Kelimutu

I have an S5 -89 with slightly bigger turbo (see my sig for all mods) and with only FD pump and stock injectors, i wonder if anyone have managed to tune the S-AFC to higher levels using only the stock 4X550cc´s?
I will add 720cc later, but can i expect any gain in dialing the S-AFC for the stockers, or is it a waste of time?

Some one suggested using a RRFPR to try to get the most out of my current setup and stock injectors, but i am thinking of going for the 720cc´s right away.

Any thougts? Anyone using the S-AFC with stock injectors and still notice any kind of improvement?

PS: I have a boostcontroller installed, for the moment it is tuned down to the lowest setting giving me a steady 7,5 psi boost, but i want to turn it up.... but before i get to a dyno i am mostly curious what to expect with my current setup! DS.

Kelimutu

bump

Kelimutu

Noone with an S5 T2 have done this? I really need information from someone with experience. How does the car behave with 720cc secondaires, FD-pump and S-AFC? This is maybe the most common mod som please can someone respond!?!?!

Kelimutu

Take it easy guys, not everybody at the same time!!:-)

FD4S

FDs use 2x550 and 2x850 injectors, and on modified outputs, they tend to struggle with the fuel. If you were hoping to use the AFC to increase the fuel flow, be careful of reaching 100% duty cycle on your 4x550s.

I can't comment on the car's behaviour with your proposed setup, but the point worth noting is to use the AFC as a fine-tuning device (preferably to decrease, rather than increase the fuel) so as not to hit 100% duty cycles.

Try directly wiring up your fuel pump (with thicker wires) and then utilising a FPR at a higher pressure, then using the AFC to reduce/adjust fuel levels. Hope I helped.

Kelimutu

Tanks for replying. I have a FC, and i already have larger pump rewired - i am looking for someone who has installed the S-AFC before upgrading to larger secondaries, someone must have done this even so for just a couple of weeks, its hard to imagine that everybody install S-AFC and injectors exactly at the same time.... I wanted to drive with only the S-AFC first to so how it works, now i learned and what to dyno to se some real numbers but i just needed to know if someone have done this - in 2 months i will know myself but i want to know now!!!

Second Gen

iTrader: (4)

Holla,

I have a 1989 TII with a Stage one BNR tubo that is running very well. I am running the stock 550's on the primarys, and a pair of Greddy 720's in the secondary positions. I also have a modified TID and a complete RB 3" exhaust. The setup is very fast (Breaks loose @ 4K RPM's in 1st/2nd and sometimes in third). I am going this Friday to the RX-7 store (Locally) and they are going to tune the SAFC II to the fuel system with the Wideband. The only item I don't like with my setup is a wierd pause when letting off the accelerator after a heavy boost (Almost as if the BOV is doing something strange.) Good luck with your quest.

The rest of my mods are in my sig.....

David

Kelimutu

David, what happened on the dyno?

djvnrx7

STOPP!!!!!!!!!!!!!!!! OK I HAVE A 88 T2 WITH STOCK TURBO listen if you use 550 primarys and atleast 720 secondarys you can get awat with it but i personaly still run a little lean through 4500 and 5500 rpm i know this because i have a fjo widband in the car i would not bump up the turbo at all i am maxed at 50% + at thies 2 rpm settings , you can get away with it for a while but eventually you will have to go haltec lol which is my personal next step , in closing when your tuning with the super afc you can get it close and stay safe but thier will always be a little sputter when the secondary's kick in at about 4000rpm so it make you drive like a luny toon or just tool around keeping the car under 4k so you have to make the dicision stay cheap and drive or spend cash and wail GOOD LUCK i stayed cheapo therfore i am about to wail

Kelimutu

and it is defenetly doing it sjob, even though i only have stock injectors, the S-AFC is working very well and i actually turned it down on low and top end but up in the middle range.... i did not boost moore than 0.5 but had 212 bhp at only 0.4 bar.... wich will give me 260 bhp with 0.7bar, but something happende, the lmm went craxy so we could not proceed - i will get back with more info!

sirx7

what is rrfpr/lmm? and other short little acronyms you are using i awaiting my safc2 i have similar setup running kinighsport ecu and kinghtsport engine.. right now making 10.3 psi full boost at 4000rpms u hear tick tick at 5500rps am and i let of switch gears..no bossting in fifth way too fast as it is

Kelimutu

what is rrfpr/lmm - rising rate fuel pressure regulator, lmm is swedish.... airflowmeter AFM in english!

RETed

Stock 4x550's are only good till 250bhp.
Be careful going more than that.
RRFPR might be a quick fix, but with the 720's in the near future, don't bother with the RRFPR.


-Ted

SureShot

True in warm air, but when the ambient air temp gets down in the 30's, the stock injectors max out even sooner.

slimjim16

Ok i got a question im running stock injectors right now and i just picked up a SAFCII to tune with, now as for my mods new engine,stock turbo/wastegate(no boost creap..so far), FCD, full 3" exhaust, 3" TID, Walbro 255 fuel pump, Blitz blow off valve, air pump removed(FACK EMISSIONS ) Im lookin for no more than say like 250-300 horse as it is(dont think ill reach 300 anyways) , im not looking for top performance(at the moment ) i just wanna know if its allright to use stocker inject. until i upgrade my turbo? and i will be goin on the dyno to tune, and professionals will be doin the tuning.

also how much are 720cc injector secondarys? ballpark.

SureShot

720's - $50-100 each
Also consider rewiring the fuel pump.
The stock wiring is just barely enough to run the stock pump.
This also happens to be my next project.