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форум - Normally Aspirated Powertrain - атмосферные двигатели, я лазил, читал, в общем там советы одинаковые - выпуск 2,25" максимум 2,5"+удаление катализатора.
впуск - там выложена статья по холодному впуску и выводы неодназначные кстати.
замена р-валов+прошивка то же есть статья.
увеличение мощности связанно с переходом на более высокие обороты отсечки.
вот статья-переводитьь не стал в общем все просто написано -
Ok, I've been looking into some intake setup options. One main one is a simple cone filter on the throttle body (MAP based car). However, I wanted to compare the stock box and if it did anything useful and if the stock intake plumbing had any useful effect. I ran a series of road dyno runs to compare.
For the comparison, I disconnected the battery and reset the ECU. Then I drove a short distance (few miles) to a test section of road. I proceeded to run 4 back to back pulls with the particular intake measuring some parameters like intake temp, air/fuel ratio, and so on. For each intake the ECU was reset and the same 4 runs were done. This is a direct comparison on equal grounds. Besides graphing out some data I also used Data Log Lab to plot torque and horse power. Everything was SAE corrected to current outside conditions with the exception of intake temps set at what the ECU measured for the intake. I figure this would give a less biased impression of each design's capability in the sense if I could pull the same temp for each.
The three designs tested were the cone filter on the throttle body, the stock box with no piping attached, and the stock box with stock piping attached. Cone filter to box shows the influence the box has and box to box with intake piping shows what tuning Subaru put into the intake tract or I should say at the very least what benefit a length of pipe has, tuned or not. I did not test with a length of pipe without all the resonator stuff. I simply don't have any laying around.
I'll note the pic is big at 1920x1080. I'll leave it as a link to keep this thread more readable. Simply click on in and view it in a different tab/window.
http://www.gigafiles.co.uk/files/185...asurements.jpg
The first set is the cone filter on throttle body. What should be noticeable in the TQ/HP graph is the low midrange dip in power. The data plots show that the intake temp is a bit lower then stock and that the air/fuel ratio is pretty messy. This seems to correlate towards the less then even resulting power band (not noticeable with heavy smoothing I'm using). This might be able to be tuned out or a small resonator could be added to compensate like the stock airbox.
The second is the torque box alone. Notable things are the improved upper midrange response in the TQ/HP graph but still lower low range power. The air/fuel ratio is ruler flat, and the intake temps are rather high. Note outside temp is 58F, so quite a jump. It's interesting that the cone is somehow better in this regard, partially specific to where the air is pulled from I guess.
The third is the full stock intake, piping, and all its resonator glory. Notable things would be the still high temps despite pulling from near the headlight (and maybe other places), the great low and midrange power, and again the flat air/fuel curve. There are definitely specific gains to be had by both the box and intake piping. You can also see that timing seems to be a little bit higher too with the stock intake parts.
That air/fuel spike at 5500 rpm, I have no clue what it's doing. It repeats on all setups and all runs. On an actual dyno, this never shows up with whatever they're using to measure air/fuel. I can't say what it is.
I will make a couple notes. First, this is run with an I-Speed SRS-10 flash. This was designed specific for the stock setup. It is possible that the cone filter on TB setup could be simply retuned to run a ruler flat air/fuel curve too. The stock intake manifold design does run a very small plenum volume. This would make the intake manifold and MAP more sensitive to the intake parts then normal. With a larger plenum volume, it's very well possible air/fuel numbers would be far more consistent. I resonator before the throttle body would probably cause the same benefits. The rest of the car consists of a full exhaust and intake and manifold spacers.
I would like to eventually grab some piping and test also a short ram intake with the cone filter and a cold air intake design both with the cone filter and with the stock box. If I'm compelled and can find an adequate part, I would like to run a helmholtz resonator inline in the intake piping of the cold air intake setup. I have a feeling that the stock box or the resonators in the stock piping may attribute to the improved low and midrange response through making use and reflecting back those resonances. These resonators act as spring boards for the pressure wave pulses, aiding in airflow. I'd be curious to see if there is something useful there beyond just simply a tuned pipe of some length.
One final note is the high end power band. It should be noted that all of the intake designs, even the aftermarket exhaust did very little with the top end power band of the car. This is all cam work here as was stated by williaty in his own thread. I'll note that the intake may show different gains when the engine is actually tuned for high rpm use.