ERIC-TC

This is a tuning tip for folks w/ Wide-Bands that can programm their e-manage blue or ultimate.

If you do not have a wide-band and if you cannot programm your piggy-back this mod will not work for you. This will allow folks who do their own fuel maps to get full and total control of fuel with just a piggy-back fuel computer (No stand alone required).

The tC has a fuel contol mode called OP3 (Open-Loop 3). This is basically an extension of open loop 2 which typically but not always starts somewhere around 3500 RPM . OP3 extends open-loop into the lower RPM range 600 RPM's or as low as your car can idle. There is also OP1 this is what the tC defaults to when you first start the car it runs for a few minutes until the primary wideband warms up. Then the car would naturally switch over to closed-loop and idle from 14.7-15.3 A/F ratio.

Closed loop on the tC is a big pain in the ___, because no matter what you do it will always adjust the injector duty cycle until the A/F is at close to stoichiometric 14.7 no matterf you have 370cc injectors or 550cc injectors. This is a major pain in the rear because if the ECU is messing with the fuel trims under 3500 for most of the time, then tuning the emanage under 3500 or in-between the ever fussy line of closed-loop / open-loop becomes very difficult. You'll go from lean to rich too fast and mess up your power during the transition to open-loop.

Even if you tune with the greddy pressure sensor it will not be right on cause boost pressure does not equate to open-loop / closed-loop. what my modification allows you to do is to force the tC to use the open loop protocol (the same parameters it's using to calculate fuel flow at higher, more demandind times like full-throttle knuckle-busting runs) all the time...The ECU will not engage closed-loop at all...ever

Take some notes:

1. The car starts at open-loop.
2. The car goes to open-loop when you go past 3500 RPM (usually).
3, Large throttle changes also bring on open-loop
3. When you are pegging the needle the system is in open-loop.

The tC's ECU system is only in closed-loop when the car is trying to lower emissions and/or save gas. Once the tC is "forced" into open-loop all the time, tuning the emanage is very straight-forward and extremely repetable.

How do you get the ECU to stay in open-loop 3 all the time? You unplug the primary-oxygen sensor harness. That's it.

The car does not go into safe-mode or any other limp mode. The knock sensor still works, the ECU still pulls timing. The car still hauls ___ and the max RPM is still just north of 6000 RPM's.

The bad news? You got to have a wideband so you can adjust the injector sizing to get the car to idle at a perfect 14.7 when the engine is fully warmed up (while in park).

I found that if I played with the injector sizing setting on e-manage I could get the car to idle at whatever A/F I wanted and it was fairly consistent +/- .5 on my wide-band.

Tips to getting the perfect fuel map:

Remove all airflow correction (they will not be needed, initially). Only add injector duty when needed under boost to hit your target A/F. I found injector correction was not needed at higher RPM's. Actually a small airflow correction (reduce MAF signal) could me made at WOT -but I left the car a little rich to be safe.

After road-tunning the car richened up at any and all throttle settings at any boost level exactly like my fuel map told it to. partial throttle A/F was a whole lot better.

The only thing is that you will not be at a perfect 14.7:1-15.3:1 most of the time. I found I was in the upper 13's on the high-way and 14.3 in the traffic jams. Cold, hot dry or rainy the A/F did not fluctuate much it was close to 14 most of the time while off boost. I'm sure that MPG will suffer a little from the mod -but some gas money is cheaper than a new engine...and no more figting the ECU for closed-loop control!

This mod will give you a CEL it will read heater circuit oxygen sensor

1. You should not run the factory wide-band sensor with the heater circuit off long term. You probably can take it off -reinstall to get the car inspected. I'm sure that the A/F signal could be by-passed with a switch or other device to allow closed-loop to be turned on and off. from the cabin and keep the heater on like stock.

Since the wide-band A/F on the tC is current based and not voltage based you have to use gold-plated contacts on switches and/or relays that are used to hack into the factory A/F signal.

You could still use the mod to cut the time needed to programm your emanage fuel maps by keeping the ecu in open-loop. After you are done then reconnect the wide-band and the car will switch over to closed-loop mode again.

Happy Boosting

BOXMAN

Damn Eric you are the MAN!!!!

ProshopXB

I was thinking the same thing.. Bravo Eric..

krdshrk

Seconded

Good info!

satoman44

so, even with this new tip, dezods black box is still a good thing right? since it will adjust fuel according to boost pressure so you can have good mileage when driving normal? if so, this is still a good tip to tune e-manage. good job!

mike6789k

no, this blows the black box out of the waters!!!

quick someone figure out how to get this to work without throwing a CEL!!!

satoman44

ya but gas mileage will suffer and i really enjoy having a boosted car that gets me 27 mpg. and ya, the CEL is another reason.

mike6789k

if the black box lowers your afrs (which it does...) you will also get lower gas mileage

satoman44

only when u build boost. your in vac during normal driving and on the highway, which is where this tuning method has its negative. like eric said, he was running an AFR in the 13's on the highway. with the black box, u can still get your 14.7...

for me, i want the black box for insurance when i have the urge to make a spirited run, but not all the way WOT. ie, for building boost when not flooring it, maybe half throttle or sumthing like that.

mike6789k

i see...

mike6789k

so the black box, is it plug and play? or do we need to tune it aswell?

satoman44

u can get it with a pretune, however, i think you need to wire it in. it might be easier if you already have the pnp harness and it also needs a vac source.

but yes, this tune method seems like it can help tune your WOT e-manage map.

ERIC-TC

The black box is better because the ECU will actually control down to the A/F that you want (but only when you are under boost). With the black box The tC ECU will actually work for you as opposed to against you and your MPG will be untouched when you are not under boost. Plus, No CEL's and no failed emission test.

With the black box the A/F correction is already pre-programmed as a funtion of RPM and boost (If you purchase it that way).

I should be getting my black box at the beginning of Dec after the group buy is over. I will then work with this other tool. I think it's going to be the final tool that will allow my tC to operate like a factory turbo car. That will be the day that I say "I'm Done" then I'll look at other stuff to screw up on my car

Garage1217

iTrader: (5)

Very interesting post Thanks for sharing.

mike6789k

haha awesome... so the tune that comes with the box, is it only for dezod kits? or can i use it for my greddy kit?

OuterHeaven

Very informative... This will definitely come in handy. Just a reminder that your o2 sensor can become clogged if you leave it in the o2 bung disconnected. That is an expensive sensor and really should be treated well. Now all we need to know are the threads for a small bolt to plug it up when not in use.

XD40tC

A plug wouldnt be at all hard to find.

soros151

I'm getting it and I'm N/A. So that can answer your question.

toyotaracer9

hey eric-tc what would happen if I tried this without fuel management ?


for the plug u can go to an autoparts store and ask for an oil drain plug that is M18 X 1.5 .

318_tC

what wideband works for this? I know AEM Uego doesnt.