Quiet Moments.....with Jim Conforti - Addressal of the 4k Power Dip

[danewilson77]

I am posting this for 3 reasons:

1. My dip is still prelevant at approximately 4k rpm.

2. I just got off the phone with Jim Conforti.

3. I wanted to share the info....with the Family.

He spoke with me for roughly an hour. It was an interesting discussion...that entailed training on DISA valve operations, adiabatic ignition, the 4k power dip, software tuning, Ferrari's, gasoline quality, NORAD and what his future holds.

With regard to the 4k power dip.....his impression is - As told by me (I need to remind you guys....that he only comes on the boards and says something....if he has run the numbers himself and has verified it to be true): I will never say it like he does, as he was feeding me knowledge from a fire hose. Basically there are two phenomina that contribute to the 4k Power dip:

1. Mechanical sticking / Operation of the DISA. This is normal operation.....as rpm's increase to a point (3750 rpm's) the DISA valve slams open. There is no slow progession through that "dipped" power range.

2. Knock sensor adaptations, regarding DISA. He has disabled the DISA in cars that he has supercharged. This did result in a bit of torque loss in that power range, but the car operated overall, smoother and more efficient with zero power dip. As far as he knows, tuning will not remove the dip. Tuning may reset the adaptaion values, so initially, the dip will not be there (or be less prevalent), but after fuel management system adapts to new limits, the dip will be back. I think this is the case for me. He additionally said altering the knock sensor adaptations on a street driven car was suicide.

As an aside.....we had an interesting gasoline discussion. He said that 91 octane from Sinclair (or any other gas station for that matter) and 91 octane from Shell, with equal RM values, will not be the same gas. Mind blown.

So.....if you couple a tune (that alters the knocks sensors), with a tank of gas.....other than Shell....melting a hole in your piston, could occur. Interesting statement here. For this sole reason, when he was performing dyno's, he instructed customers to only fill up at a Shell, near the dyno shop (Then followed and interesting story about a kid not following these orders, which resulted in Jim chasing his tail for 5 hours on the dyno, and resulted in a full drain and purge of the cars fuel delivery system)

So....in a nutshell.....there is no, known fix.....in his opinion, for the dip. Remember...there's 2 issues here. One is mechanical. One is electrical.

As a favor to me (and the community), he will be asking his contacts at BMW, if they have addressed this issue with a fix yet.

When he replies to my email....I will post here, or he'll come on and update the thread with his thoughts and findings.

Jim...I apologize in advance for butchering what you told me on the phone. You were shifting gears pretty fast......between a myriad of topics, and I could not fully wrap my head around some of the concepts. At this point....I hope all is well with you, and I appreciate you taking my phone call.

~DW

[Marcus-SanDiego]

Jim ftw.

Thanks for the Cliff's Notes version, dw.


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[Newjack]

Thanks for the info DW. I'm curious about those who have sent their DME to NJ to have the dip "fixed". I'm guessing it wasn't a permanent fix then, and simply made it less noticeable by changing the adaption values?

Also, any more specifics on the Chevron gas? Getting Chevron is better for your engine, (Safer) not necessarily better for power?

[Johal E32]

thanks for the info!

-I used to own a few gas stations awhile back and I agree Chevron gas is great (It's what we used to sell). However, Arco gas is simply crap. Seriously, don't be intrigued by their cheap prices..

[Oli77]

What would happen if you removed the flap in the DISA on a non supercharged car? Less torque at lower rmps?

[danewilson77]

What would happen if you removed the flap in the DISA on a non supercharged car? Less torque at lower rmps?
Yup. And it won't remove the dip. It will just move the dip. Another thing he mentioned to me was that you can make the power curve perfectly smooth, but the dip would still be there. I didn't totally get this.

Sent from SIGFest 2012, via TTv1.5.4

[Newjack]

Yup. And it won't remove the dip. It will just move the dip. Another thing he mentioned to me was that you can make the power curve perfectly smooth, but the dip would still be there. I didn't totally get this.

