09-02-2012,02:04 AM

Originally Posted by
Jake
What do you think you're looking at france320isco? That graph just shows three runs of the same engine. It is not to compare different engines or modifications.
If you want to argue this, then lets start with the correct graph.
The fact is, the modified engine is faster. Period.
Jake
Don't be disappointed, i'm not selling anything, nor i want to "argue" it is just a techinal "basic" consideration.
I knew (i understood from your message) that those were three tests on the same engine, maybe i didn't make myself clear.
In point of fact i compared them to stock as you can see.
On this other graph we have a torque increase from 200.16 to 214.65 (if i got it right) which is the 7.2% (stock 210Nm - all the more useless with respect to it 2.2%).
So, again, the tuning was useless and, as far as i can see, the % gain is so low that it is probably inside the dyno bench error which is not indicated (each measure "on earth" is error-affected) we have just a "correction factor" but no indication of the range on the measure and about what is being corrected: 1% - 2% - ...4%? On what? Torque? Speed? Power? All of 'em?
Now if the error was in the same direction and of the same value in both tests, well, one can reset it by making the difference between the results, but it never does, so an indication of the "standard" accuracy vs power and/or torque (maybe given by the bench maker) is always to be provided.
From the three tests above 213/210 = 1,4% is ~ the maximum bias, but it doesn't say anything about the error (it maybe only say that statistically it is always in the same direction which could make the +7,2% a "true" result).
Well it is not so easy to have two identical test, one should need a climatic chamber.
Surely the engine is faster (in wot condition, nothing can be said about the pt behaviour) and the outputted hp is greater, no doubt about it, the maximum torque is outputted @6751rpm, as i stated above (4900 - 5000 stock) this is probably related to the cams work and i still hope that this car is not driven @ that speed 24h a day
.
But it is not outputting more torque, it is just available at higher rpms.
One could see the effects on torque by making some mixture adjusting in the 6000 / 7000 wot map: if all the work has given "more air" in that range one should see more torque (at least a +10%!!! vs stock or vs intial condition).
Now, to make a comparison, 30Nm is the torque outputted by the human leg on the bycicle pedal, just to understand the order of magnitude.
And about the second picture: valleys, mountains...A smoothing via some noise filtering (also via an error estimation) would be welcomed! 
All this is just to say that an engine IS torque, nothing more, nothing less.
The motorsport engineers set it in the 4000/5000 range, for driveability purposes maybe, i don't know.
Here we have to wait >6700 rpms (7240 -> rev limiter). Maybe something related to the "i want it higher" which is personal choiches, nothing to argue about it.
The alpha n CEO have a plot of a 320is with only alpha-n installed that reports a +20Nm gain. Even if it is not a "marketing" dyno test you can find online similar results with just eprom chipping.
I told about the "marketing dyno" cause there are evidences (at least on a lot of forums) that the an system ONLY (forget the gruppe A motors) is not a great deal for engine gains.
And, if it is not tuned properly, it is a plain disaster, simply because the stock engine was designed for ITS OWN INTAKE PATH.
But again, this is obvious, given some easy physical principles (the bottle
).
Last edited by france320isco; 09-02-2012 at 02:30 AM.
power is nothing without drift