JB4 1/4 mile time update
The following 4 users liked this post by munis:
AMG C43 3LV6 (11-12-2018),
C43Ayemgee (11-12-2018),
GuardianVA (11-13-2018),
waisoserious (11-12-2018)
#2
Newbie
Join Date: Dec 2016
Posts: 14
Likes: 0
Received 10 Likes
on
3 Posts
2017 C43 AMG, 2011 Porsche Cayenne Turbo, 2015 GMC Sierra Denali
Do you have the green fuel plug installed?? I tried it after the latest update but my car idled like old school NA muscle then died. So mines unplugged
11.4 is movin.. congrats
11.4 is movin.. congrats
#3
Do you have a 0-60 time?
The following users liked this post:
AMG C43 3LV6 (11-13-2018)
#5
Member
What did you mean by acting weird? The sample range is a bit compressed in the log, but overall, log looks good from what I can see. Kinda surprised to see the IAT at that high for 5C, but overall, doesn't look like anything is out of sorts. If you wanna post up the .csv file for the log, I'd be glad to look at it scaled out.
That time and trap are very impressive. Congrats!
That time and trap are very impressive. Congrats!
#6
MBWorld Fanatic!
Thread Starter
Join Date: Nov 2016
Location: Toronto, ON
Posts: 1,527
Received 284 Likes
on
194 Posts
2021 Mercedes C63s AMG Coupe
Yes, Best is around 3.35, average is 3.4.
What did you mean by acting weird? The sample range is a bit compressed in the log, but overall, log looks good from what I can see. Kinda surprised to see the IAT at that high for 5C, but overall, doesn't look like anything is out of sorts. If you wanna post up the .csv file for the log, I'd be glad to look at it scaled out.
That time and trap are very impressive. Congrats!
That time and trap are very impressive. Congrats!
Last edited by munis; 11-13-2018 at 11:30 AM.
The following users liked this post:
AMG C43 3LV6 (11-13-2018)
#7
Member
Ahh, OK, I follow.
Yes, the colder the intake air to the turbo, the more power you will get. The colder the air, the denser it is. This increased density of air leads to more fuel-air mixture and overall increased power. The car will be more power efficient the colder the ambient air. It will be less fuel efficient though, as the volume of fuel injected goes up to match the increased air density. Given the level of boost you are running, once you are getting below 0 C, you might be seeing less power because you are leaning out past the point where the car can keep up with the air-fuel target and it reduces power to compensate. In theory, you if you had sufficient fuel injection capacity, you could steadily make more power until the oxygen started to condense out (-183 C). Turbo cars just like cold air, and in Canada you have plenty of that in the winter, lol.
Yes, the colder the intake air to the turbo, the more power you will get. The colder the air, the denser it is. This increased density of air leads to more fuel-air mixture and overall increased power. The car will be more power efficient the colder the ambient air. It will be less fuel efficient though, as the volume of fuel injected goes up to match the increased air density. Given the level of boost you are running, once you are getting below 0 C, you might be seeing less power because you are leaning out past the point where the car can keep up with the air-fuel target and it reduces power to compensate. In theory, you if you had sufficient fuel injection capacity, you could steadily make more power until the oxygen started to condense out (-183 C). Turbo cars just like cold air, and in Canada you have plenty of that in the winter, lol.
The following users liked this post:
munis (01-07-2019)
Trending Topics
#9
If Im interpreting the log correctly it looks like fuel trims are being maxed out which is causing your motor to run lean. Based on where there are tiny surges of AFR and it correlates to where trims are pinned at max of 44.
What fuel are you running? I assume you havent installed the green plug for extra fueling. A leaned out boosted motor can be very risky..
Pretty impressive trap speed
What fuel are you running? I assume you havent installed the green plug for extra fueling. A leaned out boosted motor can be very risky..
Pretty impressive trap speed
#10
#12
Member
If Im interpreting the log correctly it looks like fuel trims are being maxed out which is causing your motor to run lean. Based on where there are tiny surges of AFR and it correlates to where trims are pinned at max of 44.
What fuel are you running? I assume you havent installed the green plug for extra fueling. A leaned out boosted motor can be very risky..
Pretty impressive trap speed
What fuel are you running? I assume you havent installed the green plug for extra fueling. A leaned out boosted motor can be very risky..
Pretty impressive trap speed
Again, very impressive Munis.
#13
Still struggling to match your 0 to 60, though I am getting a bit better at launching (still waiting on your launching video ) and managed to post a 3.66 before it started raining.
It's getting too cold and wet now so will have to wait until the spring to try and better it and hopefully find a stretch of road to do the 1/4 without endangering anyone.
For now I will blame the extra heft of my coupe for the .3 second deficit
It's getting too cold and wet now so will have to wait until the spring to try and better it and hopefully find a stretch of road to do the 1/4 without endangering anyone.
For now I will blame the extra heft of my coupe for the .3 second deficit
Last edited by ShakyTom; 11-13-2018 at 10:59 PM.
