Re:The truth about the afc hack!!!!!!!
 

Can anyone say something about using the Apexi ITC to fix this problem? can you?

Re:The truth about the afc hack!!!!!!!
 

No. The ecu will not compensate for any more fuel even at say 2 psi. Not only that, but the stock injectors are not capable of supplying enough fuel. You will need some sort of fuel management. It could be a cheesy FMU, pump, and some larger injectors or it could be a Hondata or Uberchip. There are plenty of options. I chose the AFC hack because it was cheap and easy.
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Re:The truth about the afc hack!!!!!!!
 

OK so if I decide to go with the AFC hack and take all precations like using 91 fuel, one level colder plugs, good sized intercooler and listen for detonation, I should be fine right? this is for 6-8psi on a D16Y7. What about using slightly smaller injectors like 350cc-400cc so that you don't have to go so far negative on the AFC? Will this work up to 7psi? will this work in getting closer to where the timing should be?

Re:The truth about the afc hack!!!!!!!
 

Yes you should be fine.

No, do not use smaller injectors. If you use smaller injectors the settings on the AFC will be higher, thus making the hack not work. Lets say with 450cc injectors you set the AFc at -40 all the way across. This will trick the ecu when you are boosting to think that everything is ok and not to send a cel. If you use say 350cc injectors, the settings on the AFC will be around -30 or lower all the way across. This will probably not be enough to trick the computer. Get a set ofd 450cc DSM injectors and you will be fine. Also, I would run 8 psi instead of 6. At 5-6 psi the AFC is advancing the timing to the full extent. 8 psi will be allot better.
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Re:The truth about the afc hack!!!!!!!
 

OK thanks, but to get to 8psi you must first pass 6 psi. and there is gonna be time spent at 6psi....what about that?

Re:The truth about the afc hack!!!!!!!
 

My car sees 6 psi for about a milisecond. Its like its not even there. As long as 6 psi is not your max boost.
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Re:The truth about the afc hack!!!!!!!
 

true true....so if you ever want boost you have to go full throttle? no partial throttle cruising at 4-6 psi like when you use boost to go up a hill instead of downshifting. seems like those milleseconds of detonation would add up....but I was reading the other day that detonation is almost twice as likely to happen at low-mid RPM because at high RPM detonation doesn't have time to do it's bad stuff.

Re:The truth about the afc hack!!!!!!!
 

I have never been in that situation. We don't have any big hills around here. I have ran at about 1-3 psi sometimes just kinda cruising, but if I need any more power I just stomp on it. I'm not easy on my car. I either drive good or bad. Mostly bad. I can't detect any detonation anywhere. I'll check under a smooth low throttle run and see If I can hear anything. I doubt it. ???
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Re:The truth about the afc hack!!!!!!!
 

This is my set-up:
http://www.geocities.com/thermalfid16/VAFChack1.html

boosting 8psi and still at stock timing, no detonation. I do want to retard my timing a little bit. Any suggestion how far.....Dr Boost? I was told around .5 per 1 psi boost.

Re:The truth about the afc hack!!!!!!!
 

even with the hack Im still having trouble getting my car to idle. What could be the problem??

Re:The truth about the afc hack!!!!!!!
 

So what happens before your car actually hits boost? Like while the turbo is spooling, is it ok to run with the timing retarded like that?

Re:The truth about the afc hack!!!!!!!
 

aids333, I had the same problem in the beginning. You need to fuk with the AFC some. I started out -40% all across. My idle was erratic. I adjusted it to -38% on the low side. This is my set-up, D16Y8 @ 8psi, DSM 450cc (honda resistor box), no timing retard, stock pump, stock FPR with VTEC set at 5500 RPM:
-1000-4000 RPM= -38%
-4000-5500 RPM= -36%
-5500-6500 RPM= -35%
-6500 and up= -34%

No diling problem whatsoever. It idles like stock! No dyno yet tho ;D

Re:The truth about the afc hack!!!!!!!
 

I had my injectors down at -40 area at idle, and it was messing up really bad. I am using the 10 watt 10 ohm resistors, not a resitor box, do you think that could be the problem? I have a z6 running 7-9 psi. What spark plugs is everyone using?? Are you getting any pinging with stock timing?

Re:The truth about the afc hack!!!!!!!
 

no pinging @ stock timing @ 8psi. I'm using NGK 7 series, gapped in stock.

Re:The truth about the afc hack!!!!!!!
 

alright I got the idle to work, I put the timing near the middle, I figured that was stock. How can I check? I also had a vacuum tube running from my TB to my map sensor (just left over stuff from the check valves) Bad idea..I have the fuel set at -38 to -35 across the board. It runs so smooth, but now for some reason Im only getting 5 lbs of boost... I dont know what that is about, its probably something not related at all, but when i figure that out Ill let you know. Thanks for the help.

Re:The truth about the afc hack!!!!!!!
 

just an update on my setup, i think everyone is kinda making a big deal on the fact that the afc advances timeing but no one has exact numbers. currectly using the afc im boosting 10psi with boost creep going to 11psi with STOCK timing at the distributor. i was retarding it at the dist when i first started using the hack, but there seems to be no need for it. ive also used the ghettodyne v2.2.1 and well that didnt last in my car more than 15min before i went back the afc.it has those bumps at vacum and felt slower. the AFC WORKS and is smooth!! d16a6 /t3/ customcoach ic/450ccinjectors/walbro intank pump with 208,000 miles! lates!

