[ddnspider]

Originally Posted by Terry @ BMS

On launching what works best is brake boosting as aggressively as possible. Let it sit in brake boost for a few seconds to spool up.

Are you actually seeing boost at launch with this method or just less vacuum? Any thought to a launch mode?

[JCB]

Isn't launch mode in a slushbox pretty much just automatic brake boosting? The torque converter will only spin so fast with the wheels stationary so if the turbos can't provide boost under 2600RPM or so there really isn't much you can do about it.

[ddnspider]

Originally Posted by JCB

Isn't launch mode in a slushbox pretty much just automatic brake boosting? The torque converter will only spin so fast with the wheels stationary so if the turbos can't provide boost under 2600RPM or so there really isn't much you can do about it.

No. brake boosting is not the same as a real launch mode. Look up things like a 2 step rev limiter for example. Being able to adjust air/fuel and timing and wastegate position allows you to sit in real boost at a fixed rpm on launch, not whatever boost you get to based on whatever load you can manage while sitting stalled up.

[JCB]

Kind of a chicken and egg thing...car can't spin the torque converter past 2500 RPM while stationary, unless you can somehow create more boost. The boost doesn't come on until revving past 2500. I guess the timing adjustments and fuel dumping into the exhaust could create some additional boost, which may in turn provide enough power to spin the torque converter a little faster? I think that is beyond what the JB4 is designed to do though. What kind of boost is generated at launch on a fully tuned Q50? Are custom tuners able to pull off significant boost at launch? All the logs I see on this site and with my car - launch is at 2500 or so and there is no significant boost build until a bit under 3000 RPM.

[ddnspider]

Originally Posted by JCB

Kind of a chicken and egg thing...car can't spin the torque converter past 2500 RPM while stationary, unless you can somehow create more boost. The boost doesn't come on until revving past 2500. I guess the timing adjustments and fuel dumping into the exhaust could create some additional boost, which may in turn provide enough power to spin the torque converter a little faster? I think that is beyond what the JB4 is designed to do though. What kind of boost is generated at launch on a fully tuned Q50? Are custom tuners able to pull off significant boost at launch? All the logs I see on this site and with my car - launch is at 2500 or so and there is no significant boost build until a bit under 3000 RPM.

I dont think you fully understand how a 2 step works or launch control works. You don't need more RPM if you can control spark and fuel and wastegate position. These motors make peak torque starting around 2500 rpms. With launch control/2 step the motor will literally sit at 2000/2100/2200/etc. rpms, and generate boost due to adjusting timing and fueling. The goal isn't to increase launch rpm. The goal is to build significant boost at an rpm that is below the stall speed of the factory torque converter. This is common place on other platforms and with aftermarket 2 step rev limiters.

[JCB]

You are correct - the timing and fuel adjustment aspects are the parts I don't understand, but also the parts that seems out of the capability of a JB4. Be curious if the custom tuners have been able to solve this issue and produce boost below 2500 RPM on our engines. I have played with the wastegate settings at low RPM and it does not seem to have any effect.

[ddnspider]

Originally Posted by JCB

You are correct - the timing and fuel adjustment aspects are the parts I don't understand, but also the parts that seems out of the capability of a JB4. Be curious if the custom tuners have been able to solve this issue and produce boost below 2500 RPM on our engines. I have played with the wastegate settings at low RPM and it does not seem to have any effect.

Turbo spooling/boost is about loading which is heat and pressure. In the case of a manual transmission car, you typically retard timing and add fuel to build boost by sending unburnt fuel into the exhaust to the turbo. In an auto, you typically add timing and pull fuel to get the turbo lit. The best way to do this is to alternately cut spark from each cylinder too, which I don't think the JB4 can do. When you set the secondary rev limiter, it'll bounce against the rev limiter letting the increased load get the turbo going. My thought is if the JB4 knows youre in 1st gear from a stop, or even if you have to press/hold a button on either the app or the steering wheel. It could pull fuel (JB4 has control of this), keep the wastegates closed (JB4 has control of this), and see if its possible to either adjust timing or hold an rpm to create a launch mode.

[Serstylz2]

To answer, I am tuned and with LC I am leaving the line at 10psi. Could do more but ... RWD/traction ��

[ddnspider]

Originally Posted by Serstylz2

To answer, I am tuned and with LC I am leaving the line at 10psi. Could do more but ... RWD/traction ��

Exactly....its definitely a game changer. Drive that thing to FL and we can mount up my DR's

[Pryce1155]

Hey all I already created a thread on the official q50 form, I’m just gonna put the link to that and hopefully you all can go over there and tell me if my logs are ok since I had to separately upload each photo of log chart. Thanks !

Jb4 logs (map2,5,6) advice needed | Infiniti Q50 Forum

[Serstylz2]

Originally Posted by ddnspider

Exactly....its definitely a game changer. Drive that thing to FL and we can mount up my DR's

I would love to feel my car absolutely dead hook one day... a guy can dream

[radar24]

Can I please get someone to take a look at my log. 2017 Q50 RS on Shell 93 map 6.

[SkylineDude]

Hi All, I’ve got myself a JB4 without fuel/EWG wires and upgraded to v9 beta firmware. This is for red sport on 91 octane, sea level, 68-78 temperature, car is stock aside from JB4.

