GR Yaris JB4 box
- Thread starter Onehp
- Start date
Michael Knight
Totally Hooked
Typically you can adjust fuel trims and also fuel pressure which then affects to afr. Afr is results of selected fueling and boost variables, not directly adjustable per se.
No fuel trim adjustment (fol), AFR can be influenced by changing MAF bias but it is still beta (=under development)
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So me and my friend got wire loom that wasn't connected in the right order, we found the issue eventually and now they are working.
Our initial 3rd gear 50-130km/h times are 0,6s or 10% faster on average on MAP1, so very noticeable difference. 110-130km/h is down from 1,9s to 1,6s, indicative of top end power. So more power everywhere. But note, we both have HJS + IC installed, without hardware we've seen many times with other boxes there is not much more power as car is running hot already.
From previous good experience with JB4 it is still quite obvious this is a Beta:
- PIDs missing (misfire/cyl, fuel trims, cat and ic temps as the most important) - can be added with new fw
- Some scaling issues on the ones that work - idem
- Boost plugs don't fit well - manufacturer looking into it
- Not the best driveability on part throttle, again something I've seen other boxes struggle with but JB4 with OBD and e.g. throttle data has the best chance in adressing this later on.
Friend will do Dyno next week or so, then we can show some data. He is running map1, I have made my own conservative map6 to suit my goals.
Our initial 3rd gear 50-130km/h times are 0,6s or 10% faster on average on MAP1, so very noticeable difference. 110-130km/h is down from 1,9s to 1,6s, indicative of top end power. So more power everywhere. But note, we both have HJS + IC installed, without hardware we've seen many times with other boxes there is not much more power as car is running hot already.
From previous good experience with JB4 it is still quite obvious this is a Beta:
- PIDs missing (misfire/cyl, fuel trims, cat and ic temps as the most important) - can be added with new fw
- Some scaling issues on the ones that work - idem
- Boost plugs don't fit well - manufacturer looking into it
- Not the best driveability on part throttle, again something I've seen other boxes struggle with but JB4 with OBD and e.g. throttle data has the best chance in adressing this later on.
Friend will do Dyno next week or so, then we can show some data. He is running map1, I have made my own conservative map6 to suit my goals.
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Dyno was broken so that did not happen.
Don't expect big progress untill Burger get their hands on a GR Corolla.
(Part) Throttle response has been bad in map1 at times, too much boost request, engine going into protection. The firmware update helped somewhat.
I've made various map 6 that suit me and my friend better. For me it's purely subjectively - consistent throttle response and nice power delivery*. Friend did two trackdays and now has a map6 that is as fast while being much less aggressive in requests then the map1.
I guess in the end, it's probably similar to off the shelf well developed tuning boxes and there is, so far, only so much these can do. But I prefer the control of being to able to change myself and see what happens. So far I'm happy with the results, remaps have their own quirks and downsides...
*to verify the butt dyno is not imaginary we do sometimes do 50-130 runs in 3rd and our cars, with HJS and IC, are definitely quicker even in almost 30 °C ambient, about 0,5-0,8s depending on how aggresive the map, compared to fully stock
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great, I'm glad there are people collaborating to improve the box. It is one of my things on the list and the jb4 is among my first options
Michael Knight
Totally Hooked
Terry @BMS got finally a GR Corolla for few days with JB4 and he was able to familiarize with the car.
Corolla has slightly different setup in terms of HW (fueling, boost sensors etc).
Corolla has slightly different setup in terms of HW (fueling, boost sensors etc).
Michael Knight
Totally Hooked
assuming yes - latest tests with GRC the AFR was adjustable with Fuel bias? So assuming yes its adjustable
Update
The JB4 has received new firmware with GRC input and I can now recommend it with reservations for anyone looking to have a solution with own boost control (one can add up to approx 0,2-0,25 bar in different parts of the rev range), MAF and indirect AFR control, easy (and necessary?) logging of what one is doing and resellable. Possibly more developments down the line that could add even more power but personally I probably pass on that... Reservation is that the boost plugs on the wiring harnass don't fit well and need some trimming and adjustments to make fitting/removing/refitting easy.
