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Terry @ BMS's Avatar
Terry @ BMS Terry @ BMS is offline
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Default How wideband fuel control works - 07-29-2020, 08:47 AM

John Bushbaum scam (otherwise known as Tork Tune) is up to his old tricks spreading misinformation about the JB4 tuning. He's either intentionally trying to mislead people or just ignorant. I'm not sure what would be worse lol. Anyway a customer asked me to address John's allegations which took like 20 min to write up so figured I might as well just post it here for posterity.

Quote:
Originally Posted by John Bushbaum@Tork
Do you understand what the ECU is trying to fight off when you run a piggy back? Do you understand what fuel correction, ignition correction, target lambda correction, and airflow/boost correction does to your engine? These are all things that are happening when you run a piggy back on damn near any ECU from 2008 to current.
John you still seem to completely misunderstand how full time closed loop fuel systems work on modern fuel injected vehicles. Frankly it’s is a little scary given the experience you claim to have? I’ll try to clean it up for enthusiasts who might be curious how it all actually works. Read slowly and maybe you’ll learn something too!

Each engine bank is equipped with a wideband lambda sensor that is continually feeding air/fuel mixture data to the ECU in real time. This data is then combined with fuel pressure, engine speed, load (let’s simplify it to boost for our purposes), and a few additional parameters and learned trims, to determine injector pulse width (IPW) or how wide the fuel injector needs to be opened to maintain the air/fuel target. This determines how much fuel volume is injected in to the engine. As boost is increased the wideband sensor detects this in real time and loops back to the ECU to increase IPW in real time.

The ECU maintains fuel trims which represent how much fuel was actually vs how much fuel the ECU programming expected to inject for the conditions. The differences are broken into long and short term fuel trims with long term trims actually being added back in to the future calculations.

Now introduce a piggyback to the fuel system. Let’s take a basic system that does not have fuel control like say RaceChip. We’ll also ignore boost and ignition for the moment for simplicity although their operation is fairly analogous.

Just like before as boost is increased more oxygen is introduced in to the exhaust and in real time the lambda sensor detects that oxygen and relays that back to the ECU to increase IPW to maintain the lambda target. The difference is, even more boost is added than before, more oxygen is detected, so IPW opens even more to inject more fuel and hit the air/fuel target. This happens instantaneously as the sensor is sampled effectively continuously (100s of times per second).

What you fail to understand is more fuel is instantly injected despite the fact that the boost (load) levels in the ECU are effectively the same despite actual boost being higher. This is because the higher boost levels provide more oxygen which the sensor reports back instantly. It’s not only the nature of real time closed loop systems, it’s the entire point. We no longer live in a speed density world. But now a potential problem comes up. The ECU expected to inject fuel for say 14psi but actually injected fuel for 18psi. How does it reconcile this? The answer is simple, the variance is reflected in higher fuel trims which are then fed back in to the PID forever after rendering your entire adaption concern moot.

Now with more advanced systems like the JB4 we actually attach to the oxygen sensors and are able to adjust the target air/fuel ratio to optimize performance. As it turns out with the Stinger the factory air/fuel ratio is too rich for optimal performance so we run a leaner target, which has the effect of lowering the fuel trims offsetting the increase caused by the higher boost levels being run.

Big picture, none of this manipulation has a “negative” effect on engine operation. In fact to the contrary it’s just the ECU and lambda sensor doing what they always do whether you’re running a tuning system or not. Your assertion that the ECU is “fighting” to return to some neutral fuel range is simply false. That analogy only partially holds up with ignition timing corrections which we can get to in another discussion.

Now there is also a caveat which will lead to your next assertion below. The fuel system does have a high and low plausibility range we need to operate between. When you get more than around 40% above or 40% below it’s estimated fuel trims it caps IPW and/or throws a fault code. Of course with the JB4 since we’re increasing fuel trims with boost and lowering them with a leaner air/fuel target, they effectively cancel out providing a lot of range here. So much that we can hit 460whp+ on stock turbos with E85 no problem. But say 500whp now we need to extend that range by either adding extra fuel around the system (WMI) or adjusting the range directly in the ECU. Worth noting the high pressure fuel pump separately runs out of steam around 460whp so the meth becomes a double benefit.

Quote:
Originally Posted by John Bushbaum@Tork
There is a reason you have to run a "back end flash" on a BMW, Audi, VW, Porsche, (insert any fast car running a piggy back and you will see its running a "back end flash" to fix these issues).
We have JB4 tuned BMW M5s running 10.1 seconds in the mile on the factory flash, and mid-low 10s for the 911.1 and 911.2 Porsche models. We’ve even got JB4 only Acura NSXs running mid 10s. But to better understand why we need to flash at some performance point see the last paragraph above. It’s a simple fact that certain things can only be done via flash tuning. Such as adjusting those plausibility ranges on IPW (e.g. adjusting fuel scalars), changing valve/VANOS timing, or making dramatic ignition advance changes from the factory profiles. That’s why for all applications with open flash tuning we develop and publish free back end flash maps for people looking to push records. Which of course is the minority of our customer base but BMS was founded with racing roots and we’ve never forgotten them.


Burger Motorsports
Home of the JB4 the worlds most popular turbocharged tuning system!

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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Lil Ripper Lil Ripper is offline
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Default John who? - 07-29-2020, 09:51 AM

Thanks for sharing, I learned something today!
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Djfourmonie Djfourmonie is offline
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Default 08-06-2020, 06:37 AM

During a random conversion via email -

"I wouldn't let Tork tune my lawnmower."
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Terry @ BMS's Avatar
Terry @ BMS Terry @ BMS is offline
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Default 08-16-2020, 12:18 PM

Quote:
Originally Posted by Djfourmonie
During a random conversion via email -

"I wouldn't let Tork tune my lawnmower."


Burger Motorsports
Home of the JB4 the worlds most popular turbocharged tuning system!

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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djerickd djerickd is offline
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Default 08-20-2020, 04:07 PM

thanks for the info
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deerok78 deerok78 is offline
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Default 08-22-2020, 07:04 PM

Quote:
Originally Posted by Djfourmonie
During a random conversion via email -

"I wouldn't let Tork tune my lawnmower."
I got into it with him too, in the N group... I got Dyno'd and posted the results ....as soon As I mentioned JB4 he stuck his stupid nose in to discredit my dyno numbers and JB4 as not being a "REAL" tune....

My post got deleted cause of him, cause I went in..... I've had JB4 for almost a year now and its been great and I saw almost 40hp gains in map 2 with bolt ons

why would anybody buy anything from such a unprofessional dude is beyond me.

He has such a hard on to try to slander JB4, like he's jealous about it lol ...I left that group.
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Djfourmonie Djfourmonie is offline
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Default 08-22-2020, 07:20 PM

Quote:
Originally Posted by deerok78
I got into it with him too, in the N group... I got Dyno'd and posted the results ....as soon As I mentioned JB4 he stuck his stupid nose in to discredit my dyno numbers and JB4 as not being a "REAL" tune....

My post got deleted cause of him, cause I went in..... I've had JB4 for almost a year now and its been great and I saw almost 40hp gains in map 2 with bolt ons

why would anybody buy anything from such a unprofessional dude is beyond me.

He has such a hard on to try to slander JB4, like he's jealous about it lol ...I left that group.
Aka PTP from Neon/Caliber SRT-4 community. He would argue with major Mopar supporters.

His 500whp Veloster has only ran 12.5@117 on slicks. claims another Veloster made 310hp but only ran mid 13's.

Go to his YouTube channel and look at videos from almost 10 years ago.
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