[Electron Translator]

Here’s one from today. On E30 and Map 4 (designed for E30).

 

[turnFlatsix]

I have some experience tuning my MK7 GTI and have run the JB4 but I am no expert.

Regarding AFR, the ECU tables can be quite sophisticated. Typical to stay lean (AFR=14.7) until hitting max load for several seconds, especially in the midrange. You can see AFR richen up to around 12.5 later in the log (second gear?). This is typical behavior to cool cylinder temperatures.

In general, Porsche’s engine tuning is exceptionally great. You’re running factory tuning with JB4 just spoofing the ECU into producing more boost.

Would like to see your timing, particularly cylinder correction (knocking). I would trust BMS support so wouldn’t be concerned if they’re happy with your log. I’ve exchanged many emails with Terry and George. The JB4 maps are relatively conservative compared to an ECU map like APR.

BTW: Best way to log is a long straight run at WOT in 3rd and 4th gear. Your engine should redline at 7500rpm. Repeated pulls are best to heat soak but can be tough to find a road long enough while avoiding ending up in jail.

Can you upload the CSV here?

datazap.me | Fast, Free, Interactive Datalogs

datazap.me

 

[ajcarson11]

Hey all -- This post has made me interested in the JB4 again for the following reasons:

• I've always tuned my cars (for better or worse.. its a disease) and therefore I am interested in the extra performance (for fun, and just curiosity, since this is my first turbo car)
• I'm still under CPO warranty for another 13 months and would rather at least feel like i have a shot at retaining my warranty in the event of a big engine failure (this is ironically my first car with a legit warranty)
• I like to tinker and like the fact that the JB4 can be self installed/uninstalled (unlike APR tune which requires shop time to install/uninstall tune)
• The newer revisions of the JB4 firmware appear to close the acceleration performance gap in comparison to APR tune (although I realize APR will have many more safety/driveability upsides)
• For the sake of eventual resale (I know i'm not keeping this car forever) i'd like it to remain 'untuned' -- I only have one mod (200cel downpipe) that is removable to be able to easily return to stock at home to give the next buyer peace-of-mind. I know personally that I wouldn't jump at the opportunity to buy a tuned or previously-tuned car (regardless of the tune quality) -- so I expect similar of others.
• I'm not tracking the car at moment and don't live in a place with fun/canyon roads -- so performance benefits will only be recognized in short durations.
• Price isn't bad ($778 new) in comparison to other do-it-yourself tune (Softronic at $1305)

I do realize that the APR/softronic tune is the better way to go, but given my points above I think the JB4 is worth the test.

With that being said, I don't like the lack of anecdotal feedback on the JB4's use on the 718 platform -- i've scoured the internet and there's just not enough data on how well it works for our cars (outside of this post and a few others in other forums). This makes me hesitant to pay $778 only to find that it doesn't feel great on 93 octane (which is what I plan to stick to) -- Burger doesn't offer a money-back guarantee and requires a 20% restocking fee for returns. I've reached out to them to see if they would be willing to reduce/waive this restocking fee to give me a push to purchase -- In return I'll leave honest feedback (i.e. feedback that isn't trying to justify my purchase) here for others in the community to see.

We will see what they say!

 

[ajcarson11]

And... they have responded just a minute ago.

"We typically can't / don't wait our restocking fee, as it helps offset our costs in the event of returns. You ahve 30 days from the original purchase date to return the JB4 - we typically suggest installing the JB4 and logging map 0 or 1 to make sure everything is working properly."

Hmm... Not sure if its really worth taking a 20% ($155) hit just to test this out... Kind of disappointed that they don't seem to have confidence enough to offer an option.

 

[Electron Translator]

And... they have responded just a minute ago.

"We typically can't / don't wait our restocking fee, as it helps offset our costs in the event of returns. You ahve 30 days from the original purchase date to return the JB4 - we typically suggest installing the JB4 and logging map 0 or 1 to make sure everything is working properly."

Hmm... Not sure if its really worth taking a 20% ($155) hit just to test this out... Kind of disappointed that they don't seem to have confidence enough to offer an option.

I wonder if it’s because it’s a physical product that will be worth less if returned? I had similar concerns but got mine used from a member here.

 

[ajcarson11]

I wonder if it’s because it’s a physical product that will be worth less if returned? I had similar concerns but got mine used from a member here.

I get their response but if they had confidence (or wanted to get the word out in this forum) id imagine they would consider it - they are making profit assuming it doesn't get returned - so the real question is whether it is worth the risk to them that I'll want to return. Seems like a risk worth taking on their part in my mind.

