Jockobo

i read here that the running the afc with big injectors would cause the ignition timing to be advanced because of the map not reading vacuum....wouldn't it be the same when running the missing link??? doesn't the ecu just go into a set program once you go into WOT and not really care about what the reading off the map is?

extrmeboost

im definitely interested in this topic cuz i just got rid of my missing link.

UberTeg

the timing will get screwed up with the fmu/missing link while in boost cuz the ecu cant see the boost to retard it (anditdoesnt have any maps to reatrd for boost, heh), but not NEARLY as bad as the afc hack. The AFC hack is sooooooo bad with the timing because it TRICKS the ecu into thinking its under more vacuum to cut fuel. The ecu advances timing udner vacuum... so u effectivly advanced your timing. The FMU/missingling uses the msot retarded ignition settings in the ecu during ALL of boost so its a better deal when it comes to timing

HondaCutter

doesn't the BTM kind of solve that problem?

UberTeg

Nope! It comes NOWHERE near solving the problem. The BTM only STARTS to work when you first enter boost. If your timing is already advanced by 10 degrees when u enter boost... you may be detonating b4 the btm even has a chance to act. Even when the BTM starts to work, 1 pis of retard vs 10 degrees of advancement wont do much...

turb

what if i install an ITC together with the afc and 450cc injectors? will it solve the problem with timing?

HondaCutter

what if you're at 10 psi, 1 deg of retard per psi would equal out to 10 degrees of retard which would counteract the 10 degrees of advance...

note:i'm not trying to be a smart *** (in case I come off that way) I'm just interested in this because i plan on doing the afc hack...

UberTeg

The timing would be corect at 11psi... but under that it owuld be advanced. So you could blow up your motor while the turbo is spooling up.

safe driver

you could do what i did and use a MSD digital6+ and statically retard it up to 9 degrees across the board.

VaporTrail

and by the time you buy all those piggy backs, you could have purchased real engine management solutions, not band aids.

safe driver

i know.. but i had the digi6 long before i went turbo. might as well use what i have..

UberTeg

This can do the job yes But it sounds fairly expensive

safe driver

well...

msd digi6 $275 + afc $300 + dsm 450cc $50 = $625
hondata for obd2 vehicles = over $1000
aem ems = over $1000
uberchip = no worky with obd2 vehicles

turb

will an itc solve the problem?

UberTeg

obd1 ecu $100 + converison harness $150 + dsm 450's $50 + uberchip $100 + $20 filetofit afc = $420

Infinity_Racer

so the "chip" eliminates all of that and fixes the timing? how much would you charge to chip my ecu, cus i know i'll mess it up? sorry, i cant really go into your post because my computer is on 56k and has a parapalegic seizures when trying to go into your posts with the big pics

Joseph Davis

450cc DSM $50, Batronix Eprommer 3.2 $75, make your own conversion harness $35-60, busted *** P06 $25 upgrade it to VTEC for a little time and some components, MAP limiter circuit (filetofit or my design, irrelevant) $20 = $230-250

You can ditch the chip burner if you don't care to hassle with having to make your own ignition map and fiddle the fuel, and spend an extra $25 on Uberteg's boost chip. It runs safely rich, and you can tune the mixture a little across the board with the MAP limiter.

Jockobo

i got a friend running 8-9 psi with the afc with the timing set at stock and it havent blown up yet, why's that since the timing is suppose to be so advanced? wouldnt the ecu go into a diff program for timing once u hit wot??? compared to part throttle driving.

turb

ok for the 3rd time..will an itc solve the problem with timing?

The-LS

I was reading the other thread about timing and was wondering just what timing cars running FMU and missing links actually see from the ECU?

after reading this thread https://honda-tech.com/zerothread?id=841443, I just want to make sure I have a solid grasp of what MAP the ECU sees during boost and what modifications people running Missing Links and FMU have their engine actually see.

QUESTION #1) Based on the ignition MAP below, and assuming that is a stock MAP from a stock ECU. When a boosted car hits boost, the missing link blocks off the boost pressure so the ECU sees 0psi correct? This would put the ECU map into the COL 9- COL B10 ignition zones right? So taking a specific RPM of 7000RPM for discussion, after entering BOOST and regardless of boost level 1psi or 23 psi. The car would run ignition timing at 24.25-25.25 degrees since it THINKS its at 0psi WOT right?

