Yep this is it. One year later. BFTD

 

no ****. everyone here is talkin abot bost between 5 & 10 psi. im planning on running 440 or 450 cc injectors on 12lbs of boost. will this hack still work for me? and where are these graphs at cuz i do so much better w/ pictures...
-cam

oh yeah, im going to be running a t25 w/ .63 a/r ratio if it matters


[Modified by bad 2 the B-ONE ej1, 9:18 AM 3/3/2003]

 

The ignition timing on the AFC hack at 8-10psi shouldnt really be any different then using a FMU at the same boost with a missing link.

Why? The ecu is seeing the same map voltage on either setup. And everything else is the same..like TPS etc.

liam

 

Yes..when i lived in denver there was about a 3psi air pressure difference between denver and sea level. Running -25% on 310 should do pretty good for your setup. Very cool With 450cc and -40% you could get away with almost 15psi of boost! haha

liam

 

yep it was...pretty cool huh? One year later. Ive run into sooooo many people running this type of fuel system now.



liam

 

The only limit on boost is what you have your afc set at. The more negative your afc fuel value the more boost you can run. -40% can get you 11-12psi *at the limit* without a CEL.

To run things safely, i recommend running a little more fuel pressure and a lower afc value if 12psi is what you want...that should give you a little extra breathing room just incase you overboost. Raise your fuel pressure 5psi at a time and lower your afc until you find a nice setting. Make sure you have a wideband or egt or something to tune off of.

liam

 

What is a DPDT pressure switch? sorry, for the stupid question, new to turbo scene. thanks.

Oh yeah, btw, what about backing down the timing in high rpm, full boost situations.
i was going to try and buy the zdyne Gold SECU, but that is a frickin grand. oh well this is a lot cheaper and thanks a lot to the people who discovered this hack, you have saved a lot of people a lot of money and headaches.

I read the whole thread and i am super stoked about doing this setup, but i would like a final and complete list of the stuff needed. Thanks peace.


[Modified by darkracer, 5:44 AM 3/4/2003]

 

DPDT = double pole double throw switch, forces the ECU to think you are at WOT so you run open loop. Smarter than your average bear.

And by the way **** the AFC, most guys run a constant across the board cut anyway which can be achieved with a $2 potentiometer from radioshack. If you know which end of a soldering iron to grab when it's hot you can hook up a $2 hack and save $298


[Modified by filetofit, 6:50 AM 3/4/2003]

 

can i use that on my B16 A2 97
i made my own turbo kit and when i run cel turn on (map sensor ?? )
if i use this system my problem goes on ??
what i will nedd ??
so if i use this i will not nedd missing link rigth??
The AFC that you mention are V-afc or S-afc ??
thanks for yours attencions
sorry for my bad English
best regards


[Modified by _VTI-R_, 10:32 AM 3/4/2003]

 

Is there a write up on the potentiometer method anywhere? I'm having the most difficulty deciding on fuel management and would love to find a site that discussed a bunch of methods with pros/cons of each. Any of you gurus have something written up on the topic?

 

damn is that why i have hunting problems (rev goes up and down and up and down without moving my foor on the gas pedal) from 2-3k??? how and why would this cause advance timing if it does??

thanks,

chris

 

Oh, really? I drew this picture for you in paint.



I don't see that **** being the same at all. Most Honda engines retard ignition far more approaching the final column due to just about everything being a higher CR than LS... the above picture is a best case scenario.

FWIW, most ECUs hold different values in the second to last column instead of cloning values, but this map is an OEM 90-91 PR4 and those things are a bit non-standard.

 

You know I thought they had one at c-speedracing but I couldn't find it.

Here's how you do it. Use a wiring diagram for your car to identify the +5 volt wire, the ground wire and the signal wire for your MAP sensor. Cut the signal wire. Take a 10K (10 kilo ohms, no smaller) cermet or linear taper audio pot from Radioshack (about $2) and attach the ends to ground and signal (the half of the signal wire you just cut that comes off the MAP sensor). Attach the adjustable output of the pot to the other half of the cut signal wire that goes to the ECU. Voila, done.

 

I think the caller is correct in saying that the timing of a FMU setup at 10 psi boost is the same as the AFC hack timing at 10 psi boost. You're in the rightmost column.

However that does not mean you have the correct timing, because you are running the same timing as a NA car at WOT except that you are at full boost .

 

And right up to the point of full boost, the AFC timing is jacked forward. NOT good.

Love the sig, filetofit... you hiring?

 

hmm, maybe that's why I cracked all four top ringlands and one second ring land on my stock pistons, before I created custom MAP hack fuel and timing tables for my PR3 ECU. Too bad that car got stolen.

I am hiring but to qualify you have to have more JB Welds than MIG or TIG welds on your car.

 

The only JB weld on the CRX is to seal the partial weld on the oil return on the oil pan - ran out of wire mid-weld. Everything else is MIG or TIG.

Had my welder stolen, and I'm building the replacement out of transformers scavenged from broken microwaves cause I'm poor white trash... does that count?

 

Correct. Its not the correct timing. Its all wrong for a turbo car. This hack is for people that want low boost on a street driven car. Retarding the ignition with the dist helps..although too far and the car gest really sluggish out of boost.

Never the less the hack is years better then a FMU...

liam

 

You are correct to a point. At WOT at full boost the afc hack and a FMU is going to have the same timing. Its low boost high rpm where the FMU is going to be different. The honda has extreme timing at high rpm and low map signal, and with the afc hack the map pressure is going to be ALOT less then with a FMU. This will cause increased timing. Although from that chart as the map pressure increases the timing will decrease. By keeping the timing somewhat retarded with the dist....you will be fine.

liam

 

is there somewhere we can save this thread in an articles section or something. it is an invaluable resource.

 

Liam: do you think that once i get intercooled, i'll be able to run 8psi with those 310cc injectors (dyno-tuned of course). im pretty sure i can, but having someone falmiliar with the altitude would give me a little more peace of mind.

where in colorado did you live?

 

Modified by Gravy at 9:23 AM 5/25/2004

 

If you don't know how to tune a car, "getting a real ECU" isn't going to help you.

I always hated it when people like you would suggest that spending money is a direct substitute for having half a clue. "Saving for a real ECU" is an oxymoron. If you were at all abreast with current DIY technology or had any real understanding of the subject, you would know that this type of setup can be done for less than the cost of an AFC, and there is nothing hack job about it.

Hell, Uberteg is selling boost code for OBD1 for pennies, and Ghettodyne 1.5 will support boosting on the stock MAP in a few days. What do you mean save up for a real ECU? Last I knew, 95% of Hondata's code was OEM Honda. You mean pay a lot of $ for what you already have?

 

agree with you on that. Props to the innovative individuals that take the time and research to come with much more affordable means.

 

This thread promped me to run the hack. I did for about 6 months, it ran pretty good for what I had. I bought a btm out of fear of 30+ degrees of advanced timing under full boost. By then I had spent enough to buy a hondata so I sold my gear and started over.