Guys,

I have 440cc injectors and I'm considering moving up from a 7psi to 9psi on my CTSC+AC, looking at my GEMU logs its 75% duty cycle at redline, below this is obviously tapers up. My AFR is around 12.2 throughout in vtec @4k - A friend said at my boost levels, UK weather and way I drive i could goto 12.4 MAX afr but still have to taper down at redline.

My question is would i 'roughly' have enough headroom to run 9psi or would it push past 85% DC?, 85% is what i consider the limit (without going static) thus i wouldn't like to go any further (considering where i live i cant hoon the car a lot), what % would it likely go upto?

cheers

 

i would upgrade your injectors to id725 or rc 650. maybe even just step up to a id1000 or bosch 900 for future upgrades. it sounds like overkill, but thats what i said when i was running 650's lol. now i am on bosch 900's and wish i had just went id2000

 

Thanks.

Sure i can always put bigger injectors in, but i just want to know if there is scope duty cycle wise on the current ones?

 

i feel you will be pushing them. rc engineering has a fuel injector calc, and it will show you that at stock base fuel pressure, 440's dont do much. lemme dig up the link.


http://www.rceng.com/technical.aspx

its ballpark of course. but helps.

 

8psi should be fine. 9psi would be pushing it past 85% i'm pretty sure. Doest take but a little time to throw on the pulley and start tuning WOT/open loop with your buddy to see where you’re at though AJ. Might get lucky. Could bump up the static fuel pressure just a bit. 50-55psi? But then you have complicated your tune, with likley needing to get into closed loop calibrating on your emanage again. I think it could all be done though. Might want to bounce this off Brad.

 

Could do Brad.

Do you know if a comptech 4.0" pulley will net me 8psi (7.5psi +ac).

According to this it should???

For Comptech:
4060400 Standard AP1
4060395 4.25inch -------------------- I must be running this stock AP2 pulley on my ap1 to net 7psi (6.5+ac)??
4060390 4.0inch(7#)
4060385 3.5 3.35inch
4060380 3.25inch
4060370 3.0 inch

Thanks

 

Yes i saw 8psi at 9k with the 4"