Worth it or not

[Lycan6]

I have a 1397 gen I with port and polished head and cams 380/380. My question is whether or not its worth it to add s2000 injectors or not. I'm not going to spray it but may do a gen II crank this fall. Is there anything to be gained from the injectors. That's for all feedback in advance.

[MLSDUKE1]

Negative. There will be no real gain except for you knowing you have the injectors. Your stock ones are just fine

[m_ridgeway]

No, look at your fuel pump first. They dont put out a lot of volume.

[Lycan6]

Negative. There will be no real gain except for you knowing you have the injectors. Your stock ones are just fine

No, look at your fuel pump first. They dont put out a lot of volume.

Thanks for the responses. I guess i will leave that $400 in my pocket and put it toward the crank.

[bisquit61]

This is a good question. I have a similiar setup,cams are a little different, but when I get in the upper rpms at the track I get a FI light that does not hinder performance but I wondered whether it is needing more fuel. My mechanic says it would do better with bigger injectors but I've also heard from others that I don't need it. So I have left it alone for now but I too am wondering what is right or wrong.

[m_ridgeway]

This is a good question. I have a similiar setup,cams are a little different, but when I get in the upper rpms at the track I get a FI light that does not hinder performance but I wondered whether it is needing more fuel. My mechanic says it would do better with bigger injectors but I've also heard from others that I don't need it. So I have left it alone for now but I too am wondering what is right or wrong.

Logging fuel pressure or pump duty cycle would give a good idea where to start.

Everything I've read suggests the pumps in these bikes are weak. Ill be doing an external pump when I do my motor. If you can keep pressure and still maxing out injectors, then its time for injectors.

[teezy]

Your stock injectors are fine!!! The hayabusa intank pumps are crap!!! They have gone out on every busa I have been around.. We have sprayed with stock injectors up in the 250-260whp range... If you have plans of spray then definitely pick up some S2K injectors but you will need someone to reflash the ecu for them.

Replace the pump and dont waste your time trying too put a stock one back in it..... I put a BOSCH 69420 intank in my buddies busa and it fixed everything.. It is basicly a drop-in 255lph intank pump...

[D-max15]

teezy...

correct me if i'm wrong, but the fuel pressure regulator mod must be done to make 250-260 horsepower. this would raise fuel pressure to 55-58 psi....

[teezy]

teezy...

correct me if i'm wrong, but the fuel pressure regulator mod must be done to make 250-260 horsepower. this would raise fuel pressure to 55-58 psi....

On a stock pump you have too crank up the fuel pressure to make that much power...the stock fuel pump is weak and doesnt move alot of volume.. the 255 intank is a serious pump.. it will move crazy volume!!


To give you a better example.... I have a busa in my garage thats a stock bolton gen1 with a 45shot on it... For safey we changed the stock pump out for a 255 intank.. We dropped the values in the power commander from 40-50's to 12-17on dope.. and honesty that was setting it up alittle rich to keep it safe.... stock reg and injectors.