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Ey,

i got a mate that suggested i put bigger injectors in my rb20. At the moment i got std injectors, with highflowed r33 turbo, front mount, fuel reg, fuel exhaust system, pod filter. Im planning to replace the std ecu with microtech in the next 3-4weeks. IS it a big difference with bigger injectors? if so....in wat way? and if 800cc are too big...hopw big should i go?

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Im in the same boat but with an RB25DET.. I'm getting a highflow turbo, FMIC, Walbro pump and Haltech ECU fitted soon and was wondering wether to put a fuel pressure reg or get larger injectors.... $250 Vs $900 :( few tuners said the highflow turbo would max at 240 - 250 rw/kw which the stock injectors with rising rate FPR have achieved on some R33's at 90% duty...

Cheers

With larger injectors and larger fuel pump, the standard fuel rail pressure will be fine... theres no need for an after market FPR. You only need a rising rate FPR when the injectors are closing to their max duty... 800cc's are good enough for approx 800hp... 550cc will be a better option cause they will be easier to tune...

Edited by QRI05E

Probably GTR injectors + FPR would be your best bet... 480cc and i "think" they are direct drop in cause both the RB20 and RB26 are both top feed if im not mistaken?

Otherwise Nismo 550cc will more then enough and you wont need a rising rate FPR

Cheers

Edited by QRI05E

Well once you tune the ECU, any size injectors can be used for example at 250rw/kw the Nismo 550cc might reach a duty cycle of 65% where the Nismo 800cc wil only reach 50%. But this also means the larger the injector the harder it is to tune therefore you should only ever get injectors to match your power goal...

250rw/kw = 550cc max otherwise would be overkill

GTR injectors are 480cc so theoretically will support 480hp (80% duty) at the fly wheel. Therefore 480hp - 30% (drive train loss) = 336rw/hp = 250.56rw/kw (80% duty)

Hope this helps

Regards,

Sarkis

For a max power of 250rw/kw, Yes 800cc are an overkill... Dont get me wrong, they will still work fine but wont be utilized as well as the 550cc in other words you wont be using them to their intended potential...

Cheers

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