SUPRA ULTIMATE B58 JB4 GUIDE AND LOG REVIEW (V1)

[ColonelAdama]

Love what you’re doing Colonel ?! Is it worth doing some 3rd or 4th gear pulls when not on track? Sorry if it seems like I’ve asked this ? times (I only have 4-5x ?). Temps are in the 90s & hot as schweaty balls. I could turn the JB4 on in MAP2 and record some hard pulls, TC off, in manual mode, and hit it going 30-100mph?

I do have a track recording when my wife was driving (not as hard) that I can send ya too. Good thing it doesn’t record me yelling full throttle while we were doing the pulls ?. It didn’t go out for her btw. Like it does almost instantly, 5-10 minutes in every time for me. Sometimes sooner. Hence why I just leave it off on track.

Thanks again amigo! I still haven’t made it up to TBR yet. When I do, will definitely give you a holler.

What fuel are you running? Send me a PM of map 1 (FF=30) if on 93

Yes almost everyone street tunes. 3rd gear pulls are fine to avoid "straight to jail" speeding lol. 2500-6500 rpm flat out

You're overdue on getting that tune fixed! We can get you a mild map for the track, though even map 1 may be fine.

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[5150.MKV]

As promised my first log on Map 1
MT
2 Gallons of E
Stock downpipe
CAI
Catback exhaust
I did buy this used so I set all the settings back to default so might have messed something up but didn’t feel too special off this pull!

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

 

[ColonelAdama]

https://datazap.me/u/jackskelly/e40-log?log=0&data=1-4

everything looks fine to me

 

[ColonelAdama]

As promised my first log on Map 1
MT
2 Gallons of E
Stock downpipe
CAI
Catback exhaust
I did buy this used so I set all the settings back to default so might have messed something up but didn’t feel too special off this pull!

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

update to v28 firmware or newer and make sure the BEF bit isnt checked under options (bit 6). Map 1 again

 

[FLtrackdays]

What fuel are you running? Send me a PM of map 1 (FF=30) if on 93

Yes almost everyone street tunes. 3rd gear pulls are fine to avoid "straight to jail" speeding lol. 2500-6500 rpm flat out

You're overdue on getting that tune fixed! We can get you a mild map for the track, though even map 1 may be fine.

93 O and will do Colonel ?

You’re right my Map6 is a street/drag tune, since I didn’t specify at the time or thought it mattered ??‍. The JB4 was a gift in exchange for my OEM downpipe - when I 1st bought the car and my catless dp. I always cook the cats ? (on my previous cars), so to speak, so I put that on 1st before I went tracking.

I’ll do a 3rd gear pull with TC off, on my crappy street tires, at 2500-6500 rpms flat out and go from there. I might need to get my real tires back on the car to do it properly. Thx again amigo!!

 

[ColonelAdama]

93 O and will do Colonel ?

You’re right my Map6 is a street/drag tune, since I didn’t specify at the time or thought it mattered ??‍. The JB4 was a gift in exchange for my OEM downpipe - when I 1st bought the car and my catless dp. I always cook the cats ? (on my previous cars), so to speak, so I put that on 1st before I went tracking.

I’ll do a 3rd gear pull with TC off, on my crappy street tires, at 2500-6500 rpms flat out and go from there. I might need to get my real tires back on the car to do it properly. Thx again amigo!!

Sounds good! Try to use V24 firmware or newer.

 

[5150.MKV]

update to v28 firmware or newer and make sure the BEF bit isnt checked under options (bit 6). Map 1 again

Revised
https://datazap.me/u/samedice/log-2?log=0&data=1-4

 

[ColonelAdama]

Revised
https://datazap.me/u/samedice/log-2?log=0&data=1-4

Looks good, enjoy.

 

[ColonelAdama]

https://datazap.me/u/coloneladama/l...ta=1-2-3-4-11-13-15-25-26-27-28-29&zoom=19-73

Good example of proper tuning on MT - my car today.

Here's a useful tip if you're struggling with throttle closures- Keep dropping duty/FF where you see calc_tq exceed 48. You can see mine is perfectly smooth thru the usual troublesome mid range since I keep calc_tq under 47. Make sure to use V28 firmware or newer.

