e 30 327 Options

[dodo]

sal all.sunt nou pe forum si am o mare problema.am un urs cu bloc de 2.7 cutie si grup getrag cu 1 in jos volanta usoara ambreiaj sport.are 2 delcouri si 2 bobine pt reglat avansul .intrebarea ar fi suporta un kit de turbo asa cum e sau trebuie decomprimat pt ca automat prin schimbarea blocului a crescut compresia fatade 325.merci .

[mertan]

trebuie sa ai un raport de compresie f mare. poti comprima prin luarea din chiulasa f putin. pistoane forjate, biele speciale si vibrochenul. si daca to e asha poate maresti de la 2.7 la 2.9 sau 3.0 cilindreea. poti face asha ceva cu un stroker kit.

[mertan]

scuze. am citi gresit.

[COObra]

iar motorul de 2.7 e decomprimat din fabrica dupa cate stiu eu... daia parca are doar 125 de cai.
pt comprimare cel mai indicat stiu ca la motorul ala e sa ii pui chiuloasa de 2,5.
dar cum zicea si jaffar pt turbo nu se face comprimare.

[Gabi_323i]

2.7le meu are rc 10.2:1 cu benzina de 95 detoneaza, eu zic ca nu e decomprimat, si inca ceva e stock de la mama lui si are 260 de mii de km

[georgem]

2.7le meu are rc 10.2:1 cu benzina de 95 detoneaza, eu zic ca nu e decomprimat, si inca ceva e stock de la mama lui si are 260 de mii de km

Pai tu trebuie sa mergi cu benzina de 98 minim la raportul asta de compresie. Eu am raport de compresie 10:1 si trebuie sa folosesc benzina de minim 98, asa scrie prin carti.

[316i]

Am bagat 26 de litri de 99 si am facut ~200km in afara. Mi s-a parut sa mearga mai bine. Incepand cu faptul ca motorul mergea mult mai rotund si mai frumos sii chiar mi s-a parut ca a consumat si mai putin. La 100 intr-a 5-a mers constant lua 6 pe econo.

[Gabi_323i]

bine, eu am 11.0:1 si merge bine mersi cu 95 (care in realitate cred ca e ~ 90)

chiar, trebuie sa fac un test cu 98... am tot uitat  :eek:

tu ai 4 supape pe cilindru si chiulasa mult mai bine gandita, ai si vanos deci nu prea are cum sa detoneze

[alex230ro]

Senzor de detonatie? :paranoid:

[Zom]

Senzorul de detonatie (knocking sensor/detonation sensor) "aude" detonatia si poate determina computerul sa intarzie aprinderea pentru a proteja motorul. cu toate ca bmw recomanda utilizarea benzinei fara plumb, acest senzor face posibila utilizarea benzinei normale.

sfat de la ei:
"Run PREMIUM fuel with advanced ignition timing to prevent detonation and engine damage!"

daca schimbati senzorul, dar nu il strangeti bine, semnalul transmis de senzor catre computer va fi mai slab decat normal, fapt care va conduce la detonare.

Si mai departe: au facut dragutii bujii speciale pentru M5, cu senzor inclus:

This extremely high output (507PS) BMW engine runs at high speed (maximum power is achieved at 7,750rpm, and maximum engine speed is 8,250rpm) and with high compression ratio (12:1) and would in any case require spark plugs with an extremely high level of performance. However, in this case the spark plugs have also been designed to act as sensors for a highly sophisticated system which monitors combustion quality and reacts accordingly.

In addition to its normal function within the ignition system, the spark plug electrode is linked to a small independent control unit, the 'ionic current satellite', which measures the ionic current between the electrodes. This current depends on the degree of ionisation within the combustion chamber, which in turn - with the aid of suitable analysis - provides an accurate picture of the quality of combustion. The system can detect the initial stages of both misfiring and detonation, enabling the engine management system to adjust its settings on a cylinder-by-cylinder basis. Incipient detonation for example is countered by momentarily retarding the ignition.

[Zom]

prin prevenirea detonatiilor urmatoare ?!

[Zom]

detonatie = aprinderea violenta a amestecului aer/combustibil. in mod normal, aprinderea trebuie sa se faca "smoothly".

poate era mai potrivit spus "cumintirea aprinderii", nu "intarzierea aprinderii".

dupa cum stim, atat detonarea, cat si pre-aprinderea, nu fac motorul sa mearga mai bine.

[Zom]

detonatia este o forma de combustie anormala care a inceput corect, dar la final, amestecul rezidual aer/combustibil explodeaza in loc sa arda controlat. afectarea motorului vine din presiunea brusc aparuta si care este de mai mult de doua ori mai mare decat presiunea normala.

Benzinele cu cifra octanica mare sunt rezistente la detonare deoarece contin produse care intarzie reactia chimica pe care o numim "combustie". toti combustibilii, indiferent de cifra octanica, au un nivel de detonatie care este atins atunci cand temperatura amestecului rezidual atinge punctul de autoaprindere.

[Gabi_323i]

intarzierea aprinderii sau scaderea avansului la aprindere previne detonatia

[Zom]

intarzierea aprinderii sau scaderea avansului la aprindere previne detonatia

Solutions

Some things you can change, and some you are stuck with. Obvious things to do are get cold, fresh air to your air cleaner, use the best form of charge cooling (intercoolers) you can afford, and work on your cooling system to bring the temperatures down. Get an Air-fuel meter (O2 meter), and if necessary, install a fuel enrichment device. For turbo/supercharged engines water-alcohol injection can be very effective, but the volumes required mean constant refilling and maintenance, so in the long term it is a specialized solution that has a lot of drawbacks.

Spark retard, within limits is the most powerful means of controlling detonation. Traditionally, this has been a manual affair by simply cranking the distributor back "x" degrees, Some electronic devices can retard timing in relation to manifold or boost pressure and other devices offer simple manual knobs you can alter the timing with if an audible "ping" is heard. Many newer cars are quipped with knock sensors that retard the timing when detonation occurs. This form of closed loop spark control where the vehicle's ecu automatically retards all cylinders when detonation occurs, a situation we call "retard all". On a select few modern engine controllers (Porsche, Corvette) the microprocessor is programmed to retard individual cylinders as knock or detonation occurs. The problem with either of these approaches is twofold: First, the OEM carefully maps a complex set of spark curves and only allows a small degree of retard to take place, typically 4 degrees; Secondly, these ecus are highly specific and are not readily adaptable or programmable for other applications.

[dodo]

nu e de serie e chiulasa de 325 i si bloc de 2.7 teoretic are aproape 200 de cai

[Zom]

http://bmwnut.blogspot.com/2006_02_26_bmwn...ut_archive.html

cica poti ajunge pana la 220 cp daca pui lucurrile cap la cap cum trebuie

[Gabi_323i]

nu e de serie e chiulasa de 325 i si bloc de 2.7 teoretic are aproape 200 de cai

practic are 165

[Sorin]

de unde sti?

[dodo]

adica mai putin decat 325 i?nu cred ca te refereai la cai la roata