PxcesYT

I wanted to know if there are people who have a JB4 on a 2020 c43. If you guys have just that can you guys please send me some 0-60 tests just so I知 sure I知 getting around the right numbers.

BMS

Getting the launch perfected makes the most difference on short 0-60mph times. If trying to evaluate tuning performance 1/4mile trap speed is a better measurement, or 60-130.

David Hudak

Jb4 map 2 w/BCM 0-60

c43PDX

I though BCM wasn't necessary for Map2? Have you ran without it and feel a difference? I was told BCM not necessary until using blended fuel.

David Hudak

Maybe your referring to the green fuel wire that is not necessary until blending? I guess you can say BCM isnt NECESSARY, but if you want the most power out of facelift models than inwpuld get it.im sure BMS will chime in on this.

PxcesYT

BMS told me to get a BCM because it would make the power better or allow for better response with the 2019-2020 models. However according to the app I知 making 0-60 time with Map 2 in 4.4 seconds. That doesn稚 sound right. The warm temperature could also make less cool air go to the engine therefore making 0-60 way slower.

mike3082

I was told the BCM is "optional" and really only intended if you plan on running higher boost targets i.e. ethanol blend etc by BMS. If I only intend to run pump gas and just the JB4 on a 2020 C43, can anyone tell me ball park numbers that we should be seeing?

Howyalivin

If you have a facelift car and you want to get the same level of gain as a PFL, you need the BCM. Due to changes in the WGDC, the car won't hold the boost that the JB4 is trying to dial in. That's regardless of meth or any other changes. If you have a 2019 or 2020, do yourself a favor and get the BCM so that you can hold boost levels that PFL cars do with the same mods.

mike3082

Ok awesome this was the response I was looking for!

c43PDX

still confused, so beyond Map3, BCM is needed is what I was told. So are there benefits to having the BCM even at MAP 1 or 2?

PxcesYT

I知 confused myself someone told me I need more things to run map 2 itself.

Howyalivin

If your car was made before 2019, all that you need is 93+ octane to run Map 2. Nothing else.
If your car is a 2019 or 2020, you can still run map 2 on 93+, but your gains won't be the same due to boost falling off. You'll have to also buy BMS's BCM so that you hold the boost levels that the JB4 is requesting.

Here's a summary of each map and the requirements for them.

JB4 Map Guide as of v6 firmware:
Map 0: Disables tuner
Map 1: Up to 4psi over stock peak, suitable for all 91 octane+ fuels
Map 2: Up to 5psi over stock peak, suggested for 93octane+
Map 3: Up to 5.5psi over stock peak, slightly more aggressive version of map2
Map 4: Up to 6psi over stock peak, suggested for E30+ or unleaded race gas mixtures
Map 5: Up to 7psi over stock peak, holding more boost to redline, suggested for E30+ or unleaded race gas mixtures
Map 6: User definable map, boost over stock entered on user adjustment page
Map 7: WMI (water/meth injection) progressive map for BMS FSB integration

Howyalivin

Sorry, I just noticed your comment. Here's a direct quote from BMS on an earlier thread:

mike3082

Thanks for the clarification. I sure hope BMS is working on a remedy besides "spend more money and buy a BCM". If you own a Facelift model i.e. 2019+, you have to spend an EXTRA $200 to accomplish the same thing as Pre-facelift models.

That's extremely discouraging for us with newer models. Why should we have to spend extra money to accomplish the same thing as earlier models?

PxcesYT

Are downpipes needed to run map 2 or map 3 since I already have bcm you would think you壇 notice a difference from 385hp to the acclaimed 460hp.

