@VF Tuner Looking forward to the Aussie wiring being sorted, I've been waiting for over a year for this fix with lots of emails backwards and forwards.
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VF Tuner ECU/TCU Tuning for the GX550 (4 Viewers)
- Thread starter VF Tuner
- Start date
Fair enough, I'll just stick with your tune then for now. Would just love to gain additional power with the tune in other ways than having to go with the expense of fully replacing the turbos.
I got a shipping notice for my tune kit back on 5/28, so glad to hear it's going out hopefully in the next day or two!
For a reference point, I have just the AFE intakes with a VF Tune and have had zero issues. I think the problems came when also installing the AFE inlet tubes.
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I don't mean to be a debbie downer, but see my post here: Afe intakes/inlets with VF tuner tune
The way modern cars are factory calibrated, intakes literally have zero effect on horsepower or torque unless they purposely engineer their products to (dangerously, IMO) lie to the ECU. If you want cheap power, keep all your fluids well maintained & your tires inflated property. Elsewise, you'll have to get your car onto a dyno for a custom remap to make any actual power from anything on the intake side.
As always - I will caveat that aftermarket cold air intakes do sound fantastic, and I do have a dealer option cold air intake & tune installed in my track camaro purely because it sounds so beastly. Zero horsepower gain.
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Hmm.. just adding another data point or two.. In both my STI (semi-daily) and Evo(gutted/caged per NASA 3000+lb) I recall seeing gains up top with only cai vs stock and this was prior to a Cobb protune. All done on EFI' Logics' mustang dyno.
In both cars, I felt an increase throttle response or turbo spool up just from cai (3" DP and exhaust even more so!).
For the gx, I did intakes and turbo inlets at the same time. This set up resulted in what I perceived as improved throttle/turbo responsiveness; albeit, with mileage going down (esp in sport s). Or.. perhaps this is another example of placebo effect. : )
That would be true for both the STI (pretty sure even up til today) and the Evo, as they're both running ECUs tuned using MAF or Speed/Density. This is the "older school" method where the car purely cares about air / fuel mixture. If you give it more air via an intake, you'll get more power because the ECU will have to compensate by adding more fuel - especially with the evo, which might use a cable operated throttle body.
Our car, like many other modern turbo cars, is likely running a torque-target model, where the ECU tries to produce a fixed amount of torque for a given situation, and then determines how much air & fuel it needs to achieve that. In a torque-target model, it doesn't matter if your intake allows the engine to intake more air, because the vehicle will detect it's producing too much power and simply close the throttle to compensate.
Installing an intake on the GX will create a temporary increase in torque, as the ECU re-learns the engine's reactions to a given amount of throttle body opening. After a few thousand miles of learning, I'd bet you could dyno it and see very little, if any increase in horsepower. If you have somebody tune your GX with the intake mods in mind, you will for sure be able to make more horsepower, but I really doubt the factory airboxes were the limiting factor to begin with. There's a Lake Speed video he did with Donaldson Filters where he showed that you can restrict like 80% of the flow to the airbox without meaningfully decreasing airflow reaching the engine.
Caveat: I don't have access to actually see how the GX's factory calibration works or how Toyota calculates / measures output torque. There's a possibility it's calculated purely based on load readings from the MAF, in which case an aftermarket intake with a cheaty, reshaped MAF housing could trick the ECU into making more power by producing inaccurate readings, but that is one sketchy way to do it, IMO.
Our car, like many other modern turbo cars, is likely running a torque-target model, where the ECU tries to produce a fixed amount of torque for a given situation, and then determines how much air & fuel it needs to achieve that. In a torque-target model, it doesn't matter if your intake allows the engine to intake more air, because the vehicle will detect it's producing too much power and simply close the throttle to compensate.
Installing an intake on the GX will create a temporary increase in torque, as the ECU re-learns the engine's reactions to a given amount of throttle body opening. After a few thousand miles of learning, I'd bet you could dyno it and see very little, if any increase in horsepower. If you have somebody tune your GX with the intake mods in mind, you will for sure be able to make more horsepower, but I really doubt the factory airboxes were the limiting factor to begin with. There's a Lake Speed video he did with Donaldson Filters where he showed that you can restrict like 80% of the flow to the airbox without meaningfully decreasing airflow reaching the engine.
Caveat: I don't have access to actually see how the GX's factory calibration works or how Toyota calculates / measures output torque. There's a possibility it's calculated purely based on load readings from the MAF, in which case an aftermarket intake with a cheaty, reshaped MAF housing could trick the ECU into making more power by producing inaccurate readings, but that is one sketchy way to do it, IMO.
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Nope
- Thread starter
- #530
We want to post all the updated tunes as ONLY the latest post TSB reflash version,
(edited)
We will be sending out tune versions of
8A2226028300
or
8A2226078000
(latest 2025/2026) and eliminate any possible cross confusion on calibrations.
(edited)
We will be sending out tune versions of
8A2226028300
or
8A2226078000
(latest 2025/2026) and eliminate any possible cross confusion on calibrations.
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Shot you a PM if you could take a look
- Thread starter
- #532
VF tuners latest update has released our custom Fast Flashing bootloader. (no more 10-15 minute flash times!)
Flash times now should be about 3 minutes or less.
next up full tune update release. (I know we promised this earlier, we really wanted to get these updates out, all done, and post out all updates after. My apologies)
Our fast flashing process is a clean, super efficient flashing method that
Dramatically reduces chances of programming errors/ecu needing recovery
Eliminates the LONG OEM Flash Valid checking at the end (this alone can take up to 2-3 minutes)
Handles the flashing process in a STRICT process that ensures the ECU should always be recoverable
Dramatically improves programming speed
allows you to flash maps much quicker!
AND, gets everything setup cleanly for our phone app which lets you swap tunes with your phone.
Flash times now should be about 3 minutes or less.
next up full tune update release. (I know we promised this earlier, we really wanted to get these updates out, all done, and post out all updates after. My apologies)
Our fast flashing process is a clean, super efficient flashing method that
Dramatically reduces chances of programming errors/ecu needing recovery
Eliminates the LONG OEM Flash Valid checking at the end (this alone can take up to 2-3 minutes)
Handles the flashing process in a STRICT process that ensures the ECU should always be recoverable
Dramatically improves programming speed
allows you to flash maps much quicker!
AND, gets everything setup cleanly for our phone app which lets you swap tunes with your phone.
📷 Lexus GX 550 Random Images
📷 Lexus GX 550 Random Images
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