Another S/C'd member worried about his AFR

[PETERPOOP]

no wideband here. you think i got 350$ for a gauge!? ;) i'll get one eventually. I'll have the scangauge on when I put the larger injectors and then eventually the 1zz throttle body.

[PETERPOOP]

Originally Posted by dallas

Has Blitz responded with anything?

Garm will let us know when they do. He sent them my a/f readings.

[whooppee777]

im going to use my blitz fuel controller to tweak the a/f ratios to where they should b

[kurokoma-kun]

Originally Posted by LtNoogie

I hear crickets chirping.

Ok well, here are my thoughts.

I'm not convinced that injector volume is the issue... the stockers are rated at 210cc? (someone please correct me if that's wrong) which should be good for 130 hp. But I'm no expert and I guess there's only one real way to find out, so I'll be very interested to see anyone's results with larger injectors (fuel pump, pressure regulator, etc).

The main issue for me is that I have neither the funds, time, access to professional tuning, nor personal interest enough to justify f***ing with the fuel system, at least not right now. Reason 1: the "plug + play" nature of the Blitz kit was one of the primary reasons for it's appeal to me, and I'd kinda like to just race and enjoy the car as-is for a few months. Reason 2: if I was gonna go to that much trouble I've have gone turbo, where the money and effort invested in tuning promises much greater payoff.

Now, a relatively simple mechanical upgrade intrigues me a great deal, which is why I've expressed interest in using my car as the guinea pig for the pulleys NST has said they are willing to develop (overdrive crank + u/d w/p). From what I can gather this set up should also help with any belt slip issues. The question of whether the fuel system can keep up with the increased boost produced has been raised--if it can't, then frankly I might abandon the project at that point... so maybe one of you interested in altering your fuel system woudl be a better candidate... if you think so, you might want to talk to Garm or Mike at NST about it.

[LtNoogie]

KK,

I too would have preferred that this was a pure bolt-on kit but I guess the word tuning must be an analogy to dialing in a radio to get the absolute best performance. While I still have this wild hair up my wazoo, I'm going to research this with consultation from my dyno guy. Believe me, Google and I are good friends.

No offense to your post but I need published numbers now for how our little car was spec'd. I've posted a request for information in the Performance thread. Anybody who can dig up published information is welcome to post it in that thread.

I have access to some of those things you mentioned. Time is tight so it takes me longer to get around to it. (it took me four months to get my gauges all hooked up)

So, have patience. If you see a Blazing Blue AT LB cream your time on YOUR autox course, ask the driver about his fuel system mods. Then refer him to me.

[kurokoma-kun]

Originally Posted by LtNoogie

KK,

I too would have preferred that this was a pure bolt-on kit but I guess the word tuning must be an analogy to dialing in a radio to get the absolute best performance. While I still have this wild hair up my wazoo, I'm going to research this with consultation from my dyno guy. Believe me, Google and I are good friends.

No offense to your post but I need published numbers now for how our little car was spec'd. I've posted a request for information in the Performance thread. Anybody who can dig up published information is welcome to post it in that thread.

I have access to some of those things you mentioned. Time is tight so it takes me longer to get around to it. (it took me four months to get my gauges all hooked up)

So, have patience. If you see a Blazing Blue AT LB cream your time on YOUR autox course, ask the driver about his fuel system mods. Then refer him to me.

You asked for opinions of other s/c owners, just my 2 cents. I dunno... I guess if I thought hp was the only route to autocross "victory" I'd have chosen a different car... for now I plan to focus on tightening the loose nut behind the wheel . But for me it's all just for fun anyway, and for now I've pretty much had all the "fun" tinkering with the car I care for.

As you were saying yourself just the other day, I'm not eager to be the first to blow up my motor, but who knows, in time I may change my tune too (literally, lol). Besides, when I bought the Blitz kit I was told I could expect up to an additional 30 hp: you are getting 27 hp; if I see similar results from this (relatively) stable and trouble-free upgrade I'll happily say I got a fair shake from Blitz. But as I said, I'll be very interested to see everyone's results with experiments, and sincerely wish everyone the best of luck

I assume you've been doing some reading around on scionlife too, since they have been using the same engine for longer and therefore are further ahead in their projects. It's tough to sort out the info from the asshattery at times, but good info to be had there.