QUESTION #2) So for boosted cars, we retard timing at the distributor because of this and SAY STOCK TIMING IS AT 16 degrees, and we retard to 10 degrees BTDC. This would put the same scenario above at the same 7000RPM to an ignition timing of 24.25-25.25 LESS the 6 degrees retard to 18.25-19.25 degrees at whatever boost level at 7000RPM. Is this correct? Am I understanding this right?

Don't tell me to go Hondata or whatever standalone. I'm not looking for a product, I'm looking understanding on how and what is going on during the Missing Link and FMU setups when they are boosting. Thanks

specv5150

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Jockobo &raquo;</TD></TR><TR><TD CLASS="quote">i got a friend running 8-9 psi with the afc with the timing set at stock and it havent blown up yet, why's that since the timing is suppose to be so advanced? wouldnt the ecu go into a diff program for timing once u hit wot??? compared to part throttle driving. </TD></TR></TABLE>

It will probably eventually get there. When I installed my hack there was no problems. Timing was what it was at before turbo. Then it got to the point where my **** was stalling at stop signs and red lights. I was checking all kinds of other crap. Prolly went through 12 spark plugs.... . Ended up being the timing. I adjusted it and it worked great

pngfolife

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Black-LS &raquo;</TD></TR><TR><TD CLASS="quote">I was reading the other thread about timing and was wondering just what timing cars running FMU and missing links actually see from the ECU?

after reading this thread https://honda-tech.com/zerothread?id=841443, I just want to make sure I have a solid grasp of what MAP the ECU sees during boost and what modifications people running Missing Links and FMU have their engine actually see.

QUESTION #1) Based on the ignition MAP below, and assuming that is a stock MAP from a stock ECU. When a boosted car hits boost, the missing link blocks off the boost pressure so the ECU sees 0psi correct? This would put the ECU map into the COL 9- COL B10 ignition zones right? So taking a specific RPM of 7000RPM for discussion, after entering BOOST and regardless of boost level 1psi or 23 psi. The car would run ignition timing at 24.25-25.25 degrees since it THINKS its at 0psi WOT right?

QUESTION #2) So for boosted cars, we retard timing at the distributor because of this and SAY STOCK TIMING IS AT 16 degrees, and we retard to 10 degrees BTDC. This would put the same scenario above at the same 7000RPM to an ignition timing of 24.25-25.25 LESS the 6 degrees retard to 18.25-19.25 degrees at whatever boost level at 7000RPM. Is this correct? Am I understanding this right?

Don't tell me to go Hondata or whatever standalone. I'm not looking for a product, I'm looking understanding on how and what is going on during the Missing Link and FMU setups when they are boosting. Thanks



</TD></TR></TABLE>

I believe this is only true for cars running un modified MAP sensors. Once you start to screw with the MAP signal and offset the pressure curve, the timing get screwy. So for cars with FMUs, the timing should be factory regardless of boost level. In this case, the MSD BTM works decently. The ideal ignition timing curve is not linear yet the BTM can only retard timing in a linear fashion but I believe that most Honda timing curves are quite flat so the BTM gets close enough.

The-LS

any input on this from the morning people... surfing the web when you should be working!

willahlborn

Question #1: Correct.

Question #2: Correct again.

Also, using your diagram of the mBar pressure at -40% SAFC settings, you can see exactly how much your timing would be advanced while in boost by using this device. It would be advanced to about 36-40 degrees.

And I know you're just looking for an understanding of how this works, but... programmable engine management solves all these problems. Buying a BTM or whatever is just putting a band-aid on it, and doesn't really work all that well. By using one of the free or low-cost solutions (Uberdata, Crome, or TurboEdit) you can control fuel delivery while in boost and at the same time specifically control your timing. No more retarding at the dizzy and hoping it doesn't blow up.

Jockobo

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by willahlborn &raquo;</TD></TR><TR><TD CLASS="quote">Question #1: Correct.

Question #2: Correct again.

Also, using your diagram of the mBar pressure at -40% SAFC settings, you can see exactly how much your timing would be advanced while in boost by using this device. It would be advanced to about 36-40 degrees.

And I know you're just looking for an understanding of how this works, but... programmable engine management solves all these problems. Buying a BTM or whatever is just putting a band-aid on it, and doesn't really work all that well. By using one of the free or low-cost solutions (Uberdata, Crome, or TurboEdit) you can control fuel delivery while in boost and at the same time specifically control your timing. No more retarding at the dizzy and hoping it doesn't blow up. </TD></TR></TABLE>

so why would you be at that point in the maps? if the afc is cut out enough just to where the ecu will read around o vacuum wouldnt it use the maps around there?