A few posting ago, you said you wanted to get this thread “back on track”, but it seems that you just want to keep coming back for more!
fighting_fish said:
On the first post you state that the car made 321.6, then after your intake mad 323.3... Not exactly a huge increase. We also don't have a baseline for your car, so even though your car dynoed very well, we don't know how much is due to your intake or exhaust.
As I've always stated, the full benefits of the ram effect
cannot be replicated on a static dyno unless there is also a speed-related fan which replicates the increase in ram pressure with increase in speed, and since you say you are an engineer, I am surprised that you do not seem to recognise this fact. The dyno results which you have quoted from my posting to which I referred, were recorded on a static dyno with a fan of fixed speed and you dismiss the benefit of my mods by saying that the horsepower gains are not great, but you have completely failed to mention and acknowledge the very significant gains in torque which simultaneously occurred during the dyno runs in completely unfavourable conditions. Why don't you want to recognise that? That S50 Z3MC was another owner's car and it was independently tested and I had no influence over the recording on the dyno. In OEM format that car made 336.8Nm (248.4 ft/lbs) of Torque and after I'd slightly modified the air intake and silencers on that car, it made 355.2Nm (267 ft/lbs) of Torque:
that's a very significant increase of 5.46%!
In an earlier posting you wrote: "
The point is the dyno is more than accurate enough. Your discounting of dyno entirely is what I disagree with, it's provably more accurate than the method you're using". But it seems that now I've presented some evidence of my well-documented mods using your favoured dyno method, you're now wanting to gloss over the fact that a few relatively simple mods can produce provable and significant gains in torque as shown by the
dyno method you recommend and prefer! You are just being perverse now that I've proven my point!
As an engineer, ask yourself why did the torque increase significantly yet the horsepower didn't increase by very much? It's obvious that the recorded increase in torque after modding the air-intake and silencers must have occurred because the intake and exhausts systems were made less restrictive, allowing the engine to breathe better, thus increasing the Volumetric Efficiency, and thus allowing the ECU to increase the fuelling to increase torque and power. Further, since peak torque occurs in the middle of the rev range, and since the effective wheel speed in the middle of the rev range on the dyno whilst in 3rd gear is around 75mph, which was equivalent to ram pressure created by a fan in front of the car operating at a wind-speed equivalent of around 75mph, the increase in torque has been recorded. However, as the car continues to increase engine speed on the dyno above the maximum capability of the fan, the engine begins to suffer from
relative air starvation, which will produce a lower torque figure at higher rpms than will occur in real world conditions. Therefore according to the formula from which horsepower is calculated:
HP = Torque x RPM ÷ 5252 the maximum horsepower, which occurs at engine revs above that which produce maximum torque, will be less than would occur in real world conditions. As such the figures produced by from a car with an air intake designed to harness the ram effect will be unrepresentative of what
really happens on the road and therefore are intrinsically inaccurate and unreliable. Any one who doesn't understand this point just does not understand the phenomenon of the ram effect and the potential that it offers for increased engine performance.
It must be noted that the mods done to that car in question have since been developed further on my S54 Z3MC and Z4MC and consequently I have been able to obtain gains in torque which are greater than 5.46% as already independently proven on a static dyno in unfavourable conditions. And, because, in real world conditions, I have been able to harness the ram effect, the torque curve doesn't fall away in higher rpms, as occurs on the static dyno, therefore, the horsepower recorded with the DashDyno shows a much greater percentage increase entirely due to the formula used to calculate HP. This is entirely due to mathematics and if you properly understood this and the potential that ram-effect has to offer, you would see how such excellent figures have been achieved. I will explain this further below.
fighting_fish said:
You DONT know that your data is accurate. Dash Dyno is using ONE and only ONE figure to calculate all its numbers: the output of the MAF (sure it's using the weight of the car and all that, but the one measured variable is output of MAF). I've already explained in detail why that number can be wrong, but you either refuse to understand or refuse to see reason.
That number MAY be right, but you need to verify it with some other measurement. Until then it's speculation, not engineering.
I really can't tell if you think that my DashDyno is an unreliable data-logging device or whether it's the accuracy of the car's MAF that you are so against? Or is it both? Yes, I can understand that the MAF may not be validated, but I've already previously tested this by swapping my Z4MC's MAF with the MAF from my Z3MC and also with a spare MAF that I have from an E46 M3 (all the same part number) and then datalogging my Z4MC with those 3 different MAFs, and I still get the SAME results. Likewise, I've been able to datalog different MAFs on my Z3MC, which also confirm that the different MAFs all produce the same results on that car too.
