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obiwanshinobi87 obiwanshinobi87 is offline
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Default JB4 seems to give more boost in comfort mode than sport - 08-20-2018, 06:25 AM

Hi, I've got a 2016 340i with a JB4+Bluetooth Kit (latest firmware) and cold air intake, otherwise stock. I'm running Map 2 on 91 octane.

I've noticed in daily driving that when the car is in comfort mode and I floor it, the car actually kicks me into the back of the seat with its boost. When I switch to Sport mode, the steering and suspension tighten up as expected, but the motor seems to be a bit tamer. Definitely not as hard of an acceleration. It's completely the opposite of what I'd expect.

Anyone else notice this, or can explain why this might be?
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Terry @ BMS's Avatar
Terry @ BMS Terry @ BMS is offline
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Default 08-20-2018, 07:34 AM

The sport vs. comfort mode only control the rate of power as a function of pedal input, not the peak power target. So at partial throttle they will differ, at full throttle match up, as we confirmed on the dyno.


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obiwanshinobi87 obiwanshinobi87 is offline
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Default 08-20-2018, 08:42 AM

Thanks Terry.

I've read that before, and assumed it to be the case until recently. I've noticed that I don't really even have to floor it to get a good kick out of the car in comfort mode, whereas the sport mode seems to be more linear in the power build up regardless of if I floor it or not.

Is this the car's ECU adapting to my driving habits, or does the JB4 completely override this aspect (I spend 99% driving in comfort)? Any chance you guys will offer an option to adjust steering feedback through the JB4 in the future?
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Terry @ BMS's Avatar
Terry @ BMS Terry @ BMS is offline
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Default 08-20-2018, 09:01 AM

The JB4 maps based on various parameters, including pedal input, and factory boost target. But the best way to solve mysteries like this is with the JB4 logging feature. Record and evaluate runs from different modes to spot the technical differences.

On the steering I haven't look at it, but I don't think it's something we'd want to hijack for safety concerns.


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It is the sole responsibility of the purchaser and installer of any BMS part to employ the correct installation techniques required to ensure the proper operation of BMS parts, and BMS disclaims any and all liability for any part failure due to improper installation or use. It is the sole responsibility of the customer to verify that the use of their vehicle and items purchased comply with federal, state and local regulations. BMS claims no legal federal, state or local certification concerning pollution controlled motor vehicles or mandated emissions requirements. BMS products labeled for use only in competition racing vehicles may only be used on competition racing vehicles operated exclusively on a closed course in conjunction with a sanctioned racing event, in accordance with all federal and state laws, and may never be operated on public roads/highways. Please click here for more information on legal requirements related to use of BMS parts.
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LessIsMore's Avatar
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Default 08-20-2018, 09:03 AM

See if times are any different between comfort and sport using dragy or something.
Difference might just be all in your perception due to BMW trans tuning shift differences?

I don't believe any JB4 overrides the OEM 'learning' by either DME or TCU.


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Turboh Turboh is offline
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Default 08-28-2018, 07:34 PM

Seat of the pants evaluation is tricky and depends on how you feel as well as numerous engine variables. I am finding that the only way to judge how fast you car is, is to log the runs as described in this thread, and then:

1. Import the logs in excel
2. Graph rpm vs time
3. Set the trend line for the resulting curve, it is linear
4. Ask excel to display the equation for the line and then look at the slope portion of that equation. It shows the rate of rpm change per unit time. This is directly related to your acceleration.
5. The higher the number, or slope, the higher the acceleration. Mine range from mid 40ís for map 4 to mid 50ís for all othe addive and absolute maps. Interestingly, high boost maps say 17 absolute on map 6 are not better than map 2. The difference is timing.....mainly.

I am finding that it helps me decide which map and map setting is best. It eliminated seat of the pants feelings. Much more objective.

Results so far have been that map2 is very good compared to all other absolute and additive maps. Timing is very important and boost numbers are deceptive.



2017 340iX with M track handling package, 6 speed manual, BMS intake, and JB4 piggyback; EWG and FP wires; 93 octane; and fun with Honda S2000; Ninja Z1000.
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JorgeIII JorgeIII is offline
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Default 09-17-2018, 07:23 AM

Quote:
Originally Posted by Terry @ BMS
The sport vs. comfort mode only control the rate of power as a function of pedal input, not the peak power target. So at partial throttle they will differ, at full throttle match up, as we confirmed on the dyno.
Hello Terry. That might not be the case, at least for the B48M engine in the 320i.
Here you have some logs to compare at full throttle. Stock 320i map 4.

In comfort it starts with about 5 psi @ 2000rpm, climbs to 9-10 psi at 5000 rpm and cames back to 7 psi till red line. In sport it starts at 7 psi, climbs to 9-10 psi at 5000 and stays there till redline.

It's a different boost/rpm curve shape.



Jorge
Attached Files
File Type: csv comfort map4.csv (12.0 KB, 22 views)
File Type: csv sport map4.csv (17.4 KB, 19 views)
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OzBMR OzBMR is offline
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Default 09-18-2018, 02:43 AM

I've found that absolutely stock standard B58 in M140i Comfort mode is 2 - 3 PSI lower peak boost than in Sport or Sport+, but timing advance is more in Comfort and less in Sport or Sport+ using 98 RON fuel (93 octane USA). I have done dozens of runs logging comparing all settings, generally in 3rd gear from around 2000 RPM and wide open throtle, manual shifting with ZF8, plus drag strip launches.

At the drag strip I found that Comfort mode gave ever so slightly the best 60 ft time, probably due to lower boost and less wheel spin and associated slip and/or traction control. On the street, in just 3rd gear pulls I got higher peak power and torque readings in Comfort in 3rd gear, which I put down to more timing, less boost and more grip down low.

Fastest time and best MPH at the drag strip has always been in Sport mode, probably due to having a higher grip surface and better mapping for drivetrain, gear change times etc.

Maybe the feeling of going faster when the OP floors it is a result of more/optimal traction from less boost?


Australian 2016 M140i LCI Mineral Grey ZF8 Speed Auto
12.4 @114.6 mph with 2.06 sec 60ft
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jbourne jbourne is offline
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Default 09-26-2018, 07:53 PM

subscribed, i want to know more about this as well..
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