[eTiMaGo]

Long, since you are the best equipped (SC + Wideband + Scangauge), I'm thinking of a few tests you could do to assess the functionality of the blitz fuel controller.

We need to answer 2 main questions, I believe:

1) Is the Blitz fuel controller working as expected, trying to force more fuel in the system?
2) If so, why does it not seem to do it at WOT (hence the lean condition)?

If I am not mistaken, the Scangauge should be able to display long term and short term fuel trims, right? I think this is the key to see how it is trying to fight the stock ECU.

As I mentioned in the brainstorming thread, any piggyback that tries to make the mixture richer, will be foiled by the O2 sensors, as these will detect the lower AFR. The way they feed this information back to the ECU is through the aforementioned fuel trims.

So, what I think we should do is set up a baseline fuel trim. Please keep in mind I am saying this out of theory and just a decent understanding of this ECU! Anyway, the first step would be make sure that you can actually get a reading for the fuel trims on your scangauge! If that's the case, the next step would be to clear the ECU's stored information so we can start with a clean slate. You could disconnect the battery, or pull out the EFI fuse which I believe is in the fuse box that's in the engine bay.

As a result fuel trims should be both at 0. Next, you'd need to drive around normally, but with the SC switch to OFF, and if possible with the fuel controller disconnected. This way we can know what is the default trims that your stock engine setup will generate. I am not sure over what period of time the long term fuel trim is calculated, but it is essentially an averaging of the short term trim over time. I'd guess a day of normal driving should be enough. Also, during this time, you can use your wideband to verify that the AF ratio will be pretty steady around 14.7 as this is what the ECU strives to achieve.

So once we have this data, it would be time to see how the Blitz fuel controller reacts when the car is in closed loop, SC activated and car driven in a normal fashion. So, reset the ECU, reconnect the fuel controller, set the SC to LOW, and drive! Try to avoid mashing the pedal and going over 4000RPM too as these would trigger open loop mode and we want to keep that out of the equation.
If the fuel controller is working as expected, it will try to force a rich mixture, which the ECU will then counteract. You will *probably* see a rich mixture on your wideband at first, until the ECU calculates the correct fuel trim to counter that. So, after a day of driving around like this, we would need to compare the fuel trim values to our baseline. If we see pretty big negative fuel trim values, this means the fuel controller has worked as expected, and the ECU has responded as expected.

If the fuel trim is unchanged from stock, then there are two possible explanations: The fuel controller is not working, or it is smart enough to know to leave the ECU alone when in closed loop mode (not likely)

Now for Part 2, WOT diagnostics, unfortunately I can find very little information about open loop operation in the manuals, so it'd be quite hard to test anything properly.

Only thing I can think of, is to compare your wideband readings at WOT with the fuel controller unplugged, and then again with it plugged in, under the same conditions (reset ECU before each test) and see if there is any difference in the readings.

I know we can't really compare readings between our cars which are modified quite differently, plus the USDM and Thai ECUs are different, but I have a basic narrowband AFR gauge, and I can see, when I push the car into open loop, the needle jumps up to 12:1, even as rich as 11:1 sometimes...

So... do you feel like giving that a try?

Oh and on the subject of the stock injectors reaching their limit, those work using PWM, I think the only way to see their duty cycle would be to connect an oscilloscope or similar? And, even if you were to put in bigger injectors, I think you'd hit the same hurdle, the ECU will detect too much fuel and trim it back. Although, under open loop, it may just work... hmmmmmm

[eTiMaGo]

actually... better ignore all that for now, it seems the long term fuel trip is nonvolatile so resetting the ECU will not affect it, you'd need the proper Toyota scan tool to reset it

[Doc Zaius]

Wow... Thomas writes a lot!

