I am still a bit confused about what load based boost scaling works for the 17-18 models but is not working for 19s, or even the c400 and c450. May be it is above my paygrade but a thorough explanation would be nice. Just asking out of curiosity.

 

I personally experience very little to no throttle closure ever since I started using the green wire for fuel sensor and set FOL to 50, I have noticed a significant gain in butt dyno with less throttle closure during shifts. Also the way the car seems to be shifting through the gears, feels way smoother to me. My dragy was dead when I went testing, so I couldn’t confirm actual numbers it but I will do it soon. Here are the logs:

 

munis, is yours a 2019 as well? I may not be an expert but your logs look way better. Post your dragy results when you can! Really interested to see how a 2019 performs properly with the JB4.

 

No mine is a 2017. My dragy results are already posted in the leaderboard.

 

Awesome performance results!

Am I correct to say that the 2017 in stock form according to factory spec produces max torque as early as 1900rpm, while the 2019 max torque starts at 2500rpm? Similar to the outgoing E43?

 

 

Those graphs don't look right. There's something wrong for the 2019 at the lower rpms, like some form of slip or intervention. I doubt that it only makes 150lbft up to 2500rpm, and its actually decreasing causing flat horsepower curve up to 2500rpm. So it's supposed to make max torque at 3400rpm instead of the claimed 2500rpm. Also, strange how the 2018 graph only starts from 2300rpm. But anyway, I'm not an expert.

 

wouldn't focus on anything below 2500 as they probably weren't at WOT

 

IIRC he picked up around 4mph trap speed so it's making more power. The extra WGDC provided by the BCM should get boost up down low to get the car in to the low 12s where it belongs!

 

sell first - patch later - after customers have done the homework for you. The ultimate way to beta test

seems far too common of practice these days in the software field

 

Extracting extra performance from vehicles is inherently an evolving process as vehicle manufactures make various changes to hardware and software often. Not to mention everyone has different mods, climates, fuels, and operating conditions. The JB4 is a flexible programmable tuning tool. So helping you guys improve performance in new situations is what it was designed for.

 

So 2019s is compulsory to purchase BCM?

 

Fixed it for you And history repeats itself of sorts...cps offsetting, N55 EWG, B58

 

To be fair, they do say in very bold letters, tinker at your own cost. Atleast BMS does. And to me that is fine. Way better than having burnout mode on a 4WD or bending rods on customer cars.

 

Oh, I agree that it is tinker at your own risk. My comment was in reference to history on other platforms where this same type of scenario has played out involving BMS...more than once. I was perfectly fine to not bring it up and let them try to address and explain the issues that the OP is seeing.

There first excuse was to blame the fuel, then there wasn't really much said about the issue aside from vague comments about the JB4 is merely a tool. Then they said this: " post the JB4 log of the specific run in question and lets see where your missing horsepower is!" But a few posts later it's this: "Trap speed should be 3-4mph higher here?" So first it was bad gas, and then they wanted more logs to look for the power that just wasn't getting put down, then it seemed that it was being downplayed and there was no more power. After that they provided basically zero feedback except to mention that they came out with an add-on boost control module. The OP mentioned a firmware update is in development for the 2019s. That was great, but that doesn't really answer the questions of others following the thread as to what the firmware is "fixing" or what was really causing the issue. Is it gain control? Soooo, there are no boost spikes, but a boost control module is needed "which gives us a lot more control over boost targeting." On the 2019s the boost apparently isn't building as smoothly or as early as it did in the 2017-18s. I'm willing to bet the less granular control on the 2019s (without the BCM) swings both ways, and boost exceeding target also happens.

I noted a very obvious issue with throttle closure (I mean, anyone can see that 80% closure that lasts for about two seconds in one of the logs) and noted some boost spikes (or boost that exceeded target). When boost jumps 5 psi in less than 2 secs and 600 rpm, that's a spike, and it causes throttle closure, because that is exactly what the ECU is designed to do when it sees a boost spike. In fact, the ECU is fairly sensitive to even small amounts of boost exceeding expected targets, and it's first response is to close the throttle. Some throttle closure is normal, especially in lower gears. It is often added deliberately via factory programming to a small degree to aid in turbo spooling and maintaining VE. But that was just dismissed summarily with some passive-aggressive commentary. Maybe it is an issue in the factory pid or pwm program; it's near impossible to tell with the limited info at hand, but I can see an obvious issue from what has been posted in this thread. I looked at the logs and made an observation. I never said it was the fault of the JB4 nor did I say anything negative or disparaging toward BMS, I only noted what I saw. My only interest was to help the OP and anyone else looking. It wouldn't be the first time that info shared in a forum by others with knowledge has helped a vendor find solutions...and what did I get for trying to point out a potential issue: a snide comment trying to downplay my knowledge or experience (of which they know nothing and is very extensive, especially on turbocharged engines). Sorry, but I didn't really appreciate that.

