Toyota Tacoma 3.4L K-Line ECU Reflash interest

I'd expect a proper engine map to be able to pull way more than 10hp out of a boosted engine.

It's impossible to say what you could get out of a stock engine because no one really knows what the engine map looks like and whether there is much room for improvement. Given how strongly built the bottom end of the engines are it's possible Toyota significantly detuned the 5VZ for emissions or reliability

 

That would be awesome. Im excited to see what can be done and how much better it could be. A coworker was showing me his dodge 1500 with all the NA stuff he’s done. Told me he got like 50hp from his tuner. Its disappointing that there’s been such a lack of support for these trucks with the supercharger.

But how strong can these motors really be with the cast everything on the bottom end?

I’d like to add that Gadget at one time was supposedly working on a VVT setup for the 3.4l. Guess that didn’t pan out like the 3.4 rotrex or 3.4l turbo kit...


Here’s a screenshot where Gadget mentions cam timing control through the unused feature on the 7th injector or the AFR calibrator. Can’t remember which one.

 

You can't just make a "canned" tune for forced induction. At what boost? The 5VZ injectors are not able to handle much more than 5-6 psi from the TRD blower. If you replace the injectors, that tune is shit.

Even if you tune for a stock engine with a stock TRD blower, basically you have to tune so conservatively, its just going to be a massive fuel dump into the engine to make sure you don't experience pre detonation.

If I'm going to pay for a tune, I'd spend the extra $150 for a standalone. OVTune can invest in whatever they want but I'm not sure what they hope to gain unless they do what URD does with the 2nd gen and make a performance kit that compliments the tune.

The 5vz has intake runners a mile long and 2 1/4" exhaust. Its choking on itself at around 3500 RPMs. Everything about the engine design, things that can't be tuned, is for low end torque. Unless OVtune replaces the intake runners, Throttle body, injectors, and exhaust, its not worth tuning.

The 5VZ was designed in the 90's and wasn't tuned for emissions. It was designed for low end power. Without cam timing adjustment, variable intake runners, port and direct injectors, and variable exhaust flow profiles, engine tuning is pretty much all mechanical until it comes to adding fuel. Then its just a simple math problem to calculate air flow and fuel flow that makes a 14.7 AFR. They only exception is engine timing but if you think you can find a safe timing advance that works for all 5VZ's, get ready for a class action lawsuit when people start blowing engines.

 

Maybe @OVTune needs to respond to that. But as far as exhaust goes better flowing headers and a larger ID exhaust is an option. And I would think OV time could make adjustments based on mods, feedback, and logs but we’ll have to wait and see. Here’s a quote where they mention custom tuning options and a CAN logger. I’m assuming it’s some sort of data logging? I’m not sure.

 

Y'all need to read that last line again...

I read that as "We'll sell you a cable, give you the software ... and you're on your own." So, @StAndrew 's comment of "get ready for a class action lawsuit when people start blowing engines" wouldn't apply.

Also, all the delegating work to OVTune to provide maps for a vehicle they don't even have to test with ... that's likely not going to happen.

For those interested in this and have a compatible vehicle (03/04 V6 Tacoma), you may want to read the thread again...

 

They also mentioned making a tune for the TRD supercharger.

 

Here.

 

Shoot with some locked computers all you need is the ecu definition and a tactrix cable and all the tables are there and ready for a dyno tune w/o piggyback. BTW the definitions are free for Subaru’s that can’t piggyback with an accessport, I wouldn’t expect to get a definition free though. There’s a computer guy that works for Denso US and is on the supra forums that mentioned the 5VZFE ecu being upgraded, but not tuned he said the components in them can be changed but up to 02 the ecu’s are mentioned as being dumb and not even throwing codes that would normally show these days. I’d like to see a nerd hack the 1st gens just for the definition, I know a tuner that would have a line out the door for our trucks if that info ever gets leaked (unlikely) though.

 

These engines are way detuned and can handle some serious boost especially with the crank out of a 92 camry 3VZ. I talked to Gadget today and there is a taco that put out massive hp, twin turbo and they had to detune it by 1/2 the horsepower. I’m not gonna say how much hp because people like to throw shit around about that issue and won’t do the hard research for themselves. Toyota made a winner with the 5 VZ is all I’ll say bout that. Keep oil and coolant in it and you can push it hard without worries.

 

I’ve heard the rod bolts are the area that fails the most often.

However there is a guy on here with 350HP and 400tq on a turbo and standalone on a stock motor. The TRD S/C probably can’t push that much unfortunately.

 

You need a tactrix. But we can get you them (legit) ones cheaper.

The plan was to offer you guys the software / maps / help / tune-ability.

But the actual tuning part is up to you guys.
As far as stock ecu vs piggyback...when you have stock ecu control, using a piggyback is a joke.
Who actually wants to graduate from 90s tuning and stop using extra injectors for fuel?

Rev limits.
Sensor scaling.
Throttle DBW / load
Ignition
Fuel
Etc...


Give me about an hour or two I'll show you guys some of the tables in the stock ecu. Just let me know what you want to see.

I really enjoy tinkering with older ECUs, and have a good handle on the code. It wouldn't hard to cook up some features too ( custom code ).

Not planning to charge absurd amounts either. This was more of a side project than actual business for this old K line stuff

 

What I would like to see is an option to adjust transmission shifts and lockup clutch engagement speeds to tune the trans to your driving habits. If they can crack too code for direct ECU tuning that could be helpful. The biggest draw back to piggy back tuners is that some dont allow timing advance, only retarding.

 

Thank you for your commitment and time with your side project, @OVTune !!!

 

Is it possible to change timing based on the gear?

 

Transmission shift tables and other transmission related components can be tuned.

(shift map for example) Shift maps 1 > 2, 2 > 3, and 3 > 4 ( up and down),
You can see how there is so much more possible with transmission tuning if you don't use half the map for full throttle like toyota does (axis can be tuned)
Tune-able tables would be >
Engine :
Fuel controls
Ignition Controls
Torque controls / load
Throttle control

Transmission:
Shift tables Up
Shift Tables Down
Torque Converter





ignition timing:
(these numbers may not be accurate, have to double check code for conversion) However this is what the stock timing map looks like.



Full throttle fuel (by rpm)




obviously there are many more tables but here is just a few to check out.

 

Will it log data, @OVTune?

 

Yes. However K-line datalogging is absurdly slow, so it would be best to only log a few things at once. Like bare minimums, RPM, Ignition, fuel. or RPM, fuel, TPS. It does ok when only requesting the minimums, but datalogging a lot of PIDs will result in a terrible log.

 

@OVTune is there a good resource to learn how to do all this?

 

I would love to make some cool videos but finding time is the issue.
Basic EFi knowledge would be needed to really tune it, but it's honestly not all that hard.

lets get some people going with it and we can work out how to get you guys the info you need on proper tuning

 

I'm still in. NA for now, Supercharger likely end of the year, but will provide useful feedback on the software and experience when I spend some time with my friend in Oregon the end of the month.
I sent you an email, so shoot me a response there or PM me here on how to purchase the Tactrix cable through you and get the software.