on the tire diameter as a unit of length multiplied by engine rpm x gear ratio. Since Force = Mass x Acceleration, this can be computed from the data logged and used in conjunction with the constants in the vehicle profile so that the torque equation can be solved. The environmental figures are used as corrections to the data so that the results are "standardised' so that all results are comparable. Like you say, I agree that dyno figures don't actually mean a lot. What matters to me is that the DashDyno produces repeatable and reliable figures for any specific vehicle so that I can compare the differences that might occur when modding of the intake and exhaust system. A gain or a loss is a gain or a loss on any scale, and if the DashDyno shows a significant gain, then I believe it is a genuine gain. In any event, I don't particularly rely on the dyno features of the DashDyno, I prefer to use the actual raw data logged from recording various specific PIDs, which also show significant beneficial changes from successful modding, such as airflow through the MAF and the difference between IATs and ambient temperature. Last edited by exdos; 02-18-2013 at 08:56 AM.. |
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02-18-2013, 08:58 AM | #60 |
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At the end of the day, none of these other guys have to drive your car, YOU do. If you're happy with the results, regardless of what they are, then it's a worthwhile excercise. Props for trying something new!
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02-18-2013, 09:43 AM | #61 | |
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02-18-2013, 10:25 AM | #62 | ||
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Just sayin Especially with Cd, weight, and instant tire diameter...those values WILL be off. Last edited by Kgolf31; 02-18-2013 at 10:31 AM.. |
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02-18-2013, 12:47 PM | #63 | |
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You've been reading the thread on the other Z4 forum, and in it I've described how I've been through the same scenario when I did the same sort of mods on my Z3MC and people like you doubted that I could produce significant gains with relatively simple mods to OEM parts. Consequently, I took that car onto two different static dynos at well-respected establishments, including that of Evolve (you've heard of them on this forum) and proved 1. that my mods produced significant gains for FREE and 2. that my DashDyno produces comparable figures to those produced by static dynos. All my mods and details of the dyno runs (including a video of my car on the rollers) is well documented and available on the internet if you care to do a search. I'm not going to rush on to static dynos at anyone's request. All my figures and graphs are exactly as exported in .csv format from the DashDyno with no manipulation. I do understand scepticism, and the amount of proof that you require to convince you is entirely down to your own choice. All I can tell is I know what I have done to achieve such gains and that I have followed well-known scientific principles to achieve them. Last edited by exdos; 02-18-2013 at 01:04 PM.. Reason: more info |
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02-18-2013, 12:53 PM | #64 |
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What you're saying is that I'm fabricating the data? If you think that then nothing I can say/do would convince you otherwise. I can assure you though, that anything that I publish is exactly as yielded by the ECU to the DashDyno. You are seeing exactly the same information that I see. It's your choice whether you believe me and the figures or not.
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02-18-2013, 02:06 PM | #65 | |
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I wasn't able to find anyone verifying the numbers of a dashdyno against a dyno to check for validity. But your numbers are not possible. Let me explain: A standard car, with 330hp factory, usually dynos at around 280rwhp. Dividing those we get about a 17% drivetrain loss. Based on this we can assume that the 15% drive train loss people usually use as a rule of thumb is reasonably accurate. Based on that, if you had 370hp crank, it would mean that you would have around 310 to 315 wheel horsepower. There's two e46 N/A builds both have an evolve air box, alpha-n tuning, one has supersprint headers / x-pipe, the other euro headers / cats. Both of them dynoed at around 320 wheel horsepower. There's no way you're within 5-10hp of that with just a scoop and gutted mufflers.
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02-18-2013, 02:22 PM | #66 | ||
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I'm not the designer or author of the software of the DashDyno, only the end user. I have no reason to consider the input parameters for the vehicle profile to be wrong. Quote:
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