The JB4 has received new firmware with GRC input and I can now recommend it with reservations for anyone looking to have a solution with own boost control (one can add up to approx 0,2-0,25 bar in different parts of the rev range), MAF and indirect AFR control, easy (and necessary?) logging of what one is doing and resellable. Possibly more developments down the line that could add even more power but personally I probably pass on that... Reservation is that the boost plugs on the wiring harnass don't fit well and need some trimming and adjustments to make fitting/removing/refitting easy.
MarcoB
Absorbed member
- Feb 2, 2023
- 59
- 72
- 18
To be honest I would have preffered this device over my DTUK V2 if I knew this was available at the time (but I think it came to the marked for the GRY some time later).
Sure a lot of development was done with the DTUK, and I am really content with it. But to be in control myself, plugged into the OBD and to be able to check whether if it's safe by doing the logging myself on the real parameters is a big plus.
Sure a lot of development was done with the DTUK, and I am really content with it. But to be in control myself, plugged into the OBD and to be able to check whether if it's safe by doing the logging myself on the real parameters is a big plus.
It depends really. Contrary to other platforms, the community isn't big (yet) so we had to figure out a lot of stuff ourselves, being Beta. At the same time, if you are used to be in control (had two jb4 before on previous cars) it's not really an option to leave it all in the hands of someone who can't either see what your car is doing. And from our limited experience, on paper the same cars react quite differently to the same input.
But if you just want a install and forget affair, then maybe not the best option. All options have their pros and cons.
But if you just want a install and forget affair, then maybe not the best option. All options have their pros and cons.
Aswering Q in another thread: https://www.gr-zoo.com/threads/inconsistent-boost.1162/post-70269
Log 4th gear showing everything that matters. Also have custom AFR tuning and giving nice ignition timing too (98) 21C ambient. Here not reaching the +4psi target everywhere, sometimes it does so it can stay...
I'm using the JB4 because I don't want to run it in the classic sense of getting out as much boost as is possible. I'm running only 1psi more midrange up till 5500rpm which after much experimenting gives the best increase in response without feeling boosty, after that I ramp up the boost add so I don't get the drop off in power in higher revs, peaking at 4psi at 7k rpm. Car responds well to the latter as I have better flowing hardware to support that.
Log 4th gear showing everything that matters. Also have custom AFR tuning and giving nice ignition timing too (98) 21C ambient. Here not reaching the +4psi target everywhere, sometimes it does so it can stay...
Sekred
Totally Hooked
- Dec 18, 2021
- 412
- 521
- 93
So boost peaks at around 24psi and tapers off to around 16psi at the redline?. Am I reading the graph correctly?.
Are you using Bluetooth to log from the JB4 App?.
Sorry for all the questions but there is a lot going on and graph is a little narrow for me to get my head around everything.
Yep bluetooth JB4 phone app. Very easy.
Boost (lower blue) sits around 22psi midrange or 1psi more then stock (white line is boost ecu sees), ends up at 16-16,5psi at 7k rpm while stock would be approx 12,5psi. Red line is boost demand, if white dips under it's not making the full request. I imagine that many boxes sit there a lot of the time...
It's basically a minor modification of the stock mapping, rendering imho a lot more driving fun when it's rewarding to rev out. Would be even cooler if boost/torque didn't drop much to redline but then looking at a very different setup, anyway the way it delivers power is plenty fast to have fun on the road with a nice blend of mid range torque and top end power.
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Reliability wise, torque is barely up and heat up to 6000rpm is a lot lower then OEM due to my mods (intake (lowe IAT+better flow), IC(lower Charge temp and better flow) and HJS cat(lower EGT and better flow) that all reduce thermal stress. Perhaps it adds a bit heat at 7000rpm but you sit there so short time that I estimate overall heat load to be lower then stock. Just to say I have no qualms at redlining the engine whatever circumstance allows.
Litte update, a friend JB4 user (not me) is now alfa testing a BCM or boost control module. This add-on should help with controlling boost better and more freely. First results looks like it can hold upwards 0,2 bar more boost in a stable manner, which is quite a lot and this should close the gap to remaps, while keeping own control and having something resellable.
shoeihsieh
New member
I have this product and have been running it for three months. I can tell you that this product is not perfect and there are many problems that cannot be solved effectively. Simply put, it is rubbish, so I decided to sell it.