Sent from SIGFest 2012, via TTv1.5.4

Take that power dip, and stretch it across a much much wider rpm range to decrease what is felt (doesn't seem like the dip is there) but it is still there. :dunno

[Johnmadd]

Good stuff dw. My cars po had software fix from the nj headquarters, I don't notice a dip. Dane, I should let you drive mine to see what you think, what do you think about that?

[danewilson77]

Good stuff dw. My cars po had software fix from the nj headquarters, I don't notice a dip. Dane, I should let you drive mine to see what you think, what do you think about that?

I think I like it.

Sent from SIGFest 2012, via TTv1.5.4

[Johnmadd]

I think I like it.

Sent from SIGFest 2012, via TTv1.5.4

Pm me. Sunday at 14:00 sound good?

[Oli77]

I've always though driving each others car would be a good idea.

[zhpnsnv]

I got the reflash from BMW and it fixed the dip for a long time. I now notice it only once per drive then it goes away. I have my adaptations reset every trip to the dealer. No chevrons here so I use shell 93 whenever possible.

[danewilson77]

I got the reflash from BMW and it fixed the dip for a long time. I now notice it only once per drive then it goes away. I have my adaptations reset every trip to the dealer. No chevrons here so I use shell 93 whenever possible.

OK... Great. I honestly think the "gas discussion" we had was only applicable, regarding engine damage, if you had a tune that altered the knock sensors.

Sent from SIGFest 2012, via TTv1.5.4

[ranger]

I have been thinking about this dip issue. Mine is most prevalent (2005 6MT ZHP) in 3rd gear under heavy load (accelerating uphill) at 3500 rpm.

[danewilson77]

Pm me. Sunday at 14:00 sound good?

Gotta work till 1700....maybe we can hook up next week.

Sent from SIGFest 2012, via TTv1.5.4

[MrMaico]

I got the reflash from BMW and it fixed the dip for a long time. I now notice it only once per drive then it goes away. I have my adaptations reset every trip to the dealer. No chevrons here so I use shell 93 whenever possible.

I've noticed that some people who have had their DME sent to Jersey for the fix say it was cured and others say it was cured for a while then came back. Yours sounds like a mix of the two. It sounds like your knock sensors adjust for the sound of the Disa opening once and then they catch it before the dip happens for the rest of that drive cycle. That's assuming it's the knock sensors adjusting timing that causes the dip.

My Disa was replaced when I bought my car in August 09 so I'd assume it's the newer version. Mine is just a very slight hesitation at 4000 but I haven't noticed if it does it more than once a drive, I'll have to pay closer attention next time.


I have been thinking about this dip issue. Mine is most prevalent (2005 6MT ZHP) in 3rd gear under heavy load (accelerating uphill) at 3500 rpm.

Have you ever had a DME update at a dealer or indy? Not talking about the 4000 dip update where they send it to Jersey, just the latest software update.

If yours was at 2800 rather than 3500 I'd say you need the software update for sure but maybe yours just reacts at a different rpm than mine and a lot of others do/did. Does it do it in higher gears too or just 3rd?

Barry

[danewilson77]

I bought brand new DISA in Aug/Sep 2010 just after buying car. I will have to see if it's the upgraded P/N.

Additionally, Jim put the Shark and BMW updated software on my ECU.

[ranger]

I have been thinking about this dip issue. Mine is most prevalent (2005 6MT ZHP) in 3rd gear under heavy load (accelerating uphill) at 3500 rpm.

I bought the car used at 102,000 miles - I do not think the DME was ever "updated" by previous owner and I have not dealt with it yet. Sounds crazy but it always seem to be in 3rd gear when I get the stumble.

[Johnmadd]

Gotta work till 1700....maybe we can hook up next week.

Sent from SIGFest 2012, via TTv1.5.4

Sounds good.

[aurelius]

DW requested I copy the following post from another thread:


Originally Posted by Meric (http://www.zhpmafia.com/forums/showthread.php?p=170809)
Yea I never felt the dip. Yet this is my second e46..Only affects those with manual transmission.