Re:The truth about the afc hack!!!!!!!
 

I was getting detonation at stock timing. ??? Otherwise I would have kept it there. I'm going to set it back to stock when I get my ecu back from Joseph.
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Re:The truth about the afc hack!!!!!!!
 

I can't believe this topic.....sits dead for months, then this sudden revival.

Re:The truth about the afc hack!!!!!!!
 

i just read through this entire thread and there is some really good stuff here. some very knowledgable people. quick question. i was wondering whether the vafc adjusts the voltage between the map and the ecu in accordance with rpm AND boost or just rpm. i mean, with this setup, will the injectors be pulsed the same at say 5000 rpm/vacuum and 5000 rpm/8psi or does the vafc compensate and vary the voltage with the change in pressure? i've been told its only rpm dependent, but it seems like this would run REALLY rich in low throttle/vacuum. also, is the smc the same/as good as the vafc? i'm cheap. thanks

Re:The truth about the afc hack!!!!!!!
 

it varies it just by rpm. smc ive heard is just as good but a little more difficult to tune, and you dont get the fancy display.

Re:The truth about the afc hack!!!!!!!
 

It only works off rpm, but the timing would be changed by vac/boost. This is the bad part. IMO the AFC is more accurate than the SMC, but I'm sure it works just as well.
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Re:The truth about the afc hack!!!!!!!
 

thanks. i'm still confused though. how would a car using a vafc be able to cruise on the highway (without shooting fuel out the exhaust) if it is getting the same amount of fuel under vacuum as it would under boost at a given rpm? i mean technically it should get almost twice as much fuel under pressure (10-11psi) as it would under vacuum, maybe more. i thought jdavis said something about the vafc stretching the map signal so it is boost and rpm dependent (normally 3v is atmospheric; with vafc 3v can be disguised as vacuum to pulse the bigger injectors slower and 5v can be disguised as atmposheric to open the injectors more under boost). if its already altering the voltage going to the ecu from the map sensor, why couldn't it be analogous to pressure changes!?!?! am i missing something?! i would like to try the hack (using fmu now) but not if its going to kill my mpg on the highway! sorry for the long post

Re:The truth about the afc hack!!!!!!!
 

thanks for knowledge

Re:The truth about the afc hack!!!!!!!
 

The AFC has high throttle/low throttle settings. If you are at full throttle you would be running on a different fuel map(RPM dependent still). The AFC isn't exactly acurate no matter what you do. It is just a hack.

Nope.


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Re:The truth about the afc hack!!!!!!!
 

will a second MAP sensor connected to the throttle input help?

just like the one described here: http://www.alltrac.net/mods/boostedSAFC.html

and:
(What is the "MAP sensor mod"?)
http://members.shaw.ca/costall/1000Q/answers-SAFC.htm

Re:The truth about the afc hack!!!!!!!
 

i was reading earlier and read that someone said the afc hack isnt good if you are running under 8 lbs. of boost because it advances ur timing to much. I was planning on gettting 450's and a vafc and maybe retarding my timing a little but what do yall think should I just go with another whole fuel managemnt system if im not gonnna be boosting 8 lbs. or more. I was planning like 5-7 lbs of boost for now and maybe bump it up to 7-8 later. My engine is a z6 and my turbo is a TCO5-12 intercooled. What setup do yall think I should run for my fuel management. And the last thing I wanna do is blow my engine! Thanks for the help!

Re:The truth about the afc hack!!!!!!!
 

i dont know who comes up with this stuff mang. take it form a guy that has used the afc in low boost and higher boost(12psi). it doesnt advance yout timing, not so much that it will cause detonation. im currenty runing 10 psi on stock timing. thats how well it works. if ;you do experience detonation, add more fuel with the afc and bam problem solved.(thanks 91accordlx for the tip) AFC! AFC! AFC! Using the afc and 450cc injectors maybe a new fuel pump and youll be set. the afc really is not complicated at all.

Re:The truth about the afc hack!!!!!!!
 

I don't know how you are getting away with stock timing with no detonation. The AFC does advance the timing a rediculous amount. Also, adding too much fuel will cause detonation.

The reason people say the AFC isn't good for 5-6 psi is because of the timing that it reaches at that point in the map. The ECU is advancing the timing the most at that point. If you can get away with it using stock timing than I guess you are just lucky.
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Re:The truth about the afc hack!!!!!!!
 

well i dont know about that. you say that the afc advances timing, do you have any dyno info or real numbers to prove this? last i remember runing lean caused detonation not runing rich. preignition causes detonation. just want to get the facts straing mang.

Re:The truth about the afc hack!!!!!!!
 

Well how can you preignite without fuel?

I don't have to prove anything. I can go out to my car, start it up and realize the AFC is advancing my timing. Do you have any dyno numbers or anything that proves me wrong?

