Off target, under boost....JB4 Tuned Car

M3 Eater · 04-29-2011, 09:39 AM

Let me start by saying, JB4 is not the cause directly ( I think). Jb4 is improving every day and now offers more paramters that can be logged. These include ECU psi and Targets. (awesome)

With this new feature in interface 4/20 and firmware 4/22, I have discovered that the leak I have been searching for was really my DME suddenly targeting much lower in the middle of a pull on boost applications 16psi and higher.

Here is a link to the post on n54. Toward the end are the logs with meth additive set to 3.5 on the (2nd) log and 4.5 on the (1st) log. DME dips a hair in the 3.5 log but a bunch in the 4.5 resulting in less net boost at the higher setting.

Remember... scroll to the bottom to see the logs with the ECU target and readings.

Anyone have an idea why the DME would suddenly dip boost. Doesn't temp play a role there to some extent? I have an ETS street fmic and meth.

http://www.n54tech.com/forums/showth...683#post181683

M3 Eater · 04-29-2011, 01:28 PM

lowered my boost gain setting on jb4 and saw a huge improvemnet, but DME is dipping half way through the gear, JB4 and WPM try hard to compensate to stay on target, looks like a leak, but its the ECU cutting boost.

What are some reasons that the ECU cuts boost?

Temp, overshoot, throttle closure??

HELP PLEASE!

Beemw335 · 04-29-2011, 01:34 PM

Datalog some 3rd gear runs and post them so we could see whats hapening.

04-29-2011, 09:39 AM	#1
M3 Eater Major 36 Rep 1,054 Posts Drives: 335i Sedan Join Date: May 2010 Location: Unknown iTrader: (3) Garage List 2007 335i [0.00]	Off target, under boost....JB4 Tuned Car Let me start by saying, JB4 is not the cause directly ( I think). Jb4 is improving every day and now offers more paramters that can be logged. These include ECU psi and Targets. (awesome) With this new feature in interface 4/20 and firmware 4/22, I have discovered that the leak I have been searching for was really my DME suddenly targeting much lower in the middle of a pull on boost applications 16psi and higher. Here is a link to the post on n54. Toward the end are the logs with meth additive set to 3.5 on the (2nd) log and 4.5 on the (1st) log. DME dips a hair in the 3.5 log but a bunch in the 4.5 resulting in less net boost at the higher setting. Remember... scroll to the bottom to see the logs with the ECU target and readings. Anyone have an idea why the DME would suddenly dip boost. Doesn't temp play a role there to some extent? I have an ETS street fmic and meth. http://www.n54tech.com/forums/showth...683#post181683 __________________ JB4 beta 15 ohms FSB,AEM inline filter/ CM 10, ETS fmic, ER custom made charge pipe,TSW Donnington 18's,Simitumo HTRZ3, Injen DCI, AR DPs, Forge DVs, AA SLD, Koni FSD, ZSP springs.
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04-29-2011, 01:28 PM	#2
M3 Eater Major 36 Rep 1,054 Posts Drives: 335i Sedan Join Date: May 2010 Location: Unknown iTrader: (3) Garage List 2007 335i [0.00]	lowered my boost gain setting on jb4 and saw a huge improvemnet, but DME is dipping half way through the gear, JB4 and WPM try hard to compensate to stay on target, looks like a leak, but its the ECU cutting boost. What are some reasons that the ECU cuts boost? Temp, overshoot, throttle closure?? HELP PLEASE! __________________ JB4 beta 15 ohms FSB,AEM inline filter/ CM 10, ETS fmic, ER custom made charge pipe,TSW Donnington 18's,Simitumo HTRZ3, Injen DCI, AR DPs, Forge DVs, AA SLD, Koni FSD, ZSP springs.
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04-29-2011, 01:34 PM	#3
Beemw335 Colonel 62 Rep 2,013 Posts Drives: 335i Join Date: Mar 2011 Location: My car is my home iTrader: (2)	Datalog some 3rd gear runs and post them so we could see whats hapening.
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