 

[Electron Translator]

Here’s the latest from Terry @ BMS:

“Hi Andy,

Seems normal to me. They run close to stoich and then richen up to low 12s as modeled EGT increases during longer runs. Fuel trims are not maxed out here as well.”

 

[turnFlatsix]

Agree log looks good. You're seeing 14* of advance. That's likely ECU max advance for that IAT. On an ECU flash w/E30 timing could be pushed further.

Is your car a manual? You're leaving acceleration on the table by short shifting at 6400rpm. If you're a PDK just let the car shift itself.

 

[turnFlatsix]

Hmm... Not sure if its really worth taking a 20% ($155) hit just to test this out... Kind of disappointed that they don't seem to have confidence enough to offer an option.

An ECU flash tune is capable of pushing your car further than a piggyback. It's a question of your priorities and your risk tolerance. Any amount of tuning comes with risk.

People typically choose JB4 to reduce risk of having warranty coverage denied because it's less detectable or provides greater plausible deniability to the dealer when submitting a warranty claim versus a flashed ECU. But I bet even a JB4 can be detected if a smart technician goes digging. Those seeking to maximize performance and subjective characteristics will flash the ECU and are willing to risk warranty or flash after coverage expires.

The below table compares tuning options for turbo cars. The take away is there is diminishing returns when pushing the tune further while risk increases exponentially.

Tune	Relative Performance*	Relative Risk**
Stock	60%	100%
Piggyback (JB4)	85%	150%
Piggyback custom (JB4 map 6)	90%	160%
ECU flash (e.g. APR, Cobb)	95%	165%
ECU flash custom (e.g. EQT)	100%	200%

*Relative performance is what’s perceived out of the tune vs stock as opposed to objective measurement of acceleration like quarter-mile MPH or 100-200kph time. Actual objective gain is substantially less. Some of what’s perceived is placebo—you think it’s faster than it really is. For turbo cars, the increase in low end torque can be substantial and is most noticeable during typical road driving from the butt dyno.
**Entirely made up (no data). Assumes risk increases with performance. However, a poorly calibrated tune that performs worse could carry more risk than a good tune that delivers more performance.

 

[Ed @ EQT]

My main issue with the JB4 on this kind car is that by spoofing the MAP sensor signal (to raise actual boost), it’s also throwing off all the temperature models that are in charge of enrichment and other safety protocols. Its also throwing off the airflow and torque modeling, skewing the ignition curve, etc.

The majority of these ECU’s are based on complex models and the MAP signal is one of the main inputs for those models. You can’t heavily skew such a significant input and expect the models to work as designed.

— Ed

 

[Electron Translator]

My main issue with the JB4 on this kind car is that by spoofing the MAP sensor signal (to raise actual boost), it’s also throwing off all the temperature models that are in charge of enrichment and other safety protocols. Its also throwing off the airflow and torque modeling, skewing the ignition curve, etc.

The majority of these ECU’s are based on complex models and the MAP signal is one of the main inputs for those models. You can’t heavily skew such a significant input and expect the models to work as designed.

— Ed

Therefore…?

 

[Ed @ EQT]

Therefore…?

Therefore you run the risk of excess knock and overheating components like cats, turbos, exhaust valves, pistons, etc.

These ECU’s basically run stoich AFR until the modeled temperature values exceed preset thresholds. Then the ECU runs enrichment to keep temps in check. If you throw off these models, the ECU doesn’t know when to go into enrichment.

— Ed

 

[turnFlatsix]

These protections are still in place with a piggyback tuner but you’re operating the engine outside its expected loads which means theoretically you might exceed protection margins. Ed’s example of modeled exhaust gas temperatures is a good one. They will be higher than the ECU expects, but there are other decay tables like IAT that will backoff timing to protect the engine under the increased boost. Knock sensors are there as a last resort. I can’t recommend tracking a car running a piggyback.

That’s where logging is critical. With any tune, you’ll want to stress test the engine, taking it to redline over repeated pulls to check for knock. If you don’t observe cylinder knock events you’re probably OK. Modern engine ECU are highly adaptable to accommodate different fueling, environment conditions, aging,ect.

A good ECU tuner will adjust these tables to optimize protection margins for the increased performance, for example AFR will enrichen sooner under WOT to lambda 0.80-0.85 to control exhaust gas temperature. This is partly why you can extract more from an ECU tune but it’s mostly because a lot more tuning parameters are exposed. Unless price or warranty is a factor an ECU tune is always preferred.

