Texas_Ace

I know all of that, done TONS of research AND put it into practice. You forgot to put Quench and swirl in your laundry list of things that the injectors have little to no effect on (really latent heat of fuels? that is the same no matter what injector you use). You act like you know more yet you can't give even a single solitary counter argument or even say what is wrong with what I am saying......Something doesn't add up.....

I also said exactly what you could expect from better injectors. You said you are not refuting it, so what exactly are you debating?

YES, you DO have to have an argument, you can't just go "your wrong, I am right" without anything to back it up.

I have provided both logic and a concise argument for my side, do the same.

As it is you just keep trying to misdirect.

Texas_Ace

You can make this work for sure, many cars do. The issue is long term reliability. These setups tend to not last as long and have a lot more quirks.

Flame Thrower

ok. lol. i will just take the half-million dollars worth of injectors i sell every year in my part-time job and cry myself to sleep.

as you already stated. 'I also said exactly what you could expect from better injectors' if that is true, what are your sources? no sources? made it all up? exactly where do you get your information? you refuse to say.

i'm not sure what you do to support yourself. one of us makes a pretty fair chunk of change doing this, and one of us does not.


FT

Texas_Ace

LOL, lets boil that down: "I don't like what you are saying but have nothing to say otherwise, so I will misdirect to try and confuse people from realizing this".

You can't just say I am wrong, you have to provide your own argument or by default I am right. Ever seen a court show on TV?

So, prove me wrong. Can't? Oh you mean I am actually right.

I never said you won't sell injectors. People spends BILLIONS of Gluten free foods, when it was proven that there is no such thing as gluten intolerance except in celiac disease.

I said that upgrading the injectors is a waste of money.

If you would provide ANY form of logical argument I could get into more details on why but as it is you have yet to even try to refute the points I have put out already. I refuse to move on until you at least try to do that.

Jomoka

How well documented is it that a stock V6 will go lean at WOT/high rpm anyhow?

Is that a 'stage 0 maintenance' issue (i.e. vehicle is not in good basic stock operating condition because of wear, age, plugged filters, etc)? Or did they supposedly not have enough flow capacity to handle WOT/redline even when new?

Does anyone know which years have the wideband O2 sensors on them? That would make it a bit easier to gather some data, otherwise you'd need to weld a bung onto the downpipe and install a whole WB controller and gauge.

Texas_Ace

The stock engine will not go lean with the stock injectors unless they are seriously clogged in which case you have other issues and a simple cleaning will having them running right again.

The stock injectors max out around ~190-200whp, in stock form the engine makes about ~140-150whp so you have a lot of wiggle room before worries of running lean creep in.

The wideband came in 99+ cali trucks and 01+ federal trucks but it is nothing that needs to be worried about like I said above unless you boost the engine. Even on my engine with all the bolt on mods you can do NA I am still lucky to be making 150-160whp.

vital22re

iTrader: (2)

I have your upgraded bosch injectors in my 3.4 with the sc. I will be removing them soon as i am running a piggy back only for my 7th injector and controller for my meth injection. Your injectors caused the long term to pull 4% fuel trim.
As TA stated, without a way to control the injectors they will dump fuel at idle and low rpm throwing off the fuel trims and there is no increase in power, nor increase in mpg. The ecu will fight to lean out the spray and because of this it tries to lean out just about constantly except for open loop.

Flame Thrower

yes. i sent out 20(?) sets of them last year. i was looking for a viable alternative to the 308cc sets that are still available. the 302cc were still problematic. several folks are still running them. i never brought them to marker for the 5VZ, but i continue to sell them for the supra.

now i am looking at the 260-270cc range. there are several vendors selling those currently. but it may or may not be worth the time.

Robb235

Just curious, but what are the long term reliability issues that you're referring to? It seems that if the injector size and the MAF housing diameter are increased by the same percentage, the ECU would never know.

I read about this same trick on another Toyota forum (ih8mud I think?), a guy did this on a Land Cruiser. It's been a few months since I read the thread, but I think the Land Cruiser was turbo'd, and the guy was having really good results rescaling the MAF and injector sizes.