Why don't you try data logging your ecu and take a look at the timing maps. Then, disconnect the AFC and have a look at the timing maps.
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Re:The truth about the afc hack!!!!!!!
 

yes you need fuel duh, but runing rich doesnt necesarily cause detonation. as far as the timing maps go, do that for me and prove me wrong. ;D im not here to argue with you. im just want to let people know that they dont have to worry about timing when their only boosting 6-7psi. the afc does its job and it does it well.

Re:The truth about the afc hack!!!!!!!
 

I have a delsol with a b18c1 and a super 60 T3 using the vafc. I have been told yes and no about running 5-6 psi. I know that the c1's have high comp and i dont want to detonate my motor. I was planing on turning the timing back a few degrees. Will that be ok? How much boost can i run on a gsr motor w/stock internals using a dsm's and a Vafc?
Thanks
Steve

Re:The truth about the afc hack!!!!!!!
 

I hve been running stock timing ever since I had my hack set-up. I started at 6 psi boost with no problems. It felt so good that I increased it to 10 psi at one point. It worked with no MIL. 10 psi kind of scared me. I'm back to 8 psi with no problems except a stupid code13 (barometric pressure) every now and then. It does not affect the performance tho, even with that code. I've talked to a lot of people about the hack. It seemed like most people with OBD2 suffers from this code 13 sometimes.

Re:The truth about the afc hack!!!!!!!
 

10psi is fun! ;D

Re:The truth about the afc hack!!!!!!!
 

Things that will keep things safer using the AFC hack:
-INTERCOOLER
-Properly gapped stock plugs or one step colder
-High quality gas
-properly sized turbo
-retard timing all the way, then gradually advance it back to stock or as far as you can go without hearing detonation
-WIDEBAND 02 sensor, not that autometer crap
-start off rich then lean it out till it runs well, keeping an eye on the wideband and not going past 12.5/1 a/f ratio
- Know your car, drive with the radio off and no one else in the car when tuning
- spend enough time tuning and don't get crazy with the boost ( past 10psi on your average turbo, this doesn't mean you can run 10psi on a T4)
-Don't be at full boost more than 15 seconds
- make sure your car is up to par before adding a turbo (all maintenance)
- check that your cooling system is ready for the extra heat
- Give a thumbs up to the GT you just blew by and don't flash your hazards when you fly by that cobra after the race is already over.

Re:The truth about the afc hack!!!!!!!
 

Thanks a million for saying have the right sized turbo for engine. I have a f22a and I was rolling a mitsu tdo4 and I had a lot of detonation at full throttle when it hit around 6 psi then it would go away when I hit 10 psi. Then when I put the tdo5 (14b) in the detonation was totally gone and I didnt have a detonation problem again. You definetly have to get the right turbo for your engine. In the world of turbos SIZE DOES MATTER!!!

Re:The truth about the afc hack!!!!!!!
 

When you understand that Honda maps are in MAP by RPM format for the range of ~300 mBar to ~1000 mBar, and then take those stock NA maps and stretch them via a MAP voltage cut to cover ~300 mBar to 1600+ mBar, well, ---- has a strange way of getting fucked. Most people pick stuff like this up better visually, so try graphing it out on paper.... or look at Ghettodyne 2.2 NA versus Ghettodyne 2.2 Boost maps; envision the NA headings on the Boost column headings (that's what I did with Ghettodyne 1.01 for the PM6 MAPhack basemap - original PR4 MAPhack was all done by hand calculation with a hex editor).

You want real numbers? PGMFI.org is covered up with them... if you notice my link to the MAPhack thread on PGMFI, none of the people who know wtf is going on with speed density EFI contradicted me. I don't mean to shove that in your face in a rude manner, but if you went all the way through this thread without forming a tenative grasp of the subject then you need to be given good reason to rethink your current stance.

Preignition != detonation. Preignition is caused by a hot spot in the combustion chamber which ignites the AF mixture, which results in "detonation" when the preignited flame front smacks into the spark plug ignited flame front. Actual detonation is caused by too much heat, charge density, and/or TDC dwell time for a given setup. The knock threshold of the fuel is exceeded by combustion chamber conditions causing it to explode instead of burn.

Re:The truth about the afc hack!!!!!!!
 

I don't know if this was already mentioned in this thread or not. But another problem with the Hondas and boost is simply that unless your routing your blow off air back into the charge piping before the turbo, youre MAP sensor has told the ECU to expect X amount of pressure in front of the T-body but this pressure is suddenly gone.

Anyone else have those really f*d up idles where the meter bounces around? Well hey this is most likely your culprit.

Its true that proper tuning can prevent this, and any ECU thats designed to know that when you hit vacuum in the engine after going into boost, can ignore the old MAP reading.

Anyways, this is just an idea of what may be causing those erratic idles and another reason why the AFC hack isn't the best way to go necessarily.

Re:The truth about the afc hack!!!!!!!
 

I, also, am curious about running the MAP sensor into the TPS port on the s-afc. Sounds like a better way of tuning. Has anyone attempted this and what results did you find?

;D

Re:The truth about the afc hack!!!!!!!
 

can i ask why?...do u mean it only WHILE you are tuning or under any condition?