setup:
on my honda civic 1990 D16Z2 SOHC non vtec
stock internals
apexi afc (or apexi AFCII)
450 cc
IC
T3
equal length manifold, 1 1/4 runners
external wastegate (adjustable.)

probably getting everything on the afc @ -40% so the timing wont advance a lot. but the less boost, the more the afc advances, so my Q is: whats the max psi on stock internals with this setup.

 

A good tune will get you 10-12 easy the more you go the easier it will break, run a chip though. A basemap would be safer then a afc :P

 

I think you're a little confused on how the AFC works.

Max psi on an AFC with stock internals on a small T3.......~10psi?
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im also @ hondaperformance.nl (dutch hondaperformance forum)
some1 explained me how the afc really works. ok here it comes. ill translate it from dutch -> englis, zo dont pay attention on the grammar.

imagine ur drivin, and the MAP sensor says the pressure is 750Mbar @ 5000rpm. The ecu says: inject 404msec fuel and 33 degree advancetiming.

if U made an adjustment @ this rpmm, (like +10%) the afc wil raise the MAPsignal by 10%.
The result = the ecu will think you are pushing more on the gaspedal.
basically you'll get yourself in the collum next to the 'stock used collum'. this means, the ecu will inject 472msec fuel and 29,5 degrees advancetiming. INSTEAD of 404msec @ 33,0 degree

this makes clear why the afc advances timing when you put your afc in negative settings like -40%
like when you @ WOT (1035mbar), -30% adjustemnt, the MAP signal will go down, so you end up 2 collums back like normal.
it does gives you less fuel ( 2 collums more to the left gives you incredible less fuel) but it also gives you more advanced timing!!
@ 5000rpm the max advanced timing goes from 21.25 to 25.50 degrees advanced timing, whats not good, and probably cause detonation.

if you use instead of stock 250 cc 450 cc injectors, the difference is like 40%

so @stock idle, 1000rpm 101msec 288mbar
so @ 450cc idle 1000rpm 40msec 288mbar
ignition stays the same. 21,75 degree's cos both collums have the same ign timing.

if jou have less boost like the max 12psi on a afc setup, and still adjust the the signal by -40%, its possible youll endup in a columbar of 865mbar. There's indeed less fuel, so the compensation of -40% will turnout just good.
however ! you ignition will be 29,5 degrees
more boost; and youll end up a collum more to the right, so you ignition will be 25,50 degrees @ the same RPM and the same -40% but more boost. cappiche?


anyone agrees with this?

2pix, 1 of the fuel tables, 1 of the ignition (stock ECU)

 

yeah uhhh..... thats why its safer to run 10+ psi on an afc hack set up, so the timeing does not advance as much, 7-8 psi+30 deg. of timeing is worse than 10-12 psi +25 deg. of timeing.....cappiche?

 

i think you're missing something in your explanation..
the honda map sensor operate 0-5V but max voltage intended to be sent to the ecu is about 3V (which is 0 vacuum) over that voltage it would throw a CEL and go into limp mode. what you're trying to do with the afc hack is send 3V max to the ecu.. 5V reading from the map sensor is something about 11 psi boost (yes the honda map can read some amount of boost) to send 3V to the ECU while your MAP is sending 5V you set your settings in the afc to % -40.. but now your sending less fuel while you need more with some little calculation you'll see you need something around 450cc injectors while stock was 240cc. the timing advancing doesnt always happen for example at wot and your target psi of 11 psi you dont get any advance cause the map reads 5V and you send the ECU 3V it reads the last coloumn like it should the biggest problem is around 0 vacuum when you are about to go into boost.. you may get a advance of even 6-8 degrees depending on the stock timing map of the ECU.. what you should do with the afc are these IMO:
* dont use a laggy turbo so that you wouldnt run along time with advanced timing
* you can use some electronic device like msd btm to retard some timing but it wont help much off boost.. but you can always retard upto 2 degrees at the distributor by rotating it
* while driving use boost with wot.. dont try to cruise around with partial throttle boost at low psi
* use higher octane fuel
* do a wideband and EGT tune with the afc.. try to target a safe AFR and then watch the exhaust gas temperature and add more fuel at revs you get too much heat to cool it down..

i hope it helps.. good luck

 

i will retard it on the distributor: 3degrees
normally im using octane 95, but ill use 98 (is this pump gas in the usa?)
* while driving use boost with wot.. dont try to cruise around with partial throttle boost at low psi
thats kinda crappy, couse it probably will spool @ 3000 rpm and full boost @ 4000rpm?
when i drve 120 km/h (its the max speed on the freeway) in 5th gear im running 3700 rpm
im gonna use the car for dayly use, so partial throttle will be used. how do i solve this problem?

 

dont get on it too much
try to stay away from putting too much load on the engine at those rpms..
well if you do a good tune using a wideband o2 and a egt gauge the way i told above you dont have to worry much about this situation

 

yeah were useing like 91-93 octane fuel over here in the usa, with 95-98 octane you have a lot more room for timeing advancement without detonation, just run like 450's with the afc set to -40 at like 10-11 psi on a moderate sized t3 turbo, even with timeing advance going into boost, you will be fine with that high of a fuel octane, it would still be a good idea to have at least an egt so you can watch the temps.....

 

nice explanations but i think you guys need to go grab a razor and start shaving. I ran the hack for a few months with no problems. 8 psi, every day, stock timing, just played with the vafc till i got it where i wanted it. I ran 93 octane gas and one step colder plugs. Don't be so scared about running advanced timing. Timing doesn't kill motors, detonation does. Plus i know people who have ran the hack for upwards of 2-3 years without problems. However your best bet is to sell it and run crome or uber, or similar