The "let's brainstorm how to make a piggyback work" thread

[eTiMaGo]

Right, I see what you mean, that could most certainly work too, gonna look more into that

And that's a very sobering fact about the Miata ECU, I would never have guessed!

[Nexus1155]

http://www.allproducts.com/manufactu...911154234.html

probably can score that for pretty cheap if you contact them. I was introduced to the Wideband output signals from a friend a while ago, he said Zeitronix also has them on their kit just to offer an alternative to the LC1.

The SMT8 should work as well as long as it has the programmable outputs as well, this piggyback was also recommended to me by the same person who told me the AFR Gauge trick. The SMT6 that they discountinued can be found for around $150-$200
In theory it should honestly work if the ecu doesn't freak

[eTiMaGo]

Originally Posted by PK198105

i can almost guarantee a CEL, since the ECU is programmed with safety margins and thresholds.

Yes, but, what I mean is, if you want to run a richer than stoich ratio without the ECU freaking out, you need to fool it into receiving "normal" signals.

Say that at stoich (14.7:1 AFR) the O2 sensor has a voltage of 2.5V Your target AFR is, let's say, 12:1, which would (I'm guessing) correspond to a voltage of 3.5V from the sensor. The trick would thus be to change this 3.5V to 2.5V so the ECU thinks the catalytic system is working just fine and there's no problem.

Originally Posted by Nexus1155

http://www.allproducts.com/manufactu...911154234.html

probably can score that for pretty cheap if you contact them. I was introduced to the Wideband output signals from a friend a while ago, he said Zeitronix also has them on their kit just to offer an alternative to the LC1.

The SMT8 should work as well as long as it has the programmable outputs as well, this piggyback was also recommended to me by the same person who told me the AFR Gauge trick. The SMT6 that they discountinued can be found for around $150-$200
In theory it should honestly work if the ecu doesn't freak

I guess the question now becomes, who's gonna be willing to experiment with some of these?

[Loren]

Yeah, there are definitely other WBO2 solutions besides the LC-1, it's just the one I'm familiar with because I used it with the Megasquirt in my Spitfire.

[taKuto]

the emanage ultimate won't modify afr signals or o2, pic i found off the web for what parameters it changes

[Loren]

Originally Posted by PK198105

What could be tried , is to take an ecu from a bigger 4 and wire it properly. If all inputs and outputs are correctly wired we can achieve wider operational range.

We should petition Denso/Toyota to open the ECU to mods without sacrificing their trade secrets.

Wouldn't work, PK.

The ECU is still going to take the feedback from the O2 sensor and tweak the AFR to stoich. It's what they do.

Now, what I don't know is... what does the Yaris do when you go WOT? Because it's an economy car, is it still trying to keep the AFR at stoich? Does it have a WBO2 stock so that it can run lean? If so, does it use that to run richer at WOT?

Most cars that I've seen that use NBO2 simply go open loop at WOT, disregarding the O2 signal and running from a map. This is surely what the Yaris is doing now that I think about it, because we can see with the ScanGauge that the car goes Open Loop at WOT.

Soooo... if we're talking about making the car run a little richer at part throttle and during cruise, the WBO2 "cheat" should work. But, it's not going to do a thing for full-throttle acceleration.

To get more fuel at WOT, you simply need to fit larger injectors and/or increase fuel pressure. What the ECU is doing at WOT is looking at RPM, air temp and air flow and looking up a fuel requirement in a table. That translates to the pulses that are sent to the fuel injectors. The ECU assumes that the stock injectors are present and flowing within spec and that the fuel pressure is within spec. If you fit larger injectors, you'll flow more fuel, but you could run out of fuel pressure if you go too large. If you raise the fuel pressure, you'll also flow more fuel.

That, coupled with a timing controller (doesn't somebody make one of those for this car?) should take care of your needs... shouldn't it?

PK, think like a large corporation. What possible benefit is there for them to put any of their resources into releasing information about their ECU? Ain't gonna happen. They want performance-minded people to spend their money buying a sportier Toyota, not buying performance parts for a Yaris.

