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

[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]

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]

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]

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

[ChinoCharles]

Thomas, I'm no tuning guy by any stretch. You know that. What I will do is refer them to a more knowledgeable party stateside so they can have some intelligent discussion, rather than me trying to type everything they say and saying "mm-hmm" a lot.

Would anyone like to volunteer to e-mail me their contact information so I can put them in contact with PP if they respond? charlesluzar@hotmail.com

[dallas]

That's some great team work and effort to get this stuff figured out, can't wait for some feedback.

[silver_echo]

Originally Posted by PK198105

yes and i did get to play with it somewhat , however it was mainly for maintenance and resetting the ECU. When you first connect the diagnostic computer it asks for tech password and then gives you the option to read, write or reset. i haven't had the chance to play in write mode since i was not allowed to but the tech says when they need to program the ECU it gets either reprogrammed at Toyota factory or they get a brand new one. None of them is able to reprogram the firmware.

is the diag computer handheld based or laptop based? my thinking is that if i can get my hands on the system, i might even be able to get into mine(i am starting the toyota t-ten program soon and with me being in that program, i might be able to spend some time fiddling with the programming), and with the ECU being only slightly different, i might be able to figure it out... my basic thinking was to try to fix the rich condition at WOT, but if i can figure out how to do that, it will open it up for tuning...

[ChinoCharles]

Hi Charles

Thank you for your email. I have forwarded your email to our Technical Team to see if there is a way to assist you. Normally the problems with certain cars are that some ECU's are really REALLY clever little units. Sometimes these ECU's detect that you are trying to intercept the signal and just don't like it and then causes endless problems. I am not too sure if this is the same with the Yaris as well but I let you know once I get more information from our Technical Team.

Kind Regards

Marcell Bruynius (Ms.)
Digital Data Systems (Pty) Ltd
Manufacturers of Perfect Power Automotive Systems
22 Arbeid Avenue, Strijdom Park, Randburg, Gauteng, South Africa, 2194
PO Box 35872, Northcliff, Gauteng, South Africa, 2115
Tel: +27 (0) 11 792 9805
Fax: +27 (0) 11 792 9818
Email: marcell@dtwebs.com
Website: www.perfectpower.com

Will continue to update.

[eTiMaGo]

sweet!
the urd afr commander or something like that, that castrex mentioned, looks quite intereting too

[eTiMaGo]

sweet!
the urd afr commander or something like that, that castrex mentioned, looks quite intereting too