Hi,

I have a very specific question, only experienced people will be able to reply so please don't bother to reply "things you have heard" thank you.

1000cc injectors
stock evo9 fuel pump
98oct
Injector max duty : 68%
AFRs at 8000rpm : 10.2

I'm not running lean nor max the injectors as you can see.
Is there any possibility that somehow (ECU?) the fuel pump flow still limits max power ?

I just can't seem ro reach the same numbers anymore after 6000rpm after removing my way too noisy Walbro and it's the only thing that changed.
Logically I should have been running leaner or have more injector duty but I don't, actually my max inj. duty lowered 1-2% after putting the stock fuel pump back in.

Weird.

 

Did you adjust the tune? A super rich AFR like you have will take away a good bit of power.

 

I can make them whatever I want even 13 or 9, the goal here was to show you that clearly the stock fuel pump is not making my mixture leaner.
It could have been that, but it's not that I've made comparisons with various afrs.

Hmm I guess my hp limitation comes from something else...

 

If anyone is interested I found my problem, stock intercooler not up to the job, had nothing to do with the fuel pump.
I guess the hot air also explains the weird rich afrs I was getting.

 

post back in a month or so.