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Discussion Starter · #1 ·
Hello everyone, I recently installed a JB4 and been playing around with setting and logs to figure out the best settings for my car.
I'm on 91 octane (California), so far getting good results with map1 while map2 is borderline with timings.

As I want to be more on the conservative side, I was trying to create +3psi map6s but didn't get better results than the default map1.

Was thinking that BMS already did some testing and figured out a solid map for +3psi - the JB1's default map.
Does anyone know what is the boost/rpm profile of the JB1 +3psi default map?
 

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Seems like BMS designed the stock maps around the non RS models. They are pretty well dialed in and I have not been able to create a Map 6 that feels any better. I think map 6 is best used for RS owners who want to add something less than map 1 boost to their stock setup OR the guys really pushing these cars to the limit and need targets beyond the Map 5 plus 7psi peak.

As DDNSpider indicates, you can log a pull in the stock maps, then review the target PSI. Its common misconception that the stock maps just add a flat boost to the ECU target. They actually all taper at higher RPM range and peak in the mid range through 5500 RPM or so.
 

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Discussion Starter · #6 ·

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Discussion Starter · #7 ·
If you log "target" you'll see what BMS has their different map boost curves set to.
I did with my JB4, but was wondering how is JB1's +3psi profile looks like.

JB4 map 1 seems to be:
RPM​
Boost​
1500​
3​
2000​
3.5​
2500​
4​
3000​
4​
3500​
4​
4000​
4​
4500​
4​
5000​
4​
5500​
3.5​
6000​
3​
6500​
2.5​
7000​
2​
 

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Discussion Starter · #9 ·
Seems like BMS designed the stock maps around the non RS models. They are pretty well dialed in and I have not been able to create a Map 6 that feels any better. I think map 6 is best used for RS owners who want to add something less than map 1 boost to their stock setup OR the guys really pushing these cars to the limit and need targets beyond the Map 5 plus 7psi peak.

As DDNSpider indicates, you can log a pull in the stock maps, then review the target PSI. Its common misconception that the stock maps just add a flat boost to the ECU target. They actually all taper at higher RPM range and peak in the mid range through 5500 RPM or so.
Yes, I cannot create a better +4psi or +3psi map that feels and log better than map1.
Was wondering how the JB1 +3psi looks like...

Its pretty quiet on our N54 site! The BMS guys don't always answer people looking for guidance or review of their logs. They have been a bit more responsive of late, but the answers tend to be very simplistic and nearly always push the fuel wires!
Agreed.
 

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Discussion Starter · #10 ·
I was under the impression the jb1 was flat boost.
If this is the case I will give a shot for +3psi flat boost map, although it's a little much to have +3psi at 6000-7000rpm.
 

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If this is the case I will give a shot for +3psi flat boost map, although it's a little much to have +3psi at 6000-7000rpm.
Not if you're not a red sport.
 

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Jessie, if you have JB4, no need to think about anything JB1. If you are stuck at a lower JB4 map it is likely because you have poor fuel/octane. Unfortunately you are in Cali, so you may be unable to run the higher boost levels unless you can mix in some E-rich fuel with the 91 available to you.
 

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Discussion Starter · #13 ·
Do you think running map1 daily with 91 octane will be safe?
Planning to keep the car for a couple of years.

map1 log:
Light Rectangle Slope Font Line
 

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You don't need a "daily driver" map unless you are planning to run upgraded fuel sometimes. In that case, you would have a map for the normal pump gas, and a map for the "race" fuel. If you are just planning on filling with the best gas available (in your case Cali 91 octane), than you should log until you find the optimal map for your fuel and then just keep it there. In everyday driving, the JB4 does virtually nothing. It only adds boost under heavy throttle. Everyday driving under light throttle does not change.

The log you posted looks fine. The Ign1 field is an indicator of what your car is doing to advance timing. If you see big/sudden drops in this value, it likely indicates "Knock" due to pre-ignition due to the fuel's octane. Yours looks normal to me, and I think you could even try moving up to map 2.

Key is to keep logging and reviewing. Even after you settle on a map (and purchase fuel consistently from the same, most reliable source) it is important to keep logging whenever you can. Even buying fuel from consistent sources you can see some variation in actual octane. If you get a bad tank of gas, you just need to take it easy until you can work it down and fill back up with good fuel. It doesn't happen often across the big brands, but you can get some inconsistency.

Over time if you are someone who pushes their car, you will learn the "feel" and sound of knock. Post back with your log if you want to try map 2 or higher. I or someone else will give you some feedback to make sure your still looking good.
 
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BMS stated somewhere that they were pretty much done with the VR30 because they felt it ran it's course. I believe this is due to a dwindling consumer base mostly.

Steve and Terry answer about 25 posts a day on avg across that site and have been for quite some time. Traffic has falling on that subforum but it's still the best place to go for information and archived posts.
 

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BMS stated somewhere that they were pretty much done with the VR30 because they felt it ran it's course. I believe this is due to a dwindling consumer base mostly.
Queue the Nissan Z ;)
 
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