1SxyRXy

well after i get my new engine i have a few questions. im planning on getting DP,MP,FCD and some 720cc injectors. what would be best to go with . walbro fuel pump or a apexi AFC. what do u think would best? and i do know that with getting the injectors i would obviously need the fuel pump to put the injectors to good use. soo... should i just try to get the pump and AFC at the same time??

-neil

NZConvertible

You're installing a full exhaust, but you don't mention any wastegate mods to control boost. This combined with your current
intake mods will cause serious boost creep, lean mixtures and detonation. Upgrading the injectors and drowning it in fuel to stop the detonation is a very crude way of doing things. Even if you control detonation, the high boost levels will eventually kill a stock turbo. You're much better off ensuring boost is kept down around 10psi. That way you can forget about the injectors, you won't need them.
However you need that pump! That's the weakest link, not the injectors. Get the S-AFC too so you can take it to a dyno and fix any areas that are too rich.

1SxyRXy

i looked at porting the wastegate. but nobody says anything about S5 turbo's. anyone have a link on how to port S5 turbo's??

NZConvertible

Oops, I missed you have a S5. The S5's still have boost creep problems, just nowhere near as bad as S4's. As for porting, it's exactly the same. All you're doing is enlarging the holes as big as the flap will allow.

MiyaKokujin

Get the fuel pump. I recommend a Skyline GTR pump. Now that youve solved the weekest link, you are still limited to the amount of fuel delivery. Try running bigger fuel injectors in the secondaries. 720cc-850cc is good enough. To get everything calculated right, run a stand alone fuel management system. Apexi's AFC is cool, but Im gonna go with the Apexi Power FC. It replaces the entire ECU and you wil be able to control all fuel, intake, timing, and other parameters. I love being in Japan. They have the best toys!!

mr_vaughn

iTrader: (1)

i have a street port 3mm apex seals ;hybrid stage 2 turbo ,stock wastgate ,
the best mods
pulling the CAT and putting a Racing Beat 3" presilenser
took boost from 4# to 14#
on a 89 T2

NZConvertible

Like I said above, this isn't necessary unless you can't control boost creep or you've significantly upgraded the turbo. The stock injectors can flow enough fuel for ~300hp, so replacing them isn't going to gain you anything if you're only making 250hp on the stock turbo. Injectors should only be replaced when they actually run out of capacity.