Tuning performanta motor

[unariciflocos]

Asa, urmeaza sa fac o conversie la motorul de pe Pejoul meu la clapete individuale si ecu de injectie si aprindere standalone cu feedback wideband lambda.

Arata cam asa http://www.westfield1800.com/images/mar ... ies-05.jpg si costurile de conversie sar de 1000 de Euro. Castigurile ar trebui sa fie pe la 30 de cai pe un motor stock 1.6 16v si ceva mai mari cu un set de axe si comprimarea motorului. Nu vreau sa incep sa arunc cu cifre si castiguri, dar va fi un castig de putere care se simte.

As fi curios daca ar fi cineva interesat de asa ceva.

[sfert]

Asta e cam ultima chestie de "tuning" pe care io poti face unui normal aspirat , daca ai banii numai sta pe ganduri , inafara de faptul ca arata deosebit de bine chiar se simte modificarea . Doritori sunt comvins ca exista dar ca si in cazul meu banii sunt problema .

[unariciflocos]

Pai la mine am stabilit deja ingredientele care includ thrttle body-uri de 42mm, 2 bancuri de injectoare, ECU standalone si Innovate LC-1 wideband lambda, o axa de admisie suparata si o fulie reglabila, compresie 11:1 si un motor complet fresh.

Retata asta e testata pentru 190 de cai pe motorul meu 1.9 Mi16 si sper sa fie functionala pe Aprilie. Daca cineva e interesat ma ofer sa fac o asemenea conversie cap coada, evident dupa ce il fac al meu si contra cost pentru ca timpul meu e pretios .

Ultima oară modificat de unariciflocos pe 04 Dec 2009, 16:12, modificat 1 dată în total.

[RHOBY1305]

ai modificat ceva la focusul pe care il detii?

[unariciflocos]

Focusul care il detin are un motor tddi de 75 de cai chipuit, consumabile schimbate regulat la 7k km, arcuri weitec -55 mm si jante de 16 cu gume 205/50. E deosebit de stabil pentru ca odata cu coborarea mare mi s-au schimbat si unghiurile de cadere (nu stiu cum se zice exact, dar stiu ca in engleza se numeste negative camber) care ajuta foarte mult stabilitatea pe viraje cu costul uzurii interioare a anvelopelor.

Modificari extinse fac doar pe cealalta masina, un Pejo 205 care-l folosesc pentru curse si VTM.

[adyamg]

Indraznesc sa spun ca o cadere negativa nu iti aduce neaparat o stabilitate mai buna. Adica e logic ca atata vreme cat circuli doar pe un umar al pneului sa nu mai ai aceeasi stabilitate ca atunci cand rulezi pe tot profilul anvelopei.
Toti cei ce doresc sa coboare masina fara sa faca compormosuri in geometrie folosesc asa numitele camber kits.

[unariciflocos]

Se sacrifica asa zisa aderenta la mers drept pentru mult dorita stabilitate pe viraje.

Pe viraje masina se inclina spre exteriorul virajului datorita fortelor cetrifugice si masina face transfer de mase pe rotile din exterior. In acelasi timp acele roti, datorita inclinarii masinii, trec de la cadere negativa la cadere neutra, deci calca perfect perpendicular pe asfalt si pe toata suprafata. Impreuna cu anvelope cu talon jos si pereti laterali intariti se obtine o stabilitate extraordinara.

Rotile de pe interior se inclina si mai tare spre negativ, dar nu conteaza pentru ca ele nu au aderenta. Creste uzura la anvelope pe interior, dar nu exista castig fara compromis.

Revenind la topic, o sa inteleg ca nu sunt amatori de asa ceva. Voi reveni cu rezultate de la motorul meu.

[sfert]

Bafta la modificari

[Maddogul]

Hello
Si eumerg pe acesti pasi deocamdata doar am luat doar o rampa de Yamaha R1 din 2008 cea cu injectoare Mikuni de 46mm parca , ma gandesc la un OMEX sau de ce nu la un megasquirt dar mai discutam
Cu Stima

[unariciflocos]

Pentru ca nu intodeauna mai mare inseamna mai bun, 46mm mi se pare cam mare si pentru un motor de 2 litri. Cred ca vei sacrifica mult din cuplul la turatii sub 3000 - 4000 si vei avea un motor destul de greu de folosit in viata de zi cu zi. Poti compensa asta cu un banc de injectoare mai mici in chiuloasa care sa mearga sub 4000 si apoi pentru forja sa preia sarcina cele din throttle body-uri.

S-ar putea sa ma gandesc si eu la body-uri mai mari avand in vedere ca am revlimit la 7500 si cutie scurta si mi-e util plusul de putere dat de body-uri mai mare la turatie mare.

