Refresh old topic for 20V SVT/BT ECU putting SAFC or NEO???

[corolla92levin]

I think this thread is out of the ECU topic larr....

hahahhaha yup.its out of topic ady

 

[wfhan]

err.. anymore updates on this BT ECU matters?
appreciate if someone can post his result and verdict after installing
any SAFCs, e-manage, etc piggyback ecu on BT..
is the myth busted?

 

[GSRTurbo]

any updates

 

[Mivec]

So who can really confirm on the BT using SAFC or Emanage is good? if got Dyno Chart is good to confirm on this.... :emoticon_U:

 

[20vturbo]

my mech is using safc neo in his bt rwd turbo..seems working fine for him..

 

[netmatrix]

no sale bump

 

[20v_ke35]

so any one try their BT with AFC NEO? Care to tell....

 

[katopunk]

i ain't so sure. but i'm one of the BT user running with safc2. i've talked to cuscostrutbrace on the pm. he quoted:

Hi,actually i run SAFC with SVT.If you tune it well,it will improve performance a bit.Some people say SVT can relearn the a/f mixture so i disconnect the O2 sensor from the beginning i installed the SAFC,so i did not know how it will work with the O2 sensor connected.

I have read in the net that the ecu will trim the a/f over time.As far as i know,the trim will be done during closed loop only,not when open loop (full throttle),so your SAFC should work when youre full throttle but not during cruising or idle.But it is just my theory.

in my case, i went for dyno and safc tuning. i do notice that the safc indeed will increase the hp. my car was increased about 4-5hp.

my tuner set lean mixture for low throttle. but then my fuel consumption is still the same even i cruise and low throttle.

so i guess. like cuscostrutbrace said. safc will only work during open loop. it will not work during close loop because the stock ecu will override the afr.

 

[katopunk]

and this is what i found on the internet. Toyota Levin/Trueno ae111 Coupe info [Archive] - RacersHaven

richardAE111
05-04-2007, 01:22 AM
I have a SAFC2 in my car how could i tell if its been ignored by the ECU?

The only way is to compare A/F ratio readings from when it was tuned and after some driving. The guy I mentioned earlier had actaully had his car on the dyno, tuned the SAFC and after three runs on the dyno the ECU had reverted back to stock functionality. He was using the SAFC to lean out the mixture after some intake and exhaust modifications and did so, but after three runs on the dyno it was back to running rich. I have also seen a similar situation happening with a SAFC and a EP91 Starlet.

To elaborate a little on the SAFC issue. The reason why it's ignored is directly related to how the ECU is programmed. In Toyota ECU's the fuel and ignition tables are directly tied together and are not separate as is the case in ECU's from other manufacturers such as Honda, Nissan, Mitsubishi etc. This makes Toyota ECUs hard/expensive to program and the reason why piggyback fuel computers do not function effectively.

The initial settings may work but soon after, the various triggers and countermeasures built in to the ECU will ignore the attempts to alter the MAP sensor signal and return to base maps. What I would do if I was in your position is get a A/F ratio reading directly after a tune and then go for a drive/dyno run and get it checked again. I hate to say it but I'll put money on it that the readings will be different.

Let us know how you get on if you do so.

05-04-2007, 01:02 PM
Good to see you're thinking about it Conor but this is where the differences in the various systems lie. As you may have read above, I mentioned that the E-Manage with injector and ignition harnesses does not have this problem and the same applies to the OER controller and harnesses. However, if you use the E-Manage without the harnesses you will have the difficulty of the stock ECU reverting back to stock functionality, the exact same difficulty you'll have with a SAFC. I have also read about this happening with a E-Manage without harnesses to an AE111.

When you use a piggyback management system with harnesses, it doesn't take its reading from the sensors before the ECU. The ECU works like it normally would, however, the E-Manage takes signal readings from the ECU then makes its own decisions; unlike the SAFC. It alters the signal before the ECU therefore leaving the ECU to do what it likes with the readings, and as I've said, Toyota ECU's don't like to be messed with, they know something is not right and will adjust to the base map to compensate for the erroneous readings.

Also just to make you aware, the SAFC seems to work very well on Honda and Nissan cars, with some Mitsubishi's also, but I have heard of a situation where a SAFC did not function corrrectly on a Evo VII. According to what I read, the Evo VII has roughly 30 fuel maps built in to the stock ECU, but the SAFC only can alter values for 2-3 maps, it simply does not have the processing power to alter them all, so the majority of the time, the SAFC on the Evo was completely useless. This also seems to be the case on the newer model Subaru's. They seem to function exactly like a Toyota ECU.

The way it happens is as follows; as I mentioned earlier the fuel and ignition tables are directly tied together and are not separate as is the case in ECU's from other manufacturers. When a SAFC is used to lean out a fuel curve on a Toyota ECU, it tells the ECU that there is less load on the engine (via changing the MAP sensor signal to a lower value). Less load to a Toyota ECU means that it advances timing. It will advance the timing until knock is detected, it will then retard and repeat, after this happen a certain number of times, the ECU will simply ignore the signals from the repeated timing advances. Timing has three states as defined by your knock sensor: advance, hold, and retard. The car will always try to hit the preset value, but will hold at a certain knock level, or begin to retard if the hold level is passed. The car however, can learn from the volatile memory the peaks for the car and may opt never to pass that level (unless reset) after a certain amount of attempts are made; or it will make a attempt at the preset peak each time, or then jump back to the recorded peak instead of just retarding back sequentially. Very clever ECU, yes, that's exactly what I was thinking... :)

So to sum up, the difference between a MAP sensor altering computer and a fuel computer with harnesses is that the harness attached computer will do the programming after the ECU, and the SAFC-style computer will do the programming before the ECU. In essence they are both "piggyback" computers but the distinction between the various types has to be made.

 

[tctho]

Anybody heard about the Apexi Power FC? Any comment?

 

[nappx]

b.u.m.p

others electronic device can work with 20V..
don't say standalone arr..