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T2019Q50S T2019Q50S is offline
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Default JB4 adjustment during partial throttle - 08-08-2019, 11:37 AM

So Iím looking to add the JB4 capability and have read many of the threads.

I donít see any mention of how the JB4 handles/adjust partial throttle boost....?
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Default 08-09-2019, 10:47 AM

What are you trying to do exactly?


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Default 08-09-2019, 12:05 PM

When you drive, most of your time is spent in partial throttle acceleration. What does the system adjust during this phase? Most people donít drive at 100% throttle all the time. As the JB4 commands addition boost, if you add 4 additional psi, what does the system do during a partial throttle acceleration?

Just trying to get an idea on how drivability is effected.

A simple example for a discussion and not the actual parameters. If we have a stock maximum boost of 8 psi at 2500 rpms and we increase this by 4 psi using the JB4. The ďcommanded maximum boostĒ would be 12psi at 100% throttle. If you are at 50% throttle with a given load at 2500 rpms, stock might only request 4 psi (50% of 8) but with the added boost per the JB4, does this become 6 psi (50% of 12)?

Dose this help?
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importroller importroller is offline
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Default 09-19-2019, 02:11 PM

I was always thinking that the JB4 adjust the psi according to what the OEM is doing. SO whatever OEM does at partial throttle, the JB4 adds whatever PSI you have it set to on top of that, regardless if it's WOT or partial throttle. Or am I mistaken. I'm still learning how to read the datalogs
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Default 09-21-2019, 06:31 AM

You wouldnít want the JB4 to simply add the additional Commanded boost to the OEM value as that would cause surges. For example if you are accelerating at partial throttle, the OEM may only be commanding 3 psi and if the JB4 is adding 4 psi more that would then be 7 psi.

I get that everyone wants to see their total increase but most of the time driving isnít at WOT. To me this is where the debate would be on an ECU tune versus the JB4.

Just so it clear Iím not trying to debate the ECU tune, simply trying to understand at a high level how the JB4 adjusts partial throttle.
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Default 09-21-2019, 02:50 PM

Quote:
Originally Posted by T2019Q50S
So I’m looking to add the JB4 capability and have read many of the threads.

I don’t see any mention of how the JB4 handles/adjust partial throttle boost....?
The same way it does at full throttle. Boost added is as a function of pedal input. You'll get a lower effect at low throttle than at heavy throttle to keep things running smoothly.


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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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importroller importroller is offline
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Default 09-24-2019, 04:19 PM

Quote:
Originally Posted by T2019Q50S
You wouldnít want the JB4 to simply add the additional Commanded boost to the OEM value as that would cause surges. For example if you are accelerating at partial throttle, the OEM may only be commanding 3 psi and if the JB4 is adding 4 psi more that would then be 7 psi.

I get that everyone wants to see their total increase but most of the time driving isnít at WOT. To me this is where the debate would be on an ECU tune versus the JB4.

Just so it clear Iím not trying to debate the ECU tune, simply trying to understand at a high level how the JB4 adjusts partial throttle.
makes perfect sense when you stop and think about it.
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