JB4 and facelift C43
Thread Starter
Senior Member
Joined: Nov 2016
Posts: 352
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From: in a van down by the river...
2020 C43 sedan(hers), 2021 Porsche 992 TurboS(his)
JB4 and facelift C43
Is anyone with a 2019 or 2020 C43 using an off the shelf JB4 piggyback system?
What are your impressions?
What are your impressions?
Thread Starter
Senior Member
Joined: Nov 2016
Posts: 352
Likes: 48
From: in a van down by the river...
2020 C43 sedan(hers), 2021 Porsche 992 TurboS(his)
I'm curious why the JB4 system with wireless BT connection should even need a separate BCM, aside from the marketing up sell?
Why could they not just include tune maps that have added boost+?
Why could they not just include tune maps that have added boost+?
Member
Joined: Mar 2020
Posts: 199
Likes: 75
Acura TL-SH, among others
The issue is in the WGDC in the facelift cars. Despite the JB4 attempting to deliver more boost, actual boost was falling off. Trying to add more wouldn't have helped, but more importantly, if it DID work, you'd blow your motor. Rather than band-aid the issue, BMS asks people to add a BCM to get proper control over requested boost. You don't have to do it, you'll still get gains, but if you want the same gains as pre-facelift, it takes the BCM.
Thread Starter
Senior Member
Joined: Nov 2016
Posts: 352
Likes: 48
From: in a van down by the river...
2020 C43 sedan(hers), 2021 Porsche 992 TurboS(his)
The issue is in the WGDC in the facelift cars. Despite the JB4 attempting to deliver more boost, actual boost was falling off. Trying to add more wouldn't have helped, but more importantly, if it DID work, you'd blow your motor. Rather than band-aid the issue, BMS asks people to add a BCM to get proper control over requested boost. You don't have to do it, you'll still get gains, but if you want the same gains as pre-facelift, it takes the BCM.
Member
Joined: Mar 2020
Posts: 199
Likes: 75
Acura TL-SH, among others
Yes and no basically. BMS followed the issue and offered a solution. It does suck that facelifts can't get he same gains with just the JB4, despite having larger compressors and a higher initial HP, but it's easy to fix.
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C190
Arguably the facelift can’t get the same gains even with a tune.
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2018 C63 Sedan
We're not thrilled the 2019+ models need extra tuning hardware to approach the pre-facelift models either but little we can do about it. We just tune the cars as they come. Blame Mercedes. 
Making the extra BCM add ons is a pain in the *** and we sell it close to our production cost.
Making the extra BCM add ons is a pain in the *** and we sell it close to our production cost. 
Thread Starter
Senior Member
Joined: Nov 2016
Posts: 352
Likes: 48
From: in a van down by the river...
2020 C43 sedan(hers), 2021 Porsche 992 TurboS(his)
We're not thrilled the 2019+ models need extra tuning hardware to approach the pre-facelift models either but little we can do about it. We just tune the cars as they come. Blame Mercedes. Making the extra BCM add ons is a pain in the *** and we sell it close to our production cost.
Making the extra BCM add ons is a pain in the *** and we sell it close to our production cost.I was told, by one of your Canadian re-sellers (Mike) that you (Terry?) had to set it up for a 2020. Is this accurate?
