NA vs NB - Stock injectors and fuel pressure
#1
NA vs NB - Stock injectors and fuel pressure
Hey,
I though about the NA vs NB injectors and fuel pressure, I used to think that the NA and NB have about the same flow size injectors 254 vs 265 @ 3 bar, so they should support about the same boost. But lately I've found out that the NB fuel pressure is 4 bar, meaning the injector is running at 306cc so on the NB the stock injector can support a little more boost - I saw NB running almost 200whp on the dyno with stock injectors and stock pressure - now I understand why...
Just a though
Elior
I though about the NA vs NB injectors and fuel pressure, I used to think that the NA and NB have about the same flow size injectors 254 vs 265 @ 3 bar, so they should support about the same boost. But lately I've found out that the NB fuel pressure is 4 bar, meaning the injector is running at 306cc so on the NB the stock injector can support a little more boost - I saw NB running almost 200whp on the dyno with stock injectors and stock pressure - now I understand why...
Just a though
Elior
#6
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This revolution came when I needed to setup an ECU for a turbo NB - the stock pressure was not 3bars like on my NA - so in order to get correct numbers from the ecu a correct fuel pressure is one of the parameters.
Wouldn't you agree that a stock 4bar pressure is uncommon ?
Wouldn't you agree that a stock 4bar pressure is uncommon ?
#8
Not at all. 4 bar pressure is very common for returnless fuel setups. The difference is at 1 bar of positive boost pressure, the pressure differential over the injectors is now 3 bar. I believe in an NA, with the vacuum referenced FPR, the pressure differential is always 3 bar.
NA 3bar
NB 4bar
Am I wrong ?