just got an Apexi SAFC2 and need some help with it.. i dont understand it on the setting and stuff like that if someone can help me with it that well be supper.. lil something of what the car and my set up it an 1987 rx7 s4 im running a N/A turbo set up got some 1200 cc injectors and also got some s5 low MP injectors i think there like 550 cc or so... and also running a E-Boost boost controller.. my number is (575)-200-9715 so can someone help me A.S.A.P thanks im going to work on the car all day tomorrow so call me or text me

 

this is the first time doing a thread here so i hope i did it right..

 

SAFC section: https://www.rx7club.com/super-afc-123/

1200cc injectors are WAY too much for an AFC to possibly control. That's almost 3x the size of the stock 460cc injectors, and more than double the size of turbo 550cc injectors if you're using a TII ECU (which you should be). An AFC has something like a 50% maximum correction, and you would need much more than that to tame 1200cc injectors.

Something else to keep in mind is that altering the AFM signal to subtract large amounts of fuel (negative correction on an AFC) will advance ignition timing. This is very dangerous on any turbo engine, let alone a high compression turbo build.

 

yep, his whole approach to this is a recipe for a toasty motor. you'll have to wind up pulling out about 15* of timing by retarding the CAS which will affect all but your top boost level power outputs.

those injectors are just way too much for what you need unless you have a mid framed turbo on the car, which is an even worse idea for a piggybacked n/a->turbo. 720/720 is about as big as you should go and is more than enough for the stock turbo.

 

okay thank for that info i didnt know that.
so change of plans then can i use my n/a s5 vert injectors they are telliing me that i cant do to that my car is an s4 harness so i got low impedance injectors and they say that the s5 are high impedance is that true if so can i still use the on the set up??

 

who are you getting advice from? because you need to look elsewhere.

86-87.5 - low impedence rectangular center lug
88 - high impedence rectangular offset lug
89-91 - high impedence oval connector

all non turbo = 440cc
all turbo = 550cc

the ECU needs to see ~12-13 ohms from the injectors.
86-87.5 had a resistor block in the engine bay by the RF strut tower to up the resistance to the proper ohms due to being low impedence injectors.
88-91 had the proper resistance injectors and no resistor pack.

so you need to find out what harness you have for the injectors to plug into the figure out what injectors you need.

you can modify the harness to run either type of injector on any series car by removing the resistor block and soldering the wires all together but the injector plug locating lugs will need to also be modified to actually let the harness plug into them, or cut and solder in new injector connectors.

no you can't use vert n/a injectors, they're only 440cc's and are too small for a turbo setup even at stock horsepower levels.

since you listed this on the local forums also i'm thinking you have moved to vegas, if so you might want to consider just paying someone to do the work for you(of course i have the only rotary shop in town though so you're choices are limited, or find one of the locals who can help in person with it).

 

well the info i was getting it from someone in vegas. but the reason i put on the local is because i live in vegas before now i live in new mexico in a small town that they dont even know what an rotary engine is that why i post on vegas forms. but i think i found the problem is my injectors. im running some 1200cc so now i'm on the look for some 550 or 680cc