You will typically see calc_tq spike towards 50 before you get a closure.

I can't say for sure why it works but I figure the injection monitoring BS doesn't kick in until you get near the dme load limit (or in JB4 terms that would be calc_tq at 50)

 

[ColonelAdama]

Not all 93 (or premium) fuel is created equally.

Here's the strongest pump gas 93 (shell) JB4 car I've been finishing up at 20-21 psi. Easily a 440whp/500wtq car.
https://datazap.me/u/coloneladama/log-1749237553?log=1&data=1-2-11-25-26-27-28-29-34&zoom=52-90

This is why logging is so important. My car won't even run Map 1 this cleanly on 93 around here.

The BMS map suggestions are rarely accurate in my experience.

Cali 91 on Map 1 will be rough. Consider not tuning your car unless you have ethanol.
Proper 91 on Map 1 will be ok.
93 on Map 1 will be good.
93 on Map 2 will be iffy (usually not good enough). 2 gal E85 in the mix guarantees a strong Map 2.
Rare cases where Map 3 works fine with E30, but its really more for Gen 1 b58 or B48s handle it pretty well. M40i engines can't handle it as they already run so much boost factory.

Map 4 or 5 on P158 firmware are strictly to be used with E30-E40 with FOL control ONLY (fp upgrade).

In this case, this owner got a Map 6 (similar to Map 3) out of his 93 fuel.


His testimonial is that his wife's JB4 tuned X4 is now quicker 60-120 kph than his M240 on MHD stage 2. (2.95s vs 3.12s) JB4 car in worse DA and about 500 lbs heavier. Definitely unusual for JB4 to be so much quicker than MHD on pump gas!! Shows that OTS is usually conservative for the given fuel, and a custom JB4 map can match it or beat it if the fuel is exceptional.

 

[FLtrackdays]

Not all 93 (or premium) fuel is created equally.

With that being said, are there any fuel additives you recommend for us 93 octane folks? Most of us just use the closest gas station to the track and fill our cars and jugs with it (Mobile or Wawa).

Going back, my RX8 used a 2 stroke oil additive in the fuel for longevity and performance. I know, it’s a rotary and that’s an extreme case. But it did make a difference.

Appreciate you amigo & thx for all the helpful info!!

 

[ColonelAdama]

With that being said, are there any fuel additives you recommend for us 93 octane folks? Most of us just use the closest gas station to the track and fill our cars and jugs with it (Mobile or Wawa).

Going back, my RX8 used a 2 stroke oil additive in the fuel for longevity and performance. I know, it’s a rotary and that’s an extreme case. But it did make a difference.

Appreciate you amigo & thx for all the helpful info!!

I know people have used boostane before. I have heard too much can foul plugs or o2 sensors, can't really remember.

I'd stock up on a bit of ethanol instead if you can get your hands on it, or even consider water meth injection.

 

[ColonelAdama]

Gave the initial post a little update for 2025 regarding new P158 firmware , fuel pressure control upgrade, wastegate tuning changes and recommended settings. JB4 has never been more capable for Supras than now, even MTs.

 

[ColonelAdama]

Is it normal for trim to be in the high 40s while under 4k rpm 3rd hear 100% throttle and quickly dropping towards 40 trim and redline? Im on custom map6 e20

Completely normal. Try to keep trims under 45 though, reduce E or boost in the affected RPM range

I recommend a tapered boost curve for E blend cars. (like an E20-E25 example here)

map6_15	map6_20	map6_25	map6_30	map6_35	map6_40	map6_45	map6_50	map6_55	map6_60	map6_65	map6_70
1.8​	2.3​	2.8​	3.3​	3.8​	4.3​	4.8​	5.3​	5.3​	4.3​	3.3​	2.3​

 

[ColonelAdama]

Pretty similar to mine +- 0.2.
Mine @55 5
@60 4.5
@65 4
@70 3.5
2.2 gallons of e85 should be around E25. Trim never goes pass 45-46
Peak psi is 18.5-19psi. I used to see up to 20.5.

that is perfectly fine, boost goes up with IATs (and timing down)

FP upgrade is a good buy since you can run like 4 gallons E and up to +7psi targets or higher

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