 

[Electron Translator]

Thanks. I don’t plan on tracking the car.

Here’s BMS’ page that describes the differences between it and a flash tune. It mentions the safety provisions you do, and more. I’m not posting this to suggest anyone here is wrong or unskilled. Just adding to the conversation.

JB4 Frequently Asked Questions

The differences between a JB4 vs flash tune and JB4 vs racechip explained in depth.

burgertuning.com

 

[vosadrian]

@Electron Translator, It is great that your tune is working well for you. I and others here just think it is important that others who may read this thread realise the limitations of the tune you are using and make an informed decision when choosing the tuning option they want. For instance, someone planning to do a lot of track laps (a large proportion of Porsche market) would be ill advised to choose an interceptor like the JB4. If you like to tinker and don't plan track work, it sounds like a good option for you. Just realise that you will make less performance than a set and forget APR tune, but you have some benefits in terms of tune removal and detection.

For me, I actually like the Cobb eco system except that they have poor OTS maps included, so you are almost obligated to pay for additional maps or pro tune. If you do, you can have whatever you want with the right pro tuner. If you just want set and forget, it is hard to beat APR for quality of mapping and price.

 

[Electron Translator]

@Electron Translator, It is great that your tune is working well for you. I and others here just think it is important that others who may read this thread realise the limitations of the tune you are using and make an informed decision when choosing the tuning option they want. For instance, someone planning to do a lot of track laps (a large proportion of Porsche market) would be ill advised to choose an interceptor like the JB4. If you like to tinker and don't plan track work, it sounds like a good option for you. Just realise that you will make less performance than a set and forget APR tune, but you have some benefits in terms of tune removal and detection.

For me, I actually like the Cobb eco system except that they have poor OTS maps included, so you are almost obligated to pay for additional maps or pro tune. If you do, you can have whatever you want with the right pro tuner. If you just want set and forget, it is hard to beat APR for quality of mapping and price.

Do you feel like that hasn’t been clear in the thread so far? I just find it interesting the folks who are keen to keep bringing up how this isn’t as good as something else. I’m happy and enjoying it. Others can enjoy what they want. I’m just sharing my experience.

 

[Electron Translator]

From BMS on the differences between JB4 and a tune:

The JB4 is a programmable computer that attaches between the ECU and vehicle sensors allowing it to adjust your vehicle’s tuning by tapping into areas of the factory flash mapping that are not normally available. Unlike other similar-looking tuning systems the JB4 is also able to tap in to CANbus - analogous to a spinal cord - allowing it to communicate and receive information from not only the ECU but also the transmission computer, stability control module, dash module, and many others. This CANbus connection provides a complete set of real-time operational data which is then dynamically incorporated into your JB4 tuning.
A flash tune, on the other hand, modifies the tables on the ECU directly for higher performance. Usually loaded via the vehicles gateway on the OBDII port, but in some applications directly to the ECU by drilling a hole or disassembling the ECU to access the processor inside.

Safety: While the flash tune can adjust more tables directly there is also a lot more that can go wrong. Many flash tunes adjust the knock sensor feedback and other critical tables, sometimes unwittingly, creating a much higher risk of engine damage. The quality of the flash tune depends entirely on the skill of the person who wrote it and in many cases flash maps are purchased from a single murky source and resold by several tuners without high levels of R&D performed. Flash tuning is also limited to the factory logic paths which, while generally sufficient for factory vehicles, can become inadequate when dealing with higher-powered and modified vehicles. The JB4, on the other hand, cannot interfere with the factory safety systems by design. It can only run your tuning from the extensively tested factory programmed tuning tables while also adding a robust range of additional safety systems not possible flash-only. Including going into bypass mode if boost exceeds a user defined value, AFR in either bank goes lean, fuel trims in either bank max out or vary dramatically from each other, fuel pressure drops below a specific value, etc. The JB4 continually monitors your tuning in real time via CANbus and turns off if things go sideways. It’s a lot like having a professional tuner sitting in your passenger seat watching over your engine data in real time every time you floor it.

Performance: The JB4 is able to achieve a dramatic performance increase, completely transforming your vehicle. But it’s also more limited relative to a flash tune as it is working off the factory flash tables. While performance is usually very similar between the two there are a few things the JB4 just can’t do including changing fuel injection timing (exhaust pops and bangs), raising the RPM limiter, adjusting valve timing, and in some cases, raising the speed limiter.