Pure Drivetrain Solutions

harkes · 08-31-2022, 02:12 AM

Quote:

Originally Posted by lucasborka

The option line pressure bump only bumps the pressure when needed. Which is rarely needed on the N55

OK. So dynamic then, thanks

thejeremyman9 · 08-31-2022, 08:42 PM

Quote:

Originally Posted by lucasborka

The option line pressure bump only bumps the pressure when needed. Which is rarely needed on the N55

Curious where you got this info from?

lucasborka · 08-31-2022, 10:53 PM

Quote:

Originally Posted by thejeremyman9

Curious where you got this info from?

You can read it in xhp online wiki, the line pressure option allows for 5-15% more PEAK pressure. Not constant, so only activated when the box senses slip

LA1Z24 · 09-01-2022, 05:10 AM

Quote:

Originally Posted by lucasborka

You can read it in xhp online wiki, the line pressure option allows for 5-15% more PEAK pressure. Not constant, so only activated when the box senses slip.

That isn't true. It is load based. Over a certain torque number and the bump gets added. When the box slips, it immediately cuts boost down to 8psi.

This is how I found out I needed a new transmission.

D1rty_b1rd · 09-04-2022, 06:54 AM

Quote:

Originally Posted by LA1Z24

Quote:

Originally Posted by lucasborka

You can read it in xhp online wiki, the line pressure option allows for 5-15% more PEAK pressure. Not constant, so only activated when the box senses slip.

That isn't true. It is load based. Over a certain torque number and the bump gets added. When the box slips, it immediately cuts boost down to 8psi.

This is how I found out I needed a new transmission.

What exactly were the symptoms when you found this out? Im having an issue where i loose complete power around 120mph in 4th or 5th gear if i remember correctly. 5th most likely. Havent been home in months to replicate. Issue started becoming noticeable during one of the shift sector events.

LA1Z24 · 09-04-2022, 07:07 PM

50 RPM clutch slip causes the TCU to tell the DME to dump boost. Happens in 6th, the weakest gear.

paimon.soror · 09-05-2022, 10:36 PM

Interesting, I've been driving on stage 3 for at least 20k miles. Now with some of this conversation, i might drop down to stage 1 just for the sake of continued longevity as I'm now at about 55k (already did a fcpeuro oil change kit about 10k ago which came with liquimoly...seems fine)

lens · 09-06-2022, 05:35 AM

Quote:

Originally Posted by paimon.soror

Interesting, I've been driving on stage 3 for at least 20k miles. Now with some of this conversation, i might drop down to stage 1 just for the sake of continued longevity as I'm now at about 55k (already did a fcpeuro oil change kit about 10k ago which came with liquimoly...seems fine)

I've been on stage 3 for the past 60k miles, with heavy track time, and haven't had an issue yet.

09-04-2022, 07:07 PM	#28
LA1Z24 Captain 433 Rep 882 Posts Drives: 2014 435i M Sport Join Date: Oct 2020 Location: Long Island iTrader: (0)	50 RPM clutch slip causes the TCU to tell the DME to dump boost. Happens in 6th, the weakest gear.
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09-05-2022, 10:36 PM	#29
paimon.soror Captain 638 Rep 983 Posts Drives: 2016 F36 435x MSport Join Date: Oct 2017 Location: Hartford, CT iTrader: (3) Garage List 2016 BMW 435xi GC [6.00]	Interesting, I've been driving on stage 3 for at least 20k miles. Now with some of this conversation, i might drop down to stage 1 just for the sake of continued longevity as I'm now at about 55k (already did a fcpeuro oil change kit about 10k ago which came with liquimoly...seems fine)
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