+1

Dit is machtig ..............http://www.youtube.com/watch?v=Vd0pPzLdOd4

Ik ken een aantal mensen die erg onder de indruk zijn van EPS uitlaten, die de uitlaat naar wens voor geluid en prestatie voor je bouwen!

http://www.uitlaten.com/main.html

Hoe doen ze dat dan met de prestatie? Testen ze de gecreerde uitlaat op een vermogensbank?

Weet ik niet; ze vragen echter wel naar de lay out van de motor en het inlaattraject en kunnen ook de mate van tegendruk bepalen.

Tegendruk is "Bull...."

Al eerder eens geschreven (geplakt )

I. Introduction
One of the most misunderstood concepts in exhaust theory is backpressure. People love to talk about backpressure on message boards with no real understanding of what it is and what it's consequences are. I'm sure many of you have heard or read the phrase "Engines need backpressure" when discussing exhaust upgrades. That phrase is in fact completely inaccurate and a wholly misguided notion.

II. Some basic exhaust theory
Your exhaust system is designed to evacuate gases from the combustion chamber quickly and efficently. Exhaust gases are not produced in a smooth stream; exhaust gases originate in pulses. A 4 cylinder motor will have 4 distinct pulses per complete engine cycle, a 6 cylinder has 6 pules and so on. The more pulses that are produced, the more continuous the exhaust flow. Backpressure can be loosely defined as the resistance to positive flow - in this case, the resistance to positive flow of the exhaust stream.

III. Backpressure and velocity
Some people operate under the misguided notion that wider pipes are more effective at clearing the combustion chamber than narrower pipes. It's not hard to see how this misconception is appealing - wider pipes have the capability to flow more than narrower pipes. So if they have the ability to flow more, why isn't "wider is better" a good rule of thumb for exhaust upgrading? In a word - VELOCITY. I'm sure that all of you have at one time used a garden hose w/o a spray nozzle on it. If you let the water just run unrestricted out of the house it flows at a rather slow rate. However, if you take your finger and cover part of the opening, the water will flow out at a much much faster rate.

The astute exhaust designer knows that you must balance flow capacity with velocity. You want the exhaust gases to exit the chamber and speed along at the highest velocity possible - you want a FAST exhaust stream. If you have two exhaust pulses of equal volume, one in a 2" pipe and one in a 3" pipe, the pulse in the 2" pipe will be traveling considerably FASTER than the pulse in the 3" pipe. While it is true that the narrower the pipe, the higher the velocity of the exiting gases, you want make sure the pipe is wide enough so that there is as little backpressure as possible while maintaining suitable exhaust gas velocity. Backpressure in it's most extreme form can lead to reversion of the exhaust stream - that is to say the exhaust flows backwards, which is not good. The trick is to have a pipe that that is as narrow as possible while having as close to zero backpressure as possible at the RPM range you want your power band to be located at. Exhaust pipe diameters are best suited to a particular RPM range. A smaller pipe diameter will produce higher exhaust velocities at a lower RPM but create unacceptably high amounts of backpressure at high rpm. Thus if your powerband is located 2-3000 RPM you'd want a narrower pipe than if your powerband is located at 8-9000RPM.

Many engineers try to work around the RPM specific nature of pipe diameters by using setups that are capable of creating a similar effect as a change in pipe diameter on the fly. The most advanced is Ferrari's which consists of two exhaust paths after the header - at low RPM only one path is open to maintain exhaust velocity, but as RPM climbs and exhaust volume increases, the second path is opened to curb backpressure - since there is greater exhaust volume there is no loss in flow velocity. BMW and Nissan use a simpler and less effective method - there is a single exhaust path to the muffler; the muffler has two paths; one path is closed at low RPM but both are open at high RPM.

