Myths and Rumors: topic #1 Exhuast backpressure

[F 150 Cobra]

Tur loke bota tende riba caya... anto locuaal ta berdad:

ami tur ora mita tende... no pone tubo mucho grandi paso bota perde back pressure

awell ma hasi some research.. ma hanja esaki como cunclusion den cortico

* Backpressure = high torque down low = BULLSHIT
* There is no such thing as "too big" of an exhaust system. When such a claim/observation is made it literally translates to a "too small of an intake" air and fuel wise.
* Key component in the exhaust = header (long tube) and collector + extension design.
* Exhaust system is one that requires pulse tuning NOT VELOCITY.
* Exhaust system is one that requires free flowing characteristics after the headers NOT VELOCITY.
* Characterization of full exhaust systems sizing based on engine HP categories is wrong.
* This is an area in which erring towards the too big side is better. Rather than trying to correct such an error by restricting the exhaust, it's always more productive to correct the exhaust via increasing the engine's intake capabilities.

mi picup su exhuast mes ta mucho chikito.. mester ta dual3" no dual 2.5 mane mitinie awo..

mi mes personal mi a Gain 10Hp riba dyno ora ma habri e cut outs nan dus "open headers"

pakiko bota kere tur dragster ta open headers? pe zona dushi ? nah

[Blitzsoup]

^^^Agreed .

[Lightning John]

Ami tin duel 2.5 ...pero riba mi auto si bo pone 3 inch e ta perde torq pesey hopi hende no ta hacie..pero mi ta mee eens si

[F 150 Cobra]

Ami tin duel 2.5 ...pero riba mi auto si bo pone 3 inch e ta perde torq pesey hopi hende no ta hacie..pero mi ta mee eens si

mita bisa sibo pone dual 3 bota hanja mas power

ami mes ta perdiendo power kumi motor cual ta mas chikito y kiko ta abo.. abo mester bai dual 3 sigur...

[GinoX]

E ponencianan cu bo a copy/paste ta masha hopi general mes!!

Perde/haya power.... na unda riba bo grafiek?

Exhaust pulse tuning basa riba cua testnan di cua institushonan riba ki motor cu tin ki combinashon di piesanan. No lubida cu tur e cos aki di pulse tuning ta perde e momento e topa e mulfflernan.

Cuanto biaha of oranan largo bo ta rev motor PA DIA.

Bo ta band'i rev limiter henter ora, ora bo subi kaminda?

Y kiko esaki ta cuent'i call BS hasi riba un statement hasi door di un hende cu tin un daily driven, *occasionally* raced vehicle.

Ami NO ta core bisa mi ta di acuerdo cu MAYORIA di e ponencianei basa riba mi experiencia. Mi tabtain autonan *daily driven* cu naturally aspirated V8 small y big block unda e momento mi a laga welder un dual 3" exhaust system mi ta perde torque den lower rpm range y cuminsa gasta gasolin.

Si bo kier bo ta ABO ta instala bo 3" system. Ami ta keda cu mi 2.5" dual system riba mi naturally aspirated combination cu mi tin riba mi motor, sea cunnecta cu un H of X crossover section djies patras di e header collectornan. Mesun effect cu e 3" system y HOPI mas eficiente.

Awo, si nos cuminsa papia over di autonan cu motornan cu forced induction.....

[Grumpy]

Bo tin forced induction y normal aspirated, 2 diferente bestia wb exhaust characteristics, mescos cu bo tin diferente muffler pa nan (refractive ehempel: Flowmaster)y straight through ehempel: aeroturbine of e marca haponesnan mane HKS, Trust/Greddy, Apexi etc.

Pocopoco cu internet, tur bestia cu tin computer por expresa nan falta di conocemento. Take it witha grain of salt.

Fact cumi riba turbo, Open downpipe mi twt perde basta low-mid range torque, pero up top mi twt gain 50+hp na 20 psi. That tells you something.
Awo mi tin 4" exhaust, equal length long tube turbo manifold, e ta un compromiso entre bon y malo. Bon y of malo ta sound levels, nan ta haltisimo, pero e ta zona mane ferrari, no un boto di pisca.

[GinoX]

M'a kai den un discushon cu un guy (cu su brothernan) kende antes tbt traha na un muffler shop. E guy aki antes tbt ESUN unda bo tbt bai serka dje pa laga traha herderS pa V8 or un turbo herderS como tambe custom intake manifold pa kalke motor cu no ta un V8. Hasta pa delco ela jeg'i traha intake i exhaust thingies.

E discushon tbt riba e principio di crushbend pipes. E crushbending di pipanan di bo custom made headers ta loke ta ocashona, laga nos bisa e prome set di "restriction". Si bo tin e restriction aki kaba den bo custom made headers pa bo souped up engine, ni con grandi bo exhaust system ta plaka lo bo ta bentando afo construyendo systemanan exesivo di 3", 4", 5".

Ata un voorbeeld di crushbend tubing. Mayoria di nos sa kaba con e ta ziet eruit. Pero toch.... here's the visual. Peep the difference contra mandrel bend.



Check e diferencia den diameter di e mesun grandura di pipa/tubo. Crushbend (diameter chikito) contra mandrel bend tubing. Pa esnan cu por ta no sa, mandrel ta un serie di tools pa assist den doblamento di tubo dependiendo ki tubo di ki diameter ta bai wordu usa.



E toolsnan pa mandrel bend.

[GinoX]

Oh, anto no lubida e pre-mandrel bent tubingnan cu bo ta haja cla kaba. Djies cumpra of manda bestel nan anto ta cla... loke mi kemen ta e zgn. U-, donut- y J-bend. Abo tin di djies buskanan, setnan bow bo auto pa mock up djei corta nan na midi anto welder.

Alternativa eseinan ta, pero door cu nan ta mas caro ta poko hende lo kier saka plaka pa trahacos mane mester ta.