When the DashDyno is in "Dyno mode", the raw data that it records is the time stamp (in thousandths of a second) of the engine at every 100rpm intervals during acceleration in the dyno run. From this data, it is simple to calculate the time that it takes for the engine to accelerate from, say, 2000rpm to 8000rpm. Therefore, it is easy for me to compare the engine acceleration rate of a car in OEM state and when modded, which shows the real world gains, if any, of various mods. I have all this data for my Z4MC from OEM and all different states of modding. Just because I haven't yet presented this data for you doesn't mean that I haven't got this. Likewise, the DashDyno is able to log the vehicle speed and RPM (and all the PIDS available) on a timeline, so when I compare the results that I get today with those when the car was in OEM state, I can also see similar gains this way too.
Since the DashDyno is a sophisticated micro-chip device, are you in any way suggesting that the timestamps on all data could be inaccurate, or is it just the true calibration of the MAF that concerns you? If 3 different MAFs produce the same results with the same DME and DashDyno, are you suggesting that they are all wrong or would you accept that the results are in fact validated?
fighting_fish said:
Maybe you should leave the ad hominem at home. I am an engineer, I'm known for coming up with creative yet simple solutions to problems. I do a lot of R&D and experimentation, and sometimes the best ideas come from following your intuition. I will also sometimes try completely new things (either based on instinct, or based on theory) to see if things can be improved. I'm actually known for thinking outside the box.
The difference between you and me, is that I have experience on my side and because of that I measure things. And when I measure them, I measure them 2 or 3 different ways. I had a rookie engineer that misled by a bad measurement spent weeks down a bad path. We only found out when we put the tool into more rigorous testing and realized that it wasn't performing as it should, when we went back to the methodology we found out the engineer was relying on one measurement and his methodology was flawed.
So you are attempting to claim the high ground purely from your credentials! Despite all your claimed experience, it appears to me that you were incompetent and vicariously responsible in not properly checking and supervising the progress of the rookie engineer under your supervision throughout by allowing him to venture down a wrong path, and from what you've said, you could have prevented this from happening.
fighting_fish said:
Your problem is you refuse to do science and engineering. You're doing experimenting but failing to verify your results, therefore no meaningful conclusions can come from your experiments.
Engineering: hypothesis -> predictions -> testing -> evaluation -> new hypothesis -> predictions... rinse and repeat.
And ALL you have to do is either verify with a stopwatch, or race against another member, or SOMETHING. But you just want to blindly follow your dash dyno.
You are making so many wrong assumptions about my methodology when you haven't got a first clue about what I've done! As I've pointed out above, the DashDyno time stamps the data on a scale of 0.001seconds, so I've already got the data using a "stopwatch"!
You have previously stated:
"Also you guys keep focusing on HP and that's the wrong number to look at. Let me explain why:
The formula for horsepower is
and you have also previously stated that my numbers are "
so extraordinary", yet the reason why they appear to you to be so extraordinary is because you've not seen and worked out what is staring you in the face! As I've shown at the top of this post, it is you, yourself, who has focused on HP and ignored
the gains in torque that I provably been able to achieve.
Let me spell it out for you. Using the same formula to which we've both referred to calculate HP we've both given, (as appearing twice above), if the peak hp occurred at the the same revs as peak power, then if peak torque is 100ft/lbs and if the peak torque occurs at exactly 5252rpms, then peak hp will be 100hp (i.e. 100ft/lbs x 5252rpm / 5252 = 100HP). If the peak torque of 100ft/lbs occurred at the the same revs as peak power, but this occurs below 5252rpms, then the hp will be less than 100hp (i.e. 100ft/lbs x 4900rpm / 5252 = 93.3HP) and likewise if the peak torque of 100ft/lbs occurred at the the same revs as peak power, but this occurs above 5252rpms, then the hp will be greater than 100hp (i.e. 100ft/lbs x 5500rpm / 5252 = 104.7 HP). Surely you agree with this?
Now if the peak torque can be increased by say, 5.46% (the same as was achieved with the S50 Z3MC tested and proven on the dyno as described above), so that the peak torque is now 105.46ft/lbs and due to using an improved air intake that harnesses the full potential of the ram effect, the torque curve now becomes a long plateau where peak torque now occurs at, say, 6700rpms, the hp can be calculated as 105.46 x 6700 / 5252 = 134.53hp. Therefore, if the OEM figures produced peak hp of 100hp at 5252rpms, then in this illustration, it shown that a 5.46% increase in peak torque which occurs at higher rpms can produce what I guess would appear to you as an extraordinary increase in hp of some 34.53%. As you know, horsepower, doesn't actually exist, it is merely a calculation to illustrate the rate of work as an "expression", and as this simple demonstration of the maths shows, the hp figure is highly dependent upon the torque curve.
Do you get it yet?