SUPRA ULTIMATE JB4 GUIDE AND LOG REVIEW (V1)

[ColonelAdama]

Here's a tip for MT cars:

Key is to keep ECU_PSI under DME_BT by 2-3 psi. Sometimes you may see an unexplained dip in DME_BT. This indicates that the FF curve is too high at the given RPM before the DME_BT dip.

In this case, I dropped duty bias at 4500 by 2, and dropped duty bias at 5000 by 1.

MT cars HATE cylinder-overfill. Any higher boost than was expected is going to make the car unhappy and drop boost targets. This part is really what makes tuning them so tricky.

Changing the JB4 boost targets also alters the FF curve, so it is best to just go additive mode and stick with the same targets and FF-value. That leaves just duty bias as a variable to adjust and smooth things out.

Duty bias used here are similar to any other catless Supra, however FF is set to 12. Everything else is standard settings on the MT firmware.

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[Shanki]

@ColonelAdama
Would you please take a look at my log with map4 with 93 octane. Don't really have any mod, just CAI. Anything I could do to improve it? Thanks!

 

[ColonelAdama]

@ColonelAdama
Would you please take a look at my log with map4 with 93 octane. Don't really have any mod, just CAI. Anything I could do to improve it? Thanks!

Sure, Post datazap here or PM me

 

[Shanki]

Thanks, here is the log https://datazap.me/u/colnlo/log-1686549343?log=0&data=1-4
Forgot to post it earlier.

 

[ColonelAdama]

Thanks, here is the log https://datazap.me/u/colnlo/log-1686549343?log=0&data=1-4
Forgot to post it earlier.

that is map 6, but i saw your map 4 on datazap too. car is requesting too high of targets, try dropping ff to 40 and letting it learn up. keep bit 1 off(default)

 

[Shanki]

that is map 6, but i saw your map 4 on datazap too. car is requesting too high of targets, try dropping ff to 40 and letting it learn up. keep bit 1 off(default)

Thank you for the quick reply. Will adjust it and see how it goes!

 

[Danisael]

Hi, just started trying to understand logs and tuning my JB4. Please share any feedback you may have on this log. My current concern is to find out if its normal to see 25.5 afr when coasting (gas pedal not pressed and car is moving on its own decelerating). I also notice that I need Wastegate tuning as my throttle is all over the place.I track my 2023 GR Supra. On track i use an ethanol blend of 25 and also use water meth for cooling intake air. I haven't had any issues but I have mostly used map 2. Have tried map 4 but the rear gets loose, its a slow track. playing now with reducing boost in third gear to keep confidence when applying power coming out of corners. Than you Colonel for the notes that started this thread.

https://datazap.me/u/danisael/first-logs?log=0&data=1-4

 

[ColonelAdama]

Hi, just started trying to understand logs and tuning my JB4. Please share any feedback you may have on this log. My current concern is to find out if its normal to see 25.5 afr when coasting (gas pedal not pressed and car is moving on its own decelerating). I also notice that I need Wastegate tuning as my throttle is all over the place.I track my 2023 GR Supra. On track i use an ethanol blend of 25 and also use water meth for cooling intake air. I haven't had any issues but I have mostly used map 2. Have tried map 4 but the rear gets loose, its a slow track. playing now with reducing boost in third gear to keep confidence when applying power coming out of corners. Than you Colonel for the notes that started this thread.

https://datazap.me/u/danisael/first-logs?log=0&data=1-4

Looks pretty good still. Try dropping FF to 40 and try again to see if throttle closures clean up.

Boost by gear will definitely help with your traction issues, you'll just have to keep playing with it. I personally use 2 psi redux in 1st and 1 psi redux in 2nd.

High AFR off throttle is normal, car isn't injecting any fuel while coasting.

 

[Cmant97]

Hey everyone recently got a jb4 off another supra owner I know for my 23 automatic. Got it installed updated and defaulted the settings and did a log in third gear and was hoping if someone could check it out real quick and see if it looks good would be greatly appreciated. datazap.me | cmant97 | 23 Supra 3/26/24

 

[ColonelAdama]

Hey everyone recently got a jb4 off another supra owner I know for my 23 automatic. Got it installed updated and defaulted the settings and did a log in third gear and was hoping if someone could check it out real quick and see if it looks good would be greatly appreciated. datazap.me | cmant97 | 23 Supra 3/26/24

Not bad. Drop FF to 45 and see if that cleans up throttle at all.

 

[Cmant97]

Not bad. Drop FF to 45 and see if that cleans up throttle at all.

Okay i will change tomorrow and get another log thanks for looking at it! i have an armaspeed intake and armytrix catless dp btw. second log i did datazap.me | cmant97 | supra 2

 

[Cmant97]

Not bad. Drop FF to 45 and see if that cleans up throttle at all.

datazap.me | cmant97 | supra ff 45 pulls from this morning. middle one had traction control on so it wonky looking. throttle still seems all over the place after changing the ff/wastegate adaptation option from 50 to 45. I'm also running wastegate bias at the default 50 for everything should i try the settings listed for high flow dp's in your guide?

 

[ColonelAdama]

I'm also running wastegate bias at the default 50 for everything should i try the settings listed for high flow dp's in your guide?

Yes, that was going to be my next suggestion. You can probably drop FF to 40 as well when you change the duty biases.

Most catless cars I've reviewed have FF between 35-40 and similar duty bias to what my guide shows

 

[Cmant97]

Yes, that was going to be my next suggestion. You can probably drop FF to 40 as well when you change the duty biases.

Most catless cars I've reviewed have FF between 35-40 and similar duty bias to what my guide shows

I’ve made those changes this is what my settings look like now will try and get a few pulls after work

 

[ColonelAdama]

I’ve made those changes this is what my settings look like now will try and get a few pulls after work

Looks good to me! You can send me the logs in PM so I can keep better track of your revisions.

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