#15
Senior Member
If Im interpreting the log correctly it looks like fuel trims are being maxed out which is causing your motor to run lean. Based on where there are tiny surges of AFR and it correlates to where trims are pinned at max of 44.
What fuel are you running? I assume you havent installed the green plug for extra fueling. A leaned out boosted motor can be very risky..
Pretty impressive trap speed
What fuel are you running? I assume you havent installed the green plug for extra fueling. A leaned out boosted motor can be very risky..
Pretty impressive trap speed
#16
MBWorld Fanatic!
Thread Starter
Join Date: Nov 2016
Location: Toronto, ON
Posts: 1,527
Received 284 Likes
on
194 Posts
2021 Mercedes C63s AMG Coupe
Ahh, OK, I follow.
Yes, the colder the intake air to the turbo, the more power you will get. The colder the air, the denser it is. This increased density of air leads to more fuel-air mixture and overall increased power. The car will be more power efficient the colder the ambient air. It will be less fuel efficient though, as the volume of fuel injected goes up to match the increased air density. Given the level of boost you are running, once you are getting below 0 C, you might be seeing less power because you are leaning out past the point where the car can keep up with the air-fuel target and it reduces power to compensate. In theory, you if you had sufficient fuel injection capacity, you could steadily make more power until the oxygen started to condense out (-183 C). Turbo cars just like cold air, and in Canada you have plenty of that in the winter, lol.
Yes, the colder the intake air to the turbo, the more power you will get. The colder the air, the denser it is. This increased density of air leads to more fuel-air mixture and overall increased power. The car will be more power efficient the colder the ambient air. It will be less fuel efficient though, as the volume of fuel injected goes up to match the increased air density. Given the level of boost you are running, once you are getting below 0 C, you might be seeing less power because you are leaning out past the point where the car can keep up with the air-fuel target and it reduces power to compensate. In theory, you if you had sufficient fuel injection capacity, you could steadily make more power until the oxygen started to condense out (-183 C). Turbo cars just like cold air, and in Canada you have plenty of that in the winter, lol.
If Im interpreting the log correctly it looks like fuel trims are being maxed out which is causing your motor to run lean. Based on where there are tiny surges of AFR and it correlates to where trims are pinned at max of 44.
What fuel are you running? I assume you havent installed the green plug for extra fueling. A leaned out boosted motor can be very risky..
Pretty impressive trap speed
What fuel are you running? I assume you havent installed the green plug for extra fueling. A leaned out boosted motor can be very risky..
Pretty impressive trap speed
Naah, he's not running lean. Max trim is 50, so he has plenty of overhead. His AFR looks good, the only point over 15 is early on in the log when he is at part throttle, which is normal. Only thing I noticed was what might be a little boost oscillation, but the scaling is compressed, so it is hard to see for sure.
Again, very impressive Munis.
Again, very impressive Munis.
Still struggling to match your 0 to 60, though I am getting a bit better at launching (still waiting on your launching video ) and managed to post a 3.66 before it started raining.
It's getting too cold and wet now so will have to wait until the spring to try and better it and hopefully find a stretch of road to do the 1/4 without endangering anyone.
For now I will blame the extra heft of my coupe for the .3 second deficit
It's getting too cold and wet now so will have to wait until the spring to try and better it and hopefully find a stretch of road to do the 1/4 without endangering anyone.
For now I will blame the extra heft of my coupe for the .3 second deficit
Did he give an ETA?
#17
Member
Thank you so much for explaining it! Makes perfect sense. My offer to join the JB4 whatsapp group is still there, haha.
May be @Guardian VA can explain this better, but a member here named 18Bora found out the C43 with JB dynos really low which does not match ET and trap speed seen on the track. A reason (my best guess) for that is that the airflow numbers on the dyno (often dependent on the cooling fan ahead) does not correlate with the airflow vs boost table in the ECU. So the ECU pulls back timing significantly on the noddy for cars with JB. The numbers align when the cars are running on the road, so the ECU gives you almost full power.
May be @Guardian VA can explain this better, but a member here named 18Bora found out the C43 with JB dynos really low which does not match ET and trap speed seen on the track. A reason (my best guess) for that is that the airflow numbers on the dyno (often dependent on the cooling fan ahead) does not correlate with the airflow vs boost table in the ECU. So the ECU pulls back timing significantly on the noddy for cars with JB. The numbers align when the cars are running on the road, so the ECU gives you almost full power.
As far as the dyno thing...could be any number of reasons. 18bora may have been on a Mustang Dyno, which usually puts out numbers lower than any other dyno make/model (usually around 10-15% lower than Dynojet, which is what BMS has in-house). Even if it is on a Dynojet, different models may be load based vs inertia based, which means the car on the dyno may not actually be seeing the same engine load as when it is on the street accelerating. Plus, dyno runs for a chart are done in a single gear usually, so you are only getting a "snapshot" of power at a set load range, rather than across multiple gears (and therefore varying load) as in a 1/4 mile run.