Howyalivin

It does suck that FL models have to use a BCM to get the same power, but it's a physical component issue that is Mercedes fault, not BMS's, and probably by intent. Unfortunately BMS can't simply code around a wastegate issue. Here's a good article that explains the function of the wastegate and its duty cycle, that should make it apparent why the JB4 can't be made to fix it, but the BCM can. Consider, that even with the JB4 plus BCM, you're still spending far less than a full tune, with comparable performance, and giving yourself a much better chance to avoid warranty coverage issues.

https://stratifiedauto.com/blog/what...-turbo-setups/

Howyalivin

No, you don't need DPs. If you aren't getting the performance you expect, meaning quarter miles that are between 6 tenths and 9 tenths quicker on map 2, you should reach out to BMS and start looking at your logs. If you have a Dragy, run a few pulls in map 0, then a few on map 2, and check the difference in times. For comparison, at decent altitudes and temps, a stock pre-facelift C43 should be able to run 12.8 to 13.0 in the quarter. On map 2, they've been able to get to 11.9 on the fastest ones, to about 12.2 on the low end. The facelift cars are as much as 2 tenths faster stock, but they don't get the same uplift from ECU side mods, because they are already running slightly higher boost.

c43PDX

that is a great read. I have heard FL has a bigger turbo than the PFL, so do we have more efficiency top end compared to the PFL then? Or at what whp do we need to change the turbo for more top end power? I personally like power all the way to the top instead of the OEM style of strong down low and falls on its face past 4k rpm..

gordotre

I have been told that the 2019s have been limited by many of the ECU settings now also being controlled by the CPC (Central Powertrain Control). I have already have EC V4 + DPs + E30 tune and had a new (customized) CPC/TCU upgrade done and certainly feels more responsive. I do not know if I can hold more boost yet or not until I do some logs and have a more agressive tune done that would give me more boost. I currently do not feel an awesome improvement yet. Based on this no matter what I do I will not see improvement. Is this correct and what does the BCM do that cannot be done through a tune?
I am admittedly not anything close to very knowledgeable and just basing all this on what I have been told by others.

Howyalivin

There aren't a lot of people that go through the effort to add larger turbos. There was one project that was moving down that road, then the guy dropped off the radar. I've seen one dragy run shown with 100-200 km times, that had aftermarket turbos. There's another one that is working towards it, but otherwise it's more like Bigfoot sightings. Most people that want significantly more power just move to the C63. If AWD is a requirement, the E63 would work too.

If you plan to run aftermarket turbos, there are a lot of other things that need to change, so cost quickly becomes an issue. The simplest is fueling. The stock fuel pump isn't going to work with an aftermarket turbo setup. You should also change the intercooler. There's been plenty of talk that the stock rods aren't strong enough for an aftermarket turbo build either, so you would have to have custom ones made. There's an older thread where a person has all the specs for his listed. If you search you should be able to find it, but there were a sizeable number of changes that had to be made to accommodate the new turbos.

The fastest I have heard of a stock turbo setup running is 11.1's, without DP I believe. Not sure if the person had meth, but definitely used race gas, a JB4, and ported stock turbos. They also had one of the fastest cars on this site before doing that. I can't say the person themselves came on to talk about it. We heard about it from someone else that was at the track when it happened. I can't recall if the timeslip was posted.

Howyalivin

I was talking about for JB4 cars. If you start tuning the ECU, you have control over a lot more features than a piggyback can access. The piggyback is essentially just lying to the stock ECU about what the sensor inputs are so that it makes the changes, according to its stock tables. It's why, once you remove a JB4, there isn't evidence of out of range values that can be recorded and accessed by the dealer. I'm not going to talk about ways that a manufacturer could identify that a piggyback had been on a car, let them think up their own methods.

Ramsino

If I install the JB4 and use any ethanol blends, I'm sure the dealers can just siphon a bit of fuel out and do a quick test or even smell that I had E85 mixed in there...which would certainly mean that I had some sort of tune in the car and just like that, warranty is voided.

C43pleasehelp

what if I知 in California and I want to run e30 ? Can I still use map 2? We don稚 have 93 octane in cali but I though if u have a e30 mix u should be fine is that true ? Can someone explain I知 confused

Howyalivin

If you are running E30, you're fine because it's 94 octane equivalent. If you want to use E85, a few gallons worth mixed with 91 octane, there are calculators for that. Here's one, with two different calculation methods, one giving effective octane rating.

https://www.morepowertuning.com/emix

Howyalivin

As a cautionary note, don't run much over about E30. The fuel pumps in these cars weren't meant for it. For higher boost levels, find yourself some race fuel or Boostane.