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vital22re

iTrader: (2)

On a obd 2 vehicle the ecu will do everything possible to keep the mixture at the factory preset value. Meaning it reads what is coming out of the motor and correcting the trim values to factory spec.

Robb235

No offense man, but that kind of did nothing to answer my question, lol.

The MAF is calibrated for a certain diameter tube that it sits in. Say I change the diameter of the tube that the MAF sits in. If I make the tube smaller in diameter, the ECU will think the engine is inhaling more air than what it really is. And if I make the tube diameter larger, the ECU thinks it's inhaling less air than what it really is.

So say I make the tube 30% larger in diameter than what the MAF was calibrated for. The ECU will "see" 30% less air, and inject 30% less fuel than what it should (creating a lean condition that the O2 sensor will detect and try to correct). Now, we add 30% larger fuel injectors. Now the ECU is inadvertently adding 30% more fuel to make up for the 30% of air that the MAF wasn't seeing. The fuel trims should be pretty close to stock.

Get what I'm saying? This should keep the ECU thinking everything is in spec (AFR will still be 14.7 closed loop), but allow you to not run out of injector duty cycle in the higher RPMs for the supercharged and turbo guys.

My question is, what are the long term reliability Issues that TA alluded to?

EDIT: You actually would need to increase the area of the cross section of the tube by 30%, not increase the diameter of the tube by 30%. But you get my point. You change the tube diameter to get the ECU to inject less fuel, and then upsize the injectors to bring you back to "stock", except now your new injectors aren't maxed out in the high RPMs, and the ECU doesn't know anything has changed.

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Texas_Ace

You are correct in your breakdown but are forgetting one VERY key aspect.

If you adjust the MAF signal to account for larger injectors (by it with maf pipe size or using an SAFC, same result, the SAFC is actually better in a lot of ways since you can adjust the tune somewhat), then it will indeed adjust the fueling to match.

The issue is that is also adjusts the timing to match as well and when you install larger injectors and trick the ECU into injecting less fuel, it will in turn run more timing. The exact opposite of what you want. In some cases it will run MUCH more timing.

In the MR2 world it is pretty much a ticking time bomb whenever someone does this, the only real question is how long it will last.

There are some other issues as well, such as injector deadtimes ect that come into play but they won't have a major effect in most cases.

Another issue is that when tricking the ECU the ECU is never 100% happy as things just don't quite add up (nor should they). So it is always trying to figure out what is going on and you can have areas of the map that are just totally out of whack and should you get into them at the wrong time - blown motor.

Also gas mileage generally goes down when doing this among things like hiccups ect during daily driving.

In a nut shell, while it can be made to work it is more trouble then it is worth in most cases.

Spending a little more for a piggyback that can control the injectors directly (such as the AEM FIC) just makes so much more sense and while that has it's own quircks at least once you get it running right you have a setup that is 100x better then tricking the MAF voltage.

Robb235

Maybe I'm wrong, as I'm certainly no expert in this area, but I thought TPS and RPM played a larger role in the ECU's timing adjustment as opposed to the MAF. Is this not the case?

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Robb235

Do you have any threads you can link me to that discusses this?

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Texas_Ace

The MAF is the #1 sensor used for all tuning by a very long shot (or MAP in cars that use it instead). The others mostly effect the throttle enrichment, cold starts and other minor things.

RPM is always monitored as the ECU can not do anything without that.

None on me as they are hardly used anymore, people finally figured out that the few bucks you might save short term is not enough to replace the engine lol.

If you search old threads you can find something but the search on the site is majorly borked, I don't even try to use it anymore.

Robb235

I finally figured out who it was that upsized the MAF housing and injector sizing together. It was a guy with the username lilevo over at Ih8mud that did it to his Land Cruiser. So far there have been no mentions of too much timing advance with his setup. I believe he sized 440cc injectors with 3.5" MAF housing. It seems that with the larger MAF housing appropriately sized to the larger injectors, the ECU is adequately "fooled".