You guys (& gals) impress me... lots of good ideas and willingness. I'm more in KK's boat though... things have been ok for me (more-or-less), and I'm hoping to do as little as possible from now on. Wow, I'm lazy!

BTW, after having driving around with my 'charger turned off most of the winter and having some weird idling issues, my Toyota tech said my fuel trim was at -15% (trying to lean it out). Food for thought. I'll take it to him again later in the spring once I've been driving around with the S/C on for a while and see if there's any change.

[LtNoogie]

Originally Posted by eTiMaGo

If I am not mistaken, the Scangauge should be able to display long term and short term fuel trims, right? I think this is the key to see how it is trying to fight the stock ECU.

I did not think the ScanGauge could display fuel trim. I'll have to look it up in the manual. If anyone knows how to program it to do so, you can save me the research.

What kind of units would it be displayed as?

[LtNoogie]

Ok, you guys wait until my next dyno pull after my tuning. When you see my 119HP up from the 117HP on the last pull, you'll be jealous.

[bearda]

Originally Posted by whooppee777

now this guy also works at the shop in northern virginia which has a high reutation so this isnt some averge joe, hes a tech at this shop that knows what hes talking about.

Which shop is he running out of? Ptuning?

[turboecho2005]

Originally Posted by Nexus1155

I don't know if they have a standalone and a plug in play but ive only seen standalone, but im sure you can wire it in tandem.

did you install it on a yaris or an echo?

Megasquirt can be used both as a standalone or a piggyback but its not plug and play.

It was used as a piggyback in my echo when i still has the 1nzfe motor. Timing was still controlled via the stock ecu. The megasquirt took care of fuel.

There was an issue trying to control the VVTi (this was back in 2006) but i am sure someone has figured it out by now. However controlling VVT on the blacktop motor wasn't an issue.

[HTM Yaris]

I think you peeps are looking in the wrong place . I bet if you put your stock exhaust back on you will find your HP and torque . Remember that thing called "back pressure" . You peeps have opened your exhaust too much , IMO .
Opening an exhaust too much will result in a loss of HP and torque . Either you need more airflow to fit your exhaust or you need to downsize your exhaust to create the proper back pressure .

Want proof ? Just check out Noogie vs Poop setup . Poop has the larger exhaust and lower numbers .......

[LtNoogie]

Originally Posted by HTM Yaris

Want proof ? Just check out Noogie vs Poop setup . Poop has the larger exhaust and lower numbers .......

Ooo... don't remind him of that more that three more times!

[kurokoma-kun]

Originally Posted by LtNoogie

Ok, you guys wait until my next dyno pull after my tuning. When you see my 119HP up from the 117HP on the last pull, you'll be jealous.

*sigh*

it's true

[PETERPOOP]

Originally Posted by HTM Yaris

I think you peeps are looking in the wrong place . I bet if you put your stock exhaust back on you will find your HP and torque . Remember that thing called "back pressure" . You peeps have opened your exhaust too much , IMO .
Opening an exhaust too much will result in a loss of HP and torque . Either you need more airflow to fit your exhaust or you need to downsize your exhaust to create the proper back pressure .

Want proof ? Just check out Noogie vs Poop setup . Poop has the larger exhaust and lower numbers .......

I think you are wrong. You also forgot that my dyno run didn't go to 6500 RPMs like noogie's. You can see in my chart that the HP was still rising at a strong rate. It stopped at 6200 RPMs. Also, I was on a dynapack, not dynojet. Dynos are different.

I am going to dyno on a dynojet soon, run it to 6500rpms, and I can guarantee you it will be higher than 117hp on the dynojet.

I do agree that my larger exhaust lost torque, but HP, especially in the higher RPMs, naw.

But I am going to be running a 2" 24" resonator and a hi flow cat soon, so that will probably bring me some back pressure/torque back.

[Nexus1155]

I dunno, I mean it is a small engine, but only upping it to a 2.5 exhaust... I mean i can see a 3" losing serious pressure because its only good past 500hp, maybe you should try a 1 inch exhaust? LOL BRAAAAAT KABOOM!