[eTiMaGo]

Originally Posted by Loren

Wouldn't work, PK.

The ECU is still going to take the feedback from the O2 sensor and tweak the AFR to stoich. It's what they do.

Now, what I don't know is... what does the Yaris do when you go WOT? Because it's an economy car, is it still trying to keep the AFR at stoich? Does it have a WBO2 stock so that it can run lean? If so, does it use that to run richer at WOT?

Most cars that I've seen that use NBO2 simply go open loop at WOT, disregarding the O2 signal and running from a map. This is surely what the Yaris is doing now that I think about it, because we can see with the ScanGauge that the car goes Open Loop at WOT.

Soooo... if we're talking about making the car run a little richer at part throttle and during cruise, the WBO2 "cheat" should work. But, it's not going to do a thing for full-throttle acceleration.

To get more fuel at WOT, you simply need to fit larger injectors and/or increase fuel pressure. What the ECU is doing at WOT is looking at RPM, air temp and air flow and looking up a fuel requirement in a table. That translates to the pulses that are sent to the fuel injectors. The ECU assumes that the stock injectors are present and flowing within spec and that the fuel pressure is within spec. If you fit larger injectors, you'll flow more fuel, but you could run out of fuel pressure if you go too large. If you raise the fuel pressure, you'll also flow more fuel.

That is another avenue, yes... Gotta find the page again, but the manual did mention about the ECU going to open loop above 4000RPM, but I am not sure if that is at WOT only or not. In this case, it becomes far easier to mess around with this. This is similar to what ZPI did, whereby they put the car in a constant CEL state, which also causes it to be in open loop

That, coupled with a timing controller (doesn't somebody make one of those for this car?) should take care of your needs... shouldn't it?

Timing, as in ignition timing? another kettle of fish, yeah... Power Enterprises has the Camcon which is used to change the VVTi timing, but I don't think it does ignition, you'd need a decent piggyback to do that, I think

PK, think like a large corporation. What possible benefit is there for them to put any of their resources into releasing information about their ECU? Ain't gonna happen. They want performance-minded people to spend their money buying a sportier Toyota, not buying performance parts for a Yaris.

But where's the fun in that?

[eTiMaGo]

I understand the logic, but think about this , if you are fooling the ECU with "normal" levels the ECU will respond with normal levels. so if you are running lean but need more fuel and you are tricking the ecu with normal levels it won't give you the fuel you need cause it will see that there is no need for more fuel.

What we need to be looking into is raising the threshold levels. Thats what they do at the factory , lets say the 1NZ-FE is capable of 170hp with AFR of 2.1 (totally pulled out of my butt numbers for purposes of an example) , the techs lower the AFR to 1.6 and the HP drops to 106 . All it takes is a proper fuel map loaded and the problems are solved.

Yes, but this would be used in conjunction with a piggyback or even a MAF resistor trick to raise the injector duty cycle in the first place, a two-pronged approach

Well, for a non-turbo/SC'ed car, the horsepower gains from doing this would be pretty minimal, really. In ideal conditions, an engine makes peak power when the mixture is stoichical (14.7:1 Air:Fuel ratio by volume). But, with forced induction, you want to run richer as a safety margin (go read LtNoogie's thread about his lean condition)

[eTiMaGo]

PK, I'm sorry but this thread is not really intended to debate the way Toyota handles its intellectual property

[eTiMaGo]

Toyota Canada:
1-888-869-6828


Hey, it is worth a try... But I think the idea of getting the local TRD guys to look at a US ECU would be more fruitful.

[eTiMaGo]

Aaanyway back on topic, as I noted before, it would be a good starting point to see how the Blitz controller that comes with the supercharger kit, connects to the car's wiring. I got my hand on some wiring information, and as expected, it plugs in to:

MAF sensor input
Intake Air Temperature input
A/F sensor input
Each fuel injector's output

So it stands to reason that it functions as a regular piggyback reading the various sensors and overriding the injector signals, and as Loren pointed out, this would probably only have an effect when the ECU's in open loop.