Atentie foarte mare la lungimea si forma traseului de admisie. Jucandu-ma cu lungimea traseelor am vazut diferente de 25 Nm pe dyno la un motor aspirat, ceea ce e enorm. Asta am facut si am vazut cu ochii mei pe un set de 4 carburatoare individuale de R1, dar principiul e acelasi. Oricum cine stie, poate erau alti factori care imi influentau rezultatul.

Despre Omex, Emerald, KMS nu stiu ce sa spun inafara de faptul ca au pretul cam prohibitiv, dar eu imi incerc norocul cu un kit de Megasquirt 1 V3 cu LC-1 si bobina cu 4 iesiri wasted spark.

Oricum imi creste inima de cate ori vad in Romania pe cineva pentru care tiuningu nu inseamna stickere kitchoase si zeci de cai din filtre si tobe "sport".

[unariciflocos]

Revin legat de body-urile de 46, la turatii mici debitul de aer e mai mic si viteza aerului e implicit si ea mai mica si de acolo eficienta volumetrica mai mica.

Citeste asta:
It’s possible to obtain greater than 100% volumetric efficiency in a naturally aspirated (non-supercharged) engine by using tuned intake/exhaust systems. How all this works isn’t all that complicated, but it takes a while to explain it properly. I think the first use of tuned intake runners were the vertical velocity stacks. They were generally of a length that put the open bell mouth somewhere around 15 to 18 inches above the back side of the intake valve. Although both the length and diameter of the runner are important, the length is what determines the specific rpm at which the runner is tuned to provide peak efficiency.

The velocity stack utilized the fact that air is a compressible fluid to produce its boost. At wide open throttle, with the engine turning at high rpm (the rpm that the intake is tuned for), a column of air is moving at a high rate of speed down the intake pipe while the intake valve is open. The column of air moves toward the cylinder in response to differential pressure; the pressure in the cylinder is lower than the pressure at the open end of the velocity stack. When the intake valve closes, the inertia of the column of air causes it to continue moving down the intake tube, stacking up against the back of the closed intake valve, causing the intake air to compress, and creating a higher pressure right up against the valve.

Now if the high pressure air sitting at the intake valve would just stay there until the valve opens again, life would be very simple. Only it can’t, because the pressure is now lower at the inlet to the runner. So the high pressure air bounces off the closed valve and tries to move backwards toward the inlet. Since the valve is closed, the entire column of doesn’t really start flowing backwards; instead it is more like a high pressure wave propagating back toward the inlet. This high pressure wave (or pulse) leaves a low pressure behind it, and when it finally reaches the inlet, the pressure at the inlet is now greater than the pressure in the intake tube. As a result of low pressure in the tube, air starts moving back into the tube, its inertia causing it to stack up against the intake valve again, which is still closed. If the engine is turning the proper rpm (whatever the intake tube is tuned for), the intake valve opens when this higher than ambient pressure is present at the valve.

Some of the design considerations are pretty obvious. If the diameter of the tube is too large, the velocity of the column of air will be too slow to create a good inertial pulse, or reflected wave. If the tube is too narrow it will restrict the airflow and cause a performance decrease. The length of the runner determines the rpm where any boost effect will occur. Earlier it was noted that the typical velocity stacks on old race cars were around a foot long. Since I think the reflected waves that set up inside the runner propagate at the speed of sound, I think the length is such that it is three times as long as the calculations would indicate it should be. These older types used a third order harmonic, or in other words, several of these waves would be bouncing back and forth inside there at any given time. Maybe some math people here can sort out whether this is part is correct or not. I think they used to use a foot (or foot and a half) long for an rpm around 5 or 6k. It seems like there used to be a formula that was used to make some sort of preliminary “length to rpm” calculation. Testing would still be needed to fine-tune a particular setup.

The way it was explained to me, using a length tuned to the third-order harmonic gives a very deep peak when you hit the resonate rpm, in other words a big kick. The problem with this is that it is not effective when you get off of (above or below) that rpm for which it is tuned. The much shorter stacks that are common today, and the tuned induction systems seen on a lot of cars must be using first- or second-order harmonics, I’m not sure, but that would have the purpose of making the thing effective over a significantly wider rpm band, but at the cost of not producing quite as high of a peak boost.

Exhaust systems are similar, but I think they are not quite as twitchy to get right as the intake runners are. The exhaust pulses have a significantly higher pressure differential, or power pulse, that you are dealing with, to begin with. But the process is similar, except the thing is tuned to have the exhaust valve open when the low pressure pulse is present at the back of the valve.

[Maddogul]

Revenim sunt Mikuni de 45mm :d
Cu Stima

[unariciflocos]

Ok... nu inteleg ce vrei sa spui cu asta, dar mi-am amintit ca body-urile de GSXR au al doilea set de clapete care inchid partial la turatii joase ca sa accelereze aerul care intra in cilindru.