 

Nope.. Only for situations where gaining 4-5mph in the 1/4 mile trap speed is less than you are looking for performance wise. We're also not yet sure the BCM is going to be any benefit on a large scale. We've seen some improvements in cars we're working with so if you want more boost, and your logs indicate the car can take more boost, this is another step to get there.

 

We've tuned tens of thousands of vehicles over the years across a wide range of platforms. Tuning and firmware approaches always evolve as the platform and it's customers needs evolve. We'll be here to release JB4 firmware, adjustments, and add on connections as necessary to ensure we remain ahead of the pack. If trying to address customer feedback with free firmware updates and inexpensive add on connections is a drawback then so be it. We figure it's better than releasing a product that can never be updated or adjusted as needs change.

In terms of why you're having a hard time evaluating the throttle movement using the data in front of you I can't say. The data is there and clear as I explained. There are certainly situations where throttle movement and boost control could be hurting performance and if you're experiencing that with your JB4 just post up the specific log so we can help you sort it out.

 

Again, the passive-aggressive snark just comes seething through. I guess it makes you feel superior in some way. Good for you. You obviously took some sort of offense to having things pointed out in logs. Not sure why, as I didn't attack BMS or the tune. The OP was trying to understand why his 1/4 mile times weren't really better than stock. I can read the damn logs just fine, but apparently you can't. I guess it's still bad fuel, or just normal. Yep. Ok.
As I said, I didn't say anything negative toward BMS or the JB4 in this thread until you decided to talk down to someone you know absolutely nothing about and who just might have a hell of a lot of experience tuning, building, racing and winning. Not here to talk about me though, I was just here to try and help the OP. I merely pointed out something that you still want to just pretend isn't there. I can promise you that any desire I might have had to purchase any BMS products has completely vanished due to your attitude, and quite frankly I hope others see you for what you are and your responses cost you a few more sales on this platform.

MarcusDubya77, I hope that BMS is able to get you straight, you get the performance outcomes you were expecting, and you get to have as much fun with the JB4 as Munis, and the others who have it.

 

I'm a little confused why you're in here in a JB4 support thread attempting to provide unsolicited tuning analysis in the first place if you don't even run a JB4 on your C43?

Not really following you on the logs. You provided a poor analysis and I corrected it with reference to a specific log. Hopefully you now understand that when looking at throttle behavior you need to monitor boost in front of the throttle and behind the throttle in the manifold to determine what effect that throttle movement is having before throwing out blanket statements.

That said we'll continue working with OP and any other customer to ensure they are all getting as much safe performance out of their vehicles as they can! His throttle isn't slowing him down (in the logs I've seen) and trap speeds look good. So I think the holdup is likely boost down low during the launch.

 

Can you post actual results of a 2019 with more power/better times that mimic that of the pre-facelift?

 

To me, this is THE key objective. I hope they can sort it out soon. My 2019 comes in a month's time and I really don't know which brand/box actually works on it. I wish I could contribute, but my car isn't here yet.

 

I have lot of respect about your tuning knowledge reading from all your posts previously and I do not think anyone here doubts that even a little bit. I do think though that BMS needs a bit more time to sort this out. Only way we will know is if someone with the 2019 C43 gets the BCM module, let BMS develop a new firmware accordingly and test it. The JB4 originally for our cars were developed on the 2017 and 2018 model, and Terry probably calibrated it accordingly. Which to me kinda explains all the issues with c400, 450 and 2019 models. Unless they have a test 2019 C43 to tinker with, I do not think this is going to get fixed that easily anytime soon.

Marcus shared his dragy results in the JB4 group and it looks like he is loosing majority of his time at launch. The car is bogging down, which is very similar to the problem C450 has. C400 and C450 and by the looks of it, the 2019 C43 does not launch the same way 2017 and 2018 does. I am ofcourse talking about all this from a high level perspective. I have no idea in pure technical terms what is going on.

 

+1

 

What’s the JB4 group? Is it a chat group or forum only accessible by JB4 owners/users. It’s not the N54tech forum, right? Perhaps I should pick up a JB4 ahead of time and follow the goings on over there while I wait for my car to come.

 

Haha nothing like that. Just a whatsapp group for JB4 owners. Once you have bought yours PM me, I will give you the link to join.