Since Long has a supercharger and a wideband installed, I'm gonna ask him to be a guinea pig (in the other thread about the AFR readings)

[Nexus1155]

i actually have a spare ecu in the drawer, but its mine, if anyone has any electrical engineering background and wants to help play with it id be more than willing to drop some cash on some more R&D

[ChinoCharles]

Not to be a downer or detract from anyone's efforts, but I think the focus of this thread should remain squarely on piggybacks. Hacking the stock ECU is great and all, but a separate working unit that will work in tandem with a stock ECU on stock settings is a much more viable alternative.

I will e-mail Perfect Power right now and get their thoughts on this. I'll post the e-mail as soon as I receive a response.

Perfect Power,

Hello. I am an owner of a 2007 Toyota Yaris in the United States. I am also a moderator of Yarisworld.com, the world's largest Yaris-oriented car forum.

I am contacting you in hopes that you can shed some light on the US market's longstanding problem with tuning Yarises using piggybacks. In short, after almost three years of the car being in the states we still haven't found one viable solution short of a standalone. AEM's FIC has been problematic at best. I know that you guys have the Yaris there in South Africa. Has the SMT-8 been a successful tuning solution for this platform? Can you offer any wisdom when it comes to tuning the tricky Yaris ECU?

If so, feel free to respond to this e-mail directly or make an account on Yarisworld.com and visit this thread:
http://yarisworld.com/forums/showthread.php?t=15350

We look forward to any insight that you may have to offer. There is a crowd of hungry tuners in the states that anxiously awaits a viable solution to this problem. If your piggyback will work with this platform, I think you can make valuable inroads into a largely untapped market.

Thank you very much.

Charles

[eTiMaGo]

don't forget to ask what is their solution for getting around the fuel trims!

[CASTREX]

I haven't seen "SPLIT SECOND's" name to be called on this thread yet.

These are the go to guys when it comes to tunning for the Large supercharged Toyota Engines.

Also URD (under dog Racing ) but I'm not sure if these guys actually use Split Second's stuff for their tuning devices....

Any ways, these 2 companies know their stuff on modern supercharged Toyota engines.

Not comparing the the Yaris with a Tacoma here... but still worths a shot.

http://www.splitsec.com/

www.urdusa.com

[largeorangefont]

Originally Posted by CASTREX

I haven't seen "SPLIT SECOND's" name to be called on this thread yet.

These are the go to guys when it comes to tunning for the Large supercharged Toyota Engines.

Also URD (under dog Racing ) but I'm not sure if these guys actually use Split Second's stuff for their tuning devices....

Any ways, these 2 companies know their stuff on modern supercharged Toyota engines.

Not comparing the the Yaris with a Tacoma here... but still worths a shot.

http://www.splitsec.com/



www.urdusa.com

Split Second makes some cool stuff. I know those guys through some mutual friends.

Also, are there Unichips available for the Yaris?

[CASTREX]

Originally Posted by largeorangefont

Also, are there Unichips available for the Yaris?

Unichip is what all the Thai turbo Yaris are using with good success. There are a couple of Thai members with the ZAGE turbo kit using the unichip.

However, UNICHIP in the US does not show any supported aplication for the Yaris. I remeber someone from this forum contacting them a long time ago but I gues nothing came out of that...

[largeorangefont]

Originally Posted by CASTREX

Unichip is what all the Thai turbo Yaris are using with good success. There are a couple of Thai members with the ZAGE turbo kit using the unichip.

However, UNICHIP in the US does not show any supported aplication for the Yaris. I remeber someone from this forum contacting them a long time ago but I gues nothing came out of that...

There is a UNICHIP that will work, they just dont have the plug and play harness to plug the chip into the US ECU.

I have a dealer tuning kit for the Unichip, so If I could get the right chip, I could concievably make it work.