You can read his thread here (I think the part about MAF / injector sizing is around page 15):
http://forum.ih8mud.com/threads/diy-...-build.703295/


It would seem like we should be able to do the same thing with the 5vz. I think the stock injectors are... 240cc? And I think the stock MAF housing has a 2.5" diameter? I'm not sure if those sizes are correct or not, but assuming they are, if you were to throw in some 360cc injectors, that would be an increase of 50% on that end, and if you changed the MAF housing from 2.5" to 3" you're looking at a ~44% increase there. Seems like that would be an appropriate combination. Might be slightly richer, since the 3" MAF is only a 44% increase versus the 50% injector increase, but I would think that's well within the realm of the ECU to adjust via LTFT.


Thoughts?

vasinvictor

iTrader: (3)

If my meth wasn't working so well I'd love to try this. I generally don't care about trying hacks. My rig is all low buck, diy whenever possible etc. If the motor blows I'll go buy another doner for $600 and scrap the rest and break even. Rinse and repeat. I've been reading this with interest I just don't have anything useful to add. I really wish we could tune our ecu :-(

Texas_Ace

The stock ECU is pretty good at reading the knock sensor and adjusting timing accordingly to keep knock at bay. That doesn't mean the hack is working or that things are ok though.

As it is then a reactive feedback loop instead of proactive. AKA, the ECU runs too much timing, the engine knocks, it then sees the problem and reduces timing to stop the knock.

With this setup the knock always has to happen before the timing will be reduced.

When properly tuned it runs the correct timing and knock never happens in the first place.

Plus there are a lot of low load cells where there will not be audible knock for the sensor to pick up but will still be knocking along with the fact that most ECU's ignore the knock sensor during cruise conditions.

So in a nut shell, like I said before, it can be made to work but it is far from ideal.

Robb235

You say it's "far from ideal", so then how do you define ideal? I could claim that your meth injection (from when you were supercharged) is "far from ideal" as it is partially acting as a band-aid for under fueling issues. But it works, and that's what matters in the end. For me, "ideal" would be being able to tune the ECU directly, but as we know, that's not an option.

So where does that leave us? Stand alone engine management? That comes with its own set of issues including being able to control the trans, price, and lack of OBD2. So then what? Piggyback? Those essentially fool the ECU as well, and have a whole host of their own issues depending on what you go with and how you have it set up.

So what is ideal?

I'm also not convinced with the "adding too much timing" argument. I'm not saying you're wrong, TA, but your speculation seems to be the only point you've offered on the subject, meanwhile some else someone has already tried this method and has posted positive results, and no mention of too much timing advance. Granted it wasn't on a 5vz, but it's still on a Toyota platform around the same age as ours with similar issues to ours.

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Texas_Ace

Ideal is 100% for sure a standalone, no if's, and's or but's. The only issue with a standalone is price, everything else can be done for the right money unless your state is super strict and needs the OEM ECU in place, in which case you simply swap it out for the test.

Next to that second best would be a GOOD piggyback that takes direct control over the injectors and timing, such as an AEM FIC.

Everything else is a cheap hack that while it works has risks.

My meth injection setup was not idea at all, I could have got a pretty good bump in power had I had a standalone or piggyback as well.

The key is that the meth injection and 7th injector does not mess with the stock ECU at all, it works just as it normally would. You simply add fuel to keep the AFR's in check but the ECU is none the wiser. The meth injection also adds a TON of octane making it safer.

Far as the timing, it is 100% fact that if you skew the MAF signal to make the ECU think that less air is coming in and thus inject less fuel, it will also increase timing.

Timing at low load cruise can be as high as 40 degrees to maximize MPG. On the other hand when I was on the 7th injector the max timing it could handle was just over 10 degrees on 93oct.

Now with the meth injection adding a ton of octane it was actually able to run more timing then it does NA, around ~24-25 degrees. But that was only due to the meth injection stopping knock.

You could feel the engine knocking and the ECU reacting to it and pulling timing even with the 7th injector and not tricking of the MAF going on. on hot days or during extended boosting sessions. I would not have wanted to see what would happen if it was trying to run an extra 10+ degrees on timing before reacting to the knock. Only takes 1 good knock event to pop a ringland.

For the record I have tricked the MAF/MAP to run larger injectors on other cars int he past like I said before. It always netted me more issues then it was worth and I would have been better off just spending a bit more and doing it right the first time.