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jpuehl jpuehl is offline
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Default Tranny short shifting and throttle closures - 10-11-2017, 04:17 PM

This past weekend I upgraded my JB4 from version 10 to 16 and also went with the MHD JB4 BEF and have noticed the car not running as well as it did with just the JB4 on version 10. I made a couple logs, found below. The car seems to be short shifting second gear sometimes and/or the throttle opening seems to be all over the place. I usually use MAP 5 but switched to MAP 1 in an effort to troubleshoot this issue. My car's configuration is below. Tonight I'll probably try MAP 0 and/or switch back to firmware version 10. Anyone have any ideas what could be going on?

Car: '12 135i DCT 29k miles.
Mods: VRSF 7" HD FMIC, BMS intake.
92 Oct fuel only.

All tests were done with the shifter in Sport mode. Row 1 in the log I added comments about how the pull was done.
Attached Files
File Type: csv JB4_Only_Map_5_Testing.csv (5.9 KB, 5 views)
File Type: csv JB4_BEF_Map_5_Testing.csv (10.2 KB, 7 views)
File Type: csv JB4_BEF_Map_1_Testing.csv (6.2 KB, 8 views)
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Steve @ BMS/Fuel-It!'s Avatar
Steve @ BMS/Fuel-It! Steve @ BMS/Fuel-It! is offline
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Default 10-11-2017, 06:47 PM

Best to start with good 3rd gear logs from 2k to redline to let adaptions take place and provide a better log for review. All I really see in the logs is a lot of wheel spin or trans slip.



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jpuehl jpuehl is offline
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Default 10-12-2017, 07:45 AM

Quote:
Originally Posted by Steve @ BMS/Fuel-It!
Best to start with good 3rd gear logs from 2k to redline to let adaptions take place and provide a better log for review. All I really see in the logs is a lot of wheel spin or trans slip.
Thanks Steve. I was going to try to get more logs last night but it started raining after I got off work. Anyway, how can I tell I had wheel spin or tranny clutch slip by looking at the logs? I didn't feel any slip and looking at the log of JB4 MAP 1 + PUMP BEF, the throttle was 100% from beginning to when I let off in 3rd gear; 1st shifted to 2nd at ~6700 rpm then into 3rd at ~5300 with no change in throttle or pedal. I'm just asking to get a better idea of reading the logs myself. I know since the upgrade in firmware and adding the PUMP BEF the car hasn't been running right from a standing start, such as at a light.

I also found out last night that I can't change JB4 setting from 4/2 to 4/0 to use just the JB4; the setting goes back to 4/2 "on it's own". Does that sound right? I was hoping to eliminate the BEF as a variable without having to flash to STOCK.

Thanks for the help, it's appreciated.
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Default 10-12-2017, 04:39 PM

RPM slope should be a nice straight ramp, not jagged or with a hump in the middle of it.

Not sure what your menu issue is, that doesn't sound correct and not an issue I typically hear of.

Might want to try reloading your flash. I'd also raise the boost safety limit when running a flash. With the flash, you need to run on 4/2...do not run 4/0.



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jpuehl jpuehl is offline
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Default 10-13-2017, 08:27 AM

Quote:
Originally Posted by Steve @ BMS/Fuel-It!
RPM slope should be a nice straight ramp, not jagged or with a hump in the middle of it.

Not sure what your menu issue is, that doesn't sound correct and not an issue I typically hear of.

Might want to try reloading your flash. I'd also raise the boost safety limit when running a flash. With the flash, you need to run on 4/2...do not run 4/0.
Thanks Steve. Tonight I'll reload both the MHD Stock flash and the BMS PUMP BEF and see what that does. I'll also rise my boost safety limit; I guess I'll try 18. The reason for wanting to try 4/0 was to remove the BEF from the equation as it felt as if the car ran better before the BEF, and firmware update.

I wish there was a way to add the wheel speed when logging. If the front wheel(s) are rotating at 10 rpm, for example, and the back are at 50 rpm (corrected for tire size difference), then would definitely be some wheel spin. If the engine is accelerating at a faster rate than the back wheels (corrected for gear ratios of the tranny and diff), clutch slippage could be an issue.
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CedarPerformance CedarPerformance is offline
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Default 10-13-2017, 08:42 AM

Quote:
Originally Posted by jpuehl
Thanks Steve. Tonight I'll reload both the MHD Stock flash and the BMS PUMP BEF and see what that does. I'll also rise my boost safety limit; I guess I'll try 18. The reason for wanting to try 4/0 was to remove the BEF from the equation as it felt as if the car ran better before the BEF, and firmware update.

I wish there was a way to add the wheel speed when logging. If the front wheel(s) are rotating at 10 rpm, for example, and the back are at 50 rpm (corrected for tire size difference), then would definitely be some wheel spin. If the engine is accelerating at a faster rate than the back wheels (corrected for gear ratios of the tranny and diff), clutch slippage could be an issue.

The car already tells you if wheel spin is a problem by flashing the traction control light when any sort of traction intervention is occurring. Sometimes it is hard to see the traction light flash when you are hurdling 3500lbs down the road in the middle of the city.

Each wheel should rotate at the same speed as the others, and if any wheel spins faster or slower than the others, traction control takes action.

When traction control takes action, it flashes the light on the dash to warn the driver of slip.

If you are not seeing a light flash, you may not be slipping. You also may not be seeing it flash since you are road-testing the car instead of dyno testing. More focused on the road, that's a good thing.

What you can do to eliminate wheel spin from the equation is hold down the DTC button down until traction is completely disabled. There are 3 settings, On, Sport, and Off. No lights on the dash is on, pressing the button goes to a sport mode where traction intervenes less, but still intervenes, holding it down will disable it completely.

Don't forget, the JB4 is a tuning tool, not a diagnostic tool.
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jpuehl jpuehl is offline
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Default 10-13-2017, 09:18 AM

Quote:
Originally Posted by CedarPerformance
The car already tells you if wheel spin is a problem by flashing the traction control light when any sort of traction intervention is occurring. Sometimes it is hard to see the traction light flash when you are hurdling 3500lbs down the road in the middle of the city.

Each wheel should rotate at the same speed as the others, and if any wheel spins faster or slower than the others, traction control takes action.

When traction control takes action, it flashes the light on the dash to warn the driver of slip.

If you are not seeing a light flash, you may not be slipping. You also may not be seeing it flash since you are road-testing the car instead of dyno testing. More focused on the road, that's a good thing.

What you can do to eliminate wheel spin from the equation is hold down the DTC button down until traction is completely disabled. There are 3 settings, On, Sport, and Off. No lights on the dash is on, pressing the button goes to a sport mode where traction intervenes less, but still intervenes, holding it down will disable it completely.

Don't forget, the JB4 is a tuning tool, not a diagnostic tool.
Thanks for the response!

I'm not trying to use the JB4 to diagnose a problem, just trying to figure out why the car ran great before the JB4 firmware update and the addition of the JB4 PUMP BEF via MHD. The last log I posted had the trans in Sport mode, the Sport mode button pressed/on and the TC/DSC off, and the car ran the same.
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