IV. So how did this myth come to be?
I often wonder how the myth "Engines need backpressure" came to be. Mostly I believe it is a misunderstanding of what is going on with the exhaust stream as pipe diameters change. For instance, someone with a civic decides he's going to uprade his exhaust with a 3" diameter piping. Once it's installed the owner notices that he seems to have lost a good bit of power throughout the powerband. He makes the connections in the following manner: "My wider exhaust eliminated all backpressure but I lost power, therefore the motor must need some backpressure in order to make power." What he did not realize is that he killed off all his flow velocity by using such a ridiculously wide pipe. It would have been possible for him to achieve close to zero backpressure with a much narrower pipe - in that way he would not have lost all his flow velocity.

V. So why is exhaust velocity so important?
The faster an exhaust pulse moves, the better it can scavenge out all of the spent gasses during valve overlap. The guiding principles of exhaust pulse scavenging are a bit beyond the scope of this doc but the general idea is a fast moving pulse creates a low pressure area behind it. This low pressure area acts as a vacuum and draws along the air behind it. A similar example would be a vehicle traveling at a high rate of speed on a dusty road. There is a low pressure area immediately behind the moving vehicle - dust particles get sucked into this low pressure area causing it to collect on the back of the vehicle. This effect is most noticeable on vans and hatchbacks which tend to create large trailing low pressure areas - giving rise to the numerous "wash me please" messages written in the thickly collected dust on the rear door(s).

@ASW: is de LMM dan in je cupfilter geknutseld, volgens Harley is het immers anders onvindbaar, of prefab door vorige eigenaar gekocht (en dus leverbaar)?

Volgens PCL is een Cupfilter met LMM aansluiting niet leverbaar - maar dat zegt natuurlijk niet 100% zeker dat ze er niet zijn. Gewoon Cupfilter kunnen ze wel leveren.
Aftermarket moet ik nog verder afstruinen. Wie weet vind ik ze alsnog.

Zou Manthey ze niet leveren? Ze worden namelijk geplaatst bij de motorupgradesetjes die ze aanbieden. Weet niet of dat met of zonder LMM is...

De luide versie van Europipe

http://www.youtube.com/watch?v=e_66kady ... re=related

met weer dat blubbergeluid wat ik op een GT3 waardeloos vind klinken

dat vind ik net mooi Zo zie je maar dat smaken verschillen

Ik weet dat het niet hoort...maar wat kost zo'n setje van Europipe?

2200 euri

Bruut!

€ 2.200,-- is voor Porschebegrippen nog wel acceptabel. was een sportuitlaat bij de 996 GT3 niet ook gewoon een fabrieksoptie?

Ik vind alleen het stationair geluid van mijn GT3 verschrikkelijk.... net een grasmaaier. Maar eenmaal boven de 3000-4000 toeren is het eigenlijk standaard al prima

Is deze niet gewoon te plaatsen

http://www.prestigebodykits.com/product ... p-228.html



in combinatie met deze

http://www.prestigebodykits.com/product ... p-332.html

Aanzuiggeluid is echt iets heel anders als uitlaatsound, wat de meesten zoeken denk ik

Ik verwacht dat je wel problemen krijgt met de geluidsnormen waaraan circuits zich moeten houden. Dus doe je een keer een circuit uitstapje, word je dan van de baan geplukt?

heb de volledige K410 kit van Manthey John... zat op de auto toen ik 'm kocht... vond het maar niks in het begin en heb hard rondgekeken naar iets anders. Europipe stond bovenaan de lijst en heb meegereden met Paul's 996RS waar deze uitlaat opzit en fantastisch klinkt!!! Omdat het allemaal zo duur is en in het begin andeere prioriteiten had aan de wagen heb ik toch de Manthey laten zitten...nu wil ik eigenlijk ni meer wisselen ...en van dat geblubber heb ik bij mijn weten geen last. Ook qua vermogen een voltreffer!!!

Europipe geeft trouwens ook best mooie vermogenswaarden hoor.

Voor mij zou het tussen deze 2 gaan moest ik jou zijn.

Succes

Yep, was ook bedoeld voor degenen die op zoek waren naar een mogelijkheid om een cup-filter te monteren...

Waaronder ikke dus... deze heeft namelijk het gaatje voor de LMM...