Attached is what I did for Map 6. Would that be ok to start and do some runs? Am I correct assuming in my case without the optional wires, wastegate position, PID gain, and shift reduction do not matter? I also do not have any bits (bit 7 for red spor) set.

Upd: added the log, very short run

[JCB]

That is a pretty conservative place to start. You may want to do a run or 2 on Map 1 1st and check your logs.

[marmet2010]

bonjour tout le monde, je suis un petit nouveau du Québec avec un infiniti q60 3.0t ss et jb4 en commande, je vais avoir besoin de votre expertise pour bien comprendre le fonctionement du jb4 et lire les journaux lorsqu il sera installer dans mon auto

merci beaucoup

hello everyone, i'm a new kid from Québec with an infiniti q60 3.0t ss and jb4 on order, i will need your expertise to fully understand how the jb4 works and read the logs when it is installed in my car

thank!!!

[roshg]

Had a few questions to ask regarding current topics here:

Good idea to have the fuel wires turned-on even if we running min E15 mix of E85? I heard E85 leans it out anyways - true or not?

Brake boosting - have to make sure Traction Control is turned off. So basically brake boost for 2-3 secs and then let go?

[marmet2010]

good evening, for maps 1, 2, 3, 4, 5, is it possible to make changes using the android app, or it is impossible to make adjustments, v8 firmware ?????


for map 1 and 2, are the fuel control wires needed???? what are the advantages if I use them????
91 octane

thank you

[JCB]

Map 6 is the only map you can customize the boost settings...1-5 are preset maps progressing upward in boost. Start with 1 and work up, checking the data log each time to ensure the car is handling the extra boost without pre-ignition (knock). You are looking for large drops in timing (Ign1 on the log) that occur as the car climbs through the rpms in a gear. It is best to do a 2 gear pull (2nd then 3rd). In 2nd take it to redline and 3rd at least to 6400 or so (redline if you are comfortable and safe with the speed - some daredevils do 3rd to 4th and are REALLY moving at the end of the run). Ign 1 will go to zero at the shift but should recover to between 6 and 12. Sudden drops of ~ 2 or more in ign1 is a sign the care is fighting knock and pulling ignition timing to compensate. Hard to explain but go back through the site and look at logs that Terry said "looks good" and review Ign1. You will start to get the idea.

On 91 Octane you may not be able to go all the way to map 5. I am finding that Map 5 is kind of the limit on 93 octane on my luxe 3.0t (totally bone stock).

Regarding fuel wires - they provide marginal extra power at high RPM. Certainly not necessary but if they came pre-installed on your JB4 you might as well hook them up unless you plan on pulling the unit out often for dealer visits.

[marmet2010]

Originally Posted by JCB

Map 6 is the only map you can customize the boost settings...1-5 are preset maps progressing upward in boost. Start with 1 and work up, checking the data log each time to ensure the car is handling the extra boost without pre-ignition (knock). You are looking for large drops in timing (Ign1 on the log) that occur as the car climbs through the rpms in a gear. It is best to do a 2 gear pull (2nd then 3rd). In 2nd take it to redline and 3rd at least to 6400 or so (redline if you are comfortable and safe with the speed - some daredevils do 3rd to 4th and are REALLY moving at the end of the run). Ign 1 will go to zero at the shift but should recover to between 6 and 12. Sudden drops of ~ 2 or more in ign1 is a sign the care is fighting knock and pulling ignition timing to compensate. Hard to explain but go back through the site and look at logs that Terry said "looks good" and review Ign1. You will start to get the idea.

On 91 Octane you may not be able to go all the way to map 5. I am finding that Map 5 is kind of the limit on 93 octane on my luxe 3.0t (totally bone stock).

Regarding fuel wires - they provide marginal extra power at high RPM. Certainly not necessary but if they came pre-installed on your JB4 you might as well hook them up unless you plan on pulling the unit out often for dealer visits.

thank you very much, in full this information that I was looking for to start my tests

[zkyzork]

Have anyone run into problem with enabling fuel control bit. I went in the options setting and set bit 0 to on and save it. Went back in again it show to be off. Am I missing something here? Firmware been updated to the latest and fuel wires come with pre-built in the harness. Thanks

[roshg]

Hey guys I was searching and I don't this question ever been answered before, but when looking at our logs, what is the max trim #? Is Max Trim 44 or 50?

[JCB]

zkyork - are you trying to change the setting offline? Your app has to be connected to the JB4 when making configuration changes. Don't know of anything else that would cause the setting not to save.

[JCB]

My trims never go above 44 so I assume that is the max.

[zkyzork]

Originally Posted by JCB

zkyork - are you trying to change the setting offline? Your app has to be connected to the JB4 when making configuration changes. Don't know of anything else that would cause the setting not to save.

I changed it while it's connected to JB4 with the car running. I also updated the firmware twice already just to make sure. The only thing I can think of is my phone might be too old if no one else running into this issue.

[roshg]

Originally Posted by JCB

My trims never go above 44 so I assume that is the max.

Thanks! if it stays at 44 for a while in the logs, does that mean my car has maxed out as much fuel as it can put in?