Originally Posted by danewilson77 (http://www.zhpmafia.com/forums/showthread.php?p=170764)
Many......myself included....are leaning toward the DISA vlave as being the issue with the dip.At least initially, BMW thought so too and they were replacing DISA as part of the solution.

But as of 2005, their solution is reprogramming. CLICK HERE (http://dl.dropbox.com/u/17676561/BMW%20docs/SIB%2012%2017%2005%20%284k%20RPM%20power%20dip-DISA%20valve%29.pdf) to see the latest Service Information Bulletin on this topic.

What I wonder is if the updated DISA design alone (11617544805) would solve the problem without all the hassle of sending the DME off to the "Engineering Dept."

Worth noting for those who have not read about these issues ad nauseam: this symptom is not seen on all M54 motors and is totally separate from the 2800 RPM hesitation, which can be addressed at a dealer or indie shop with the right equipment (autologic). See latest software versions in autologic screen shot below. Applies to man-trans M54 motor with the ZHP cams. I do not know if these version numbers apply to all 3.0L M54 motors but hooking up to autologic or dealership service computer will tell you if yours needs updating.

FWIW, I can testify switching from BMW 5W-30 to OW-40 motor oil will noticeably reduce the 2800 RPM hesitation. Even more so with high-end oil. I was not expecting this at all but it was noticeable when I switched to Mobil 1 OW-40 and then more so with a switch to Lubro Moly OW-40. Others have reported similar findings.

This screen shot was taken April 10, 2012:

http://i1125.photobucket.com/albums/l584/aurelius3/Random%20BMW%20Pics/DMEversion12-04-10.jpg

[Oli77]

So tell me, is it only the ZHPs that have this dip thing around 4 K rmp?

[aurelius]

Download the SIB linked in my post above.

A few M54-equipped models are affected, E46 and others. Early E60 530i, early Gen 1 Z4 3.0.

3.0L M54 only, not the 2.5L. And man-trans only.

[danewilson77]

So tell me, is it only the ZHPs that have this dip thing around 4 K rmp?

According to Jim, it's only cars with MS45 software... But apparently SIB says otherwise.

Sent from SIGFest 2012, via TTv1.5.4

[MrMaico]

I bought the car used at 102,000 miles - I do not think the DME was ever "updated" by previous owner and I have not dealt with it yet. Sounds crazy but it always seem to be in 3rd gear when I get the stumble.

On mine it did it in 3rd too but it was more noticeable under acceleration in 4th, 5th and 6th. And like you said, more noticeable going up a hill, or even into a good headwind. I assume it might have done it in the lower gears too but the engine ran through that 2800 to 3000 rpm range so quick that you just didn't notice it.

[Oli77]

I have M54B25.

Assuming I am spared from the dip blues according to that SIB.

[danewilson77]

You should be un-affected Oli.

What it says to me...in a nut shell is......"blah, blah, blah....you're going to be without your car for a month, blah, blah, blah....."

I've copied the SIB here....

This Service Information bulletin supersedes S.M. B12 209 05 dated 4/6/2005.

SUBJECT
M54B30 MS45.1; Engine Power Drops at 4000 RPM

MODEL
E46, E60, E85 with M54B30 engine and manual transmission only

SITUATION
The customer may complain of an engine power drop at approximately 4000 RPM during aggressive
acceleration.

CAUSE
Ignition timing retardation shift due to unfavorable knock adaptations in the 4000 – 5000 RPM range.

CORRECTION
On a customer complaint basis, perform the procedure described below.

PROCEDURE
1. Verify the complaint. This situation can vary from a slight surge to a noticeable drop in power
during hard acceleration.

2. Do not replace any parts!

3. Submit a PuMA case requesting authorization for DME shipment to Engineering Department for
reprogramming. For the PuMA case title please use the following: "MS45.1 DME KNOCK
ADAPTATION RESET".

