I have been fighting a misbehaving tune for a couple months. Unstable idle, poor low speed drivability and more recently unstable boost curve. I spent 30-40hrs chasing a good tune for idle and drivability and more recently scatching my head at unstable boost curve and seemingly ever changing fuel requirements. I also spent hours trying to make the MS boost control work properly. Recently I installed a new wastegate and new signal line all to no avail. Today I removed the signal line to the MS and replaced it with new one and installed a temporary boost gauge.
Hit the hwy for another pull and saw 13-13.5psi on both the boost gauge and MS. Idle now at 38-40kpa instead of 43-45kpa. Seems the silicone hose deteriorated enough in 6 months to cause a poor signal to MS.
I'll be replacing it permanently with a hard line.
Hopefully this week I can fix the idle, low speed cruise and boost control. Looks like good weather for next weekend.
BTW, yesterday I drove a total of 220 miles to run the car at the dragstrip only to have the dragstrip closed due to flooding. So nice that they updated the website. Assholes!
MS MAP Signal - Lesson Learned the hard way!
Yes, there's a boost table. Looks a lot like the VE or spark advance tables, except (when I worked with it a little over a year ago on an MS2 setup) fewer total cells. It's 8x8 if I remember correctly. Spots between cells are interpolated so that it's smooth.Shadow wrote:Can ms do rpm dependent boost?
Like 7psi then progressively goes to 20psi after 5k?
Jeremy
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marc79euro645
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I recently experienced a weird problem.
under boost in 4th gear the engine burped,& blew a charge hose. I limped home but the car wasn't right. After some searching I discovered my adjustable cam timing gear had slipped & was way retarded. I set it back a few degrees advanced, & this time I locked the position with a short section of 5mm threaded rod,secured by the washer & bolt.
I like the advanced cam,not sure how many degrees , but it really improves bottom end response, & spool.
now if my back would let me straighten up, I'd be back to where I was about a week ago.
marc
under boost in 4th gear the engine burped,& blew a charge hose. I limped home but the car wasn't right. After some searching I discovered my adjustable cam timing gear had slipped & was way retarded. I set it back a few degrees advanced, & this time I locked the position with a short section of 5mm threaded rod,secured by the washer & bolt.
I like the advanced cam,not sure how many degrees , but it really improves bottom end response, & spool.
now if my back would let me straighten up, I'd be back to where I was about a week ago.
marc
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FirstFives Dictator
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paul burke
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paul burke
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Re: MS MAP Signal - Lesson Learned the hard way!
T_C_D wrote:
Hit the hwy for another pull and saw 13-13.5psi on both the boost gauge and MS. Idle now at 38-40kpa instead of 43-45kpa. Seems the silicone hose deteriorated enough in 6 months to cause a poor signal to MS.
Paul
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marc79euro645
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Joined: 08 Sep 2008
PostPosted: Oct 02, 2011 3:27 PM Post subject: Reply with quote
Shadow wrote:
What gear do you have that slipped?
I'm wondering what sprocket he has also?
Paul
I have an original bmw cam sprocket that has been slotted for about 5* of adjustment. my mistake thinking the 4 bolts with washers would hold under torque.
marc
PostPosted: Oct 02, 2011 3:27 PM Post subject: Reply with quote
Shadow wrote:
What gear do you have that slipped?
I'm wondering what sprocket he has also?
Paul
I have an original bmw cam sprocket that has been slotted for about 5* of adjustment. my mistake thinking the 4 bolts with washers would hold under torque.
marc
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paul burke
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They will.marc79euro645 wrote:Joined: 08 Sep 2008
PostPosted: Oct 02, 2011 3:27 PM Post subject: Reply with quote
Shadow wrote:
What gear do you have that slipped?
I'm wondering what sprocket he has also?
Paul
I have an original bmw cam sprocket that has been slotted for about 5* of adjustment. my mistake thinking the 4 bolts with washers would hold under torque.
marc
Must have had some other issue causing this, soft bolts, not tight enough from the get go?
If you study the factory M50,S50/52 method, not only are the sprockets slotted with no dowel they are also sandwiched and have a smaller bolt diameter.
Paul
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FirstFives Dictator
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You need to be honest. You said that you thought there may be an issue with where the signal originated not how it was delivered.FirstFives Dictator wrote:Fixed for youT_C_D wrote:If you were any good you would have convinced me it 60 days ago when I disagreed with you!FirstFives Dictator wrote:You're welcome, Todd.
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FirstFives Dictator
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True but I'm pretty sure I warned you about cheap silicone hosesT_C_D wrote:You need to be honest. You said that you thought there may be an issue with where the signal originated not how it was delivered.FirstFives Dictator wrote:Fixed for youT_C_D wrote:If you were any good you would have convinced me it 60 days ago when I disagreed with you!FirstFives Dictator wrote:You're welcome, Todd.