<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by J. Davis &raquo;</TD></TR><TR><TD CLASS="quote">
I did before there was a Ghettodyne... by hand, in hex. Old Skool, y0.</TD></TR></TABLE>

On a commodore 64 right?

 

Quote, originally posted by Mad Chemist »
So the best way to hack it is with full boost instead of 6 psi @ 7k with advance of 39 degrees?


I am interested also... although I am only -28 on afc at idle with my 450's (not -40).

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by X2BOARD &raquo;</TD></TR><TR><TD CLASS="quote">J.Davis... how come you were able to alter timing with the obd0 bin and not fuel ?</TD></TR></TABLE>

The AFC hack takes care of fooling the ECU into boost, and more or less tuning the fuel. My modifications to the ignition map were to bypass the ignition problem, and to provide ignition retard when used in combination with the AFC hack.

But as far as tuning fuel maps, I got partway through tuning an LS fuel map on the above AFC hack/MAPhack setup, was running between -40% and -38% across the board on the AFC... always planned to be able to set it at -40% and then sell the AFC and run a voltage regulator hack on the MAP sensor - send in a precisely regulated 3 volt input to the MAP sensor instead of the stock 5 volt signal would be the same as -40% AFC cut.

 

thank you joseph for doing this. I know you and I both hae explained this about 20 times each, probably more for you. Hopefully the afc hack lovers will STFU.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by J. Davis &raquo;</TD></TR><TR><TD CLASS="quote">The AFC hack takes care of fooling the ECU into boost, and more or less tuning the fuel. My modifications to the ignition map were to bypass the ignition problem, and to provide ignition retard when used in combination with the AFC hack.</TD></TR></TABLE>

I guess I still don't quite understand the freeware programs... I thought you would be able to control the fuel via the ecu making the afc redundant.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by J. Davis &raquo;</TD></TR><TR><TD CLASS="quote">...set it at -40% and then sell the AFC and run a voltage regulator hack on the MAP sensor - send in a precisely regulated 3 volt input to the MAP sensor instead of the stock 5 volt signal would be the same as -40% AFC cut. </TD></TR></TABLE>

It's not an eng. mgt system , but that sounds f**kin' bad ***....

X2 (Excuse my language)

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by X2BOARD &raquo;</TD></TR><TR><TD CLASS="quote">

I guess I still don't quite understand the freeware programs... I thought you would be able to control the fuel via the ecu making the afc redundant. </TD></TR></TABLE>

The setup I'm discussing was before there was any freeware Honda boost code. I was using a hex editor, a c64, and my own noggin to do this at first... then the early Ghettodyne tuner (pictured above here on the second page of this thread) came along. While it was not at that time boost-capable, it made tuning fuel and ignition maps in conjunction with the AFC hack a whole lot easier. You have to pretend my last post or two in re MAPhacks as if I were talking about 1985 era technology in a reminiscent tone.

In this day and age, I do advocate the freeware boost code over an AFC hack, because it is not only better, it is also cheaper. And don't apologise for your language, I swear all the ******* time.

 

Thanks for the explaination J.D....

But you're such a ******* potty mouth....

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by J. Davis &raquo;</TD></TR><TR><TD CLASS="quote">
Now, heaven forfend you should have paid me a lick of attention when I advised people that running as much boost as the stock Honda MAP sensor is capable of reading is your route to safety with the AFC hack. Note how you end up within a degree or so of your otherwise normal ignition timing when you transition into boost. You can't help the transitory high ignition advance you pass through, but with how quickly turbos spool in most cases it doesn't matter; you spend the bulk of your time during the boost event at full boost, and if you have retarded your distributor 2-3 degrees you should have adequate ignition retard under boost.
</TD></TR></TABLE>

Sorry for asking the same question over again, but I'm slow (at least I can admit it and try to learn ).
However, given that my setup is as follows: B20 @ 6psi, running AFC Hack and 2 degrees retard at the distributer. You're saying that I can adequately run higher boost and that it's possibly more beneficial to do so?
Thanks in advance and to you for spreading some knowledge.

 

Yup, just beware the B20 cylinder walls... you hear a lot about them being weak, but you never hear much from turbo B20 people, so that might be mostly internet myth. I know JalopySiR got 200 whp off of 6 psi on an AFC hack with a MAPhack chipped ECU, we were both surprised it did so well. THe fuel maps were the wierdest ever - I pulled 15% fuel from the stock LS ones past 4500 rpms. Makes no sense, worked like a charm.

