Piggyback (SAFC) vs. Additional Fuel Injectors (AIC)
 

What are the advantages to each of these systems? In perticular the Apexi s AFC and the HKS AIC. I am looking for low 13 sec. ets. I will get a walboro fuel pump, and either larger injectors for the afc or just additional ones for the aic. I am considering a to4 compressor on my stock or maybe a s5 turbo. What size injectors will I need and how much power to get 13s? I cant afford an ems. Also, would the first gen afc work for me. I dont have much access to a dyno but I know a guy that will let me borrow his wideband o2 sensor. Will I be able to tune it properly with this? Also does the t04 comp. upgrade sound like it would support 13-possibly 12 second runs? Thanks

dude low 13s can be accomplished on the stock turbo with a boost controller and some type of fuel controler obviously a bigger fuelpump, bigger injectors, and S-AFC, very much a pain in the ass to install additional injectors, oh I almost for got traction!, make sure you change out you diff fliud and get some slicks, I ran a 14.2 with my mods with a broken diff mount, with my tiny tires, and I had no traction, with slicks I prolly would see mid to low 13s, once I have everything tuned properly.

Changing fuel injectors is a bitch ??? Damn, I was actually gonna do that myself, is their a site anywhere with directions ?

changing the injectors isn't that bad, but getting the car back together is. :D Actually, if you've ever had the intercooler off, you're about 1/3 of the way there (the easy 1/3). After that, you just take off 5 ( i believe) bolts holding the manny down and you can now see the injectors and fuel rails. If you do it yourself, make SURE the O-Rings seal properly, and if you're using different sized injectors... well I won't even bother to tell you that they have to be in the right rail (well I guess i just did) :D In any case, getting the manny back on is a little tough cause you have to make sure the mess of vac lines is all plumbed back in properly and the coolant hose going to the bottom of the manny is a bitch to get on. I've tried a number of thigns to get around that hose, but it looks like blocking it off is the best idea to avoid the hassle of connecting it, and I dont' want to block that one off. Good luck, and I'm sure you can find a writeup somewhere.

thanks

13 secs is easy on stock injectors....

Resto, you forgot to mention the evil coolant hose that holds the upper intake to the rear housing. FUCK THAT THING!

I was talking about actually adding additional injectors, like on the top of the intake mani, I've seen it done, but a major pain, changing the injectors is no biggy, just got to be compitent

Well I just swapped the motor so I can install different injectors in a snap. But how high can I raise the boost w/ out new injectors or a new turbo. Ill get a walboro 255 pump. What would be a safe boost level? What does the stock turbo max out at? Thanks

Well I would go for an upgraded S5 turbo. Contact Bryan @ BNRsupercars.com and he'll hook you up. I told him I wanted like 350hp and he said to go with his stage 4 upgrade and I'd need 4 720cc injectors along with a larger pump. But by the time I do all that I'll have alot better intercooler as well. So don't forget getting a better intercooler.

And the max boost level really depends with each car but I would say 10psi with a walbro rewired would be fairly safe. To be certain you need that wideband though. But that 10psi isn't going to get you very far into the 13s.

I'd say, if you have a fuel controll 10-12psi, stock ecu with no piggy back, only 8-9psi

so the stock injectors max out at like what 10 psi?

to be safe yes