4. Reinstall the DME.

5. For E60 only: Reprogram the vehicle using CIP 19.1 (Target Data Status E060-05-09-530), or
higher.

WARRANTY
Covered under the terms of the BMW New Vehicle Limited Warranty.
For the appropriate labor operations please refer to the KSD system.

SI B 12 17 05
Engine Electrical Systems
September 2005
Technical Service
[ Copyright © 2005 BMW of North America, LLC ]
Page 1 of 1
http://www.bmwtechinfo.com/tiscode/cgi-bin/omcgi.exe?sie_path=/tsb/bulletins/htm_store... 10/9/2005

[terraphantm]

I suspect the only reason it says to send the DME to Jersey is because the SIB is so old (fix might not have been rolled out by that point). Unless there's a hardware change, I don't see why flashing the software in-house would be an issue. Latest software is circa 2008. On my old ZHP it did nearly eliminate the 4k dip issue (well it was detectable on a dyno, but every 330 has that)

I would like to see what a Jersey-flashed DME reports itself as. If it's the same hardware/software that dealers can flash in-house today, then there's probably no real benefit from having it sent to Jersey and paying $500+

[UdubBadger]

damn good info

[derbo]

I suspect the only reason it says to send the DME to Jersey is because the SIB is so old (fix might not have been rolled out by that point). Unless there's a hardware change, I don't see why flashing the software in-house would be an issue. Latest software is circa 2008. On my old ZHP it did nearly eliminate the 4k dip issue (well it was detectable on a dyno, but every 330 has that)

I would like to see what a Jersey-flashed DME reports itself as. If it's the same hardware/software that dealers can flash in-house today, then there's probably no real benefit from having it sent to Jersey and paying $500+


I'm not sure why it needs a PUMA case and sent to BMW NA for programming but I did have it done and I'm uncertain of many things it did. it supposedly removed the dip from 3k but I also noticed my DISA Valve is now always open when the car is running.

Whad do you mean how it reports itself? I have the DME updated so what information would you like me to pull? I can try and pull it off at work.

[aurelius]

I'm not sure why it needs a PUMA case and sent to BMW NA for programming but I did have it done.....

Meaning yours was sent to NJ or just re-flashed at the dealership?

[derbo]

Meaning yours was sent to NJ or just re-flashed at the dealership?

It was sent to NJ for reflashing. It took 2days for the DME to be reflashed.

https://img.skitch.com/20120509-py99xqaaxmyrg141f344247tjh.png

[aurelius]

I think I'd rather have the updated DISA, which is what BMW was replacing per the initial SIB.

[Smolck]

I was doing some more research on this as my car was reprogrammed and the dip has come back. It is still pretty bad. When my car hits 4k rpm you feel it die off bad and then when you hit 5k rpm you feel it pick up hard again. The ONLY time it doesn't do it is when the car is just warming up in the morning. Since your fuel curve is fatter during warm up this means the 4k rpm dip is coming from a LEAN condition in the engine.

To make matters worse I had a friend of mine at BMW order me the newest DISA to try it out. It improved everything significantly, but didn't eliminate it. For the $200 I decided to try other things before keeping it. Talk about annoying. My friend has an 01 330ci and it has no dip to speak of, why is my "special" car damned to this inferior performance?

[danewilson77]

Good info Smolck.

Delivered from SIGFest USA

[WOLFN8TR]

I bought brand new DISA in Aug/Sep 2010 just after buying car. I will have to see if it's the upgraded P/N.

Additionally, Jim put the Shark and BMW updated software on my ECU.

Dane what was the cost to have Jim do this? What was the turn around time?

[danewilson77]

The turn around was the 1st day I shipped it overnight, the 2nd day he programmed it and overnighted it back to me, then I got it back the third day.

Shipping dme to Jim is not a typical situation.

[aurelius]

Came across DISA image and info below in a very long performance M54 engine build thread HERE (http://forums.my330i.com/showthread.php?p=55148).



http://i1125.photobucket.com/albums/l584/aurelius3/Random%20BMW%20Pics/file.jpg

[Hornung418]

One if the most famous e46s ever. Adam is a huge influence on the track crowd.

Horney...via TT.

[Banderson8288]

I updated my dme with winkfp in about 20 min no more hesitation 2.5k-32k rpm and no 4k power dip and a lil better gas mileage as well. Works great!!!!!

[Banderson8288]

If anyone is in Florida I can update dme in about 20-30 min.

[danewilson77]

If anyone is in Florida I can update dme in about 20-30 min.

Awesome. Thanks for offering.

Fwiw...we have debated this quite a bit, so I'm interested in the longevity of the software fix. It has been said on numerous occasions, that the dip will come back, over a period of time, after software update. How long has it been since your update?

Keep us filled in. Thanks.

Sent from Williamsburg, VA USA

[danewilson77]

I am posting this for 3 reasons:

1. My dip is still prelevant at approximately 4k rpm.

2. I just got off the phone with Jim Conforti.

3. I wanted to share the info....with the Family.

He spoke with me for roughly an hour. It was an interesting discussion...that entailed training on DISA valve operations, adiabatic ignition, the 4k power dip, software tuning, Ferrari's, gasoline quality, NORAD and what his future holds.

With regard to the 4k power dip.....his impression is - As told by me (I need to remind you guys....that he only comes on the boards and says something....if he has run the numbers himself and has verified it to be true): I will never say it like he does, as he was feeding me knowledge from a fire hose. Basically there are two phenomina that contribute to the 4k Power dip:

1. Mechanical sticking / Operation of the DISA. This is normal operation.....as rpm's increase to a point (3750 rpm's) the DISA valve slams open. There is no slow progession through that "dipped" power range.

2. Knock sensor adaptations, regarding DISA. He has disabled the DISA in cars that he has supercharged. This did result in a bit of torque loss in that power range, but the car operated overall, smoother and more efficient with zero power dip. As far as he knows, tuning will not remove the dip. Tuning may reset the adaptaion values, so initially, the dip will not be there (or be less prevalent), but after fuel management system adapts to new limits, the dip will be back. I think this is the case for me. He additionally said altering the knock sensor adaptations on a street driven car was suicide.

As an aside.....we had an interesting gasoline discussion. He said that 91 octane from Sinclair (or any other gas station for that matter) and 91 octane from Chevron, with equal RM values, will not be the same gas. Mind blown.

So.....if you couple a tune (that alters the knocks sensors), with a tank of gas.....other than Chevron....melting a hole in your piston, could occur. Interesting statement here. For this sole reason, when he was performing dyno's, he instructed customers to only fill up at a Chevron, near the dyno shop (Then followed and interesting story about a kid not following these orders, which resulted in Jim chasing his tail for 5 hours on the dyno, and resulted in a full drain and purge of the cars fuel delivery system)

So....in a nutshell.....there is no, known fix.....in his opinion, for the dip. Remember...there's 2 issues here. One is mechanical. One is electrical.

As a favor to me (and the community), he will be asking his contacts at BMW, if they have addressed this issue with a fix yet.

When he replies to my email....I will post here, or he'll come on and update the thread with his thoughts and findings.

Jim...I apologize in advance for butchering what you told me on the phone. You were shifting gears pretty fast......between a myriad of topics, and I could not fully wrap my head around some of the concepts. At this point....I hope all is well with you, and I appreciate you taking my phone call.

~DW

Bumping for Jim.

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[terraphantm]

For anyone who is uncomfortable updating the DME themselves and doesn't want to pay the dealer rates, I can flash it on my bench if you mail it to me.

[330i ZHP]

The DISA being a problem makes sense - since I do not have one and do not have the dip. But I do remember it from when the ZHP was NON-FI

[derbo]

The DISA being a problem makes sense - since I do not have one and do not have the dip. But I do remember it from when the ZHP was NON-FI

Did you just put a block off plate?


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[BCS_ZHP]

Stuart's "Wagone" is supercharged, a whole new & different intake manifold set-up.

Plus recall