 

Hey J
Also on pr3 do u know how to remove the speed limiter?
Is there anyway you could burn me the maphack program (i dont have a burner)

Of coarse ill pay you

 

can anyone answer my question (its up twords the top of the page a lil more) i am very curious.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hatchback_al &raquo;</TD></TR><TR><TD CLASS="quote">Ok, so i am running a pr4 ecu in my car right now (91 dx hatch y8 swap) and i have it socketed for eproms. ive been wanting to jump on this turboedit or ghettodyne deal for a while, but i have no clue how to use it. i read your stuff and still ahve a hard time. i understand the ignition gets way too advanced using the hack at -40% right, bad deal. so, can i use the vafc to control my vtec and fuel and have say stock p28 fuel and ignition maps in my ecu, but have the ignition maps tinkered with to retard under the boost a little. would using the program in teh ecu keep the vafc from advancing the timing? or is that not possible when you use the vafc?</TD></TR></TABLE>

Yeah thats the map hack j davis and me were talking about, use the vfac to limit the map signal and retard the timing to prevent be at like 4 psi and 39 degrees advance

 

hey j davis, im down with tha ecu chipping (i can respond with a pm because im a trial user)

 

the bucking is caused by

1) too little ign advance
2) too much fuel

with the hack it's usually too little ign advance in the midrange b/c ppl retard at the dizzy.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by J. Davis &raquo;</TD></TR><TR><TD CLASS="quote">Yup, just beware the B20 cylinder walls... you hear a lot about them being weak, but you never hear much from turbo B20 people, so that might be mostly internet myth. I know JalopySiR got 200 whp off of 6 psi on an AFC hack with a MAPhack chipped ECU, we were both surprised it did so well. THe fuel maps were the wierdest ever - I pulled 15% fuel from the stock LS ones past 4500 rpms. Makes no sense, worked like a charm.</TD></TR></TABLE>


buddy was running a b20 turbo. A spun rod bearing killed his B20 last week. He was running a b16 vtec head with a T-78 turbo (single turbo upgrade for supras).

 

Yeah, i set my ign at -6 and -2 (degrees retard).

The -2 hauls *** and has GREAT throttle response. -6 was laggy as hell and didn't pull nearly as hard.

I never realized that the more you boost, the safer you are..... until I saw that map (in terms of timing). THat's really interesting


Thanks for the info! Great job explaining it.

 

Blake Warner/Uberteg stated that the bucking on OBD1 cars is injector cut due to the AFC hack causing what the ECU percieves as a high vaccum engine decel situation. I believe him.

I'll repeat again, I'm not a big fan of the AFC hack, but if you know the risks and can tune around them it does the job.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by J. Davis &raquo;</TD></TR><TR><TD CLASS="quote">Blake Warner/Uberteg stated that the bucking on OBD1 cars is injector cut due to the AFC hack causing what the ECU percieves as a high vaccum engine decel situation. I believe him.

I'll repeat again, I'm not a big fan of the AFC hack, but if you know the risks and can tune around them it does the job. </TD></TR></TABLE>

AKA- he says it's cutting the fuel b/c the car thinks it's coasting. I still like my theory better, hehe

 

Just to expand... doesn't that fuel/injector power cut on deceleration only occur on B series ecu's ?

Also, I thought it was engaged via rpm signal, not map....

 

My d16 reads "AIR" on the WBo2 when I let off the gas so yup D series do it too. How could decel injector cut be RPM based? Decelaration can occur anywhere in the RPM range.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by X2BOARD &raquo;</TD></TR><TR><TD CLASS="quote">Just to expand... doesn't that fuel/injector power cut on deceleration only occur on B series ecu's ?</TD></TR></TABLE>

B-series ECUs and D-series ECUs are the same hardware, run the same code, are effectively the same thing tweaked for different engines. However, most all OEMs have an injector cut on decel, SD or MAF.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">Also, I thought it was engaged via rpm signal, not map.... </TD></TR></TABLE>

The only time map signal reads vacuum higher than idle is on engine decel or coasting in gear, and since there is no load in those situations there is no need for fuel and the ECU cuts them off.

 

j davis for mod 2k4

 

You'd make a better mod than I would, Sam.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by X2BOARD &raquo;</TD></TR><TR><TD CLASS="quote">Also, I thought it was engaged via rpm signal, not map.... </TD></TR></TABLE>

Note that decel is engaged when more than one circumstance is met; as suggested by other here, one of those circumstances is vacuum. In order for the ECU to initiate decel, the engine speed also needs to be above some amount, probably in the mid 1000's.

 

Okay I'm slow and it took me a while to get it, but let me know if I have it summed up right:

-run 10-11 psi on the VAFC and DSM 450's with a timing retard of 3 degrees at the distributor and I should be good to go, safety/reliability-wise? I know about the OBD-I clips and resistor box I'll need, I'm just talking about the tuning side. I read through that AFC hack thread, and it helped sorta but this thread kicks ***.

Let me know if I'm understanding properly.