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Irishace Irishace is offline
ElevenPointFive
 
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Default Launch Control & Boost Capping - 07-29-2015, 07:57 AM

Terry et all, really need your thoughts on this as well as confirmation on the boost capping functionality for the S55 JB4. I am current running map 2 with ER *** and 94 pump gas. I am having one hell of a time successfully launching this car. If I use LC it just turns into a gian smoke show (fun and very cool) but its not the desired effect I want as I want a smooth transition of getting the power down.

I just want to confirm that I am using the boost capping by gear functionality correct. I currently have boost cap set to 15psi in 1st and 18psi in second. In the fields am I correct in inputting the value that I want to cap the boost at for each gear? Meaning, 15 psi in 1st means that 1st gear will not exceed 15psi?

If this is indeed correct, I am thinking now of capping boost to 10-12 psi in 1st and potentially running my tire pressure at 30psi. I just want to practice before I take a run at the drag strip. As it stands now I am totally incompetent at launching this car, great at burnouts, not so much at launch.

HELP!


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2008 E90 335xi - AT - TSM
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Mike@N54Tuning.com Mike@N54Tuning.com is offline
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Default 07-29-2015, 08:14 AM

Terry will have to chime in but you enter the max boost value you want per gear (1-3), but I am not sure the JB4 can cap boost below stock target. Terry would have to confirm.

Mike


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Irishace Irishace is offline
ElevenPointFive
 
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Default 07-29-2015, 11:50 AM

T?


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Cobb Stage 1

2008 E90 335xi - AT - TSM
MHD Stage 2+ ~ BMS Intake ~ AMS FMIC ~ CPE
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Terry @ BMS Terry @ BMS is offline
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Default 07-29-2015, 01:16 PM

With obdii firmware it's a cap but it can't be set below the oem boost target.

If you need addl help let's see a log of the launching to see if a having stands out.


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ElevenPointFive
 
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Default 07-29-2015, 05:02 PM

Ok will do some logging this weekend.


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2008 E90 335xi - AT - TSM
MHD Stage 2+ ~ BMS Intake ~ AMS FMIC ~ CPE
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PikkaGTR PikkaGTR is offline
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Default 08-05-2015, 12:24 AM

sorry to jack your thread, but i just want to confirm the boost limiting function of the obd2 JB4 for the S55.
Is it changed to value set is the maximum boost and no longer the amount reduced by gear?
Also, how do I know how much boost is set at looking at the Tach? is it still 2x the RPM value as in 8k is capped to 16 psi?
TIA
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Juiced46 Juiced46 is offline
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Default 08-09-2015, 06:28 AM

Do not get too discouraged that you are just doing a big smoke show on the street trying launch control. @ the track conditions are much much different. On the street you are launching on an unprepped surface.

If it were me. I would leave 1-3rd boost by gear set to zero for track use. Launch the car @ the lowest possible RPM @ the track and move up on the next pass and so on. Also adjusting tire pressures will help depending on track prep and what type of tires you will be using.


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F8X_m3 F8X_m3 is offline
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Default 08-25-2015, 11:48 AM

Maybe set launch to lowest possible RPM and also try launch in Efficient Mode instead of Sport Plus, this can be done as I've launch it in efficient and didn't realize i was in Sport Plus , also keep your foot to the floor (only do this in a wide open street in case you get to sideways ) launch control has its own TC and if you let off the slightest to feather it seems I am spin more .
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Default 08-27-2015, 12:14 PM

Thanks for the tips. Will give them a shot.


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2008 E90 335xi - AT - TSM
MHD Stage 2+ ~ BMS Intake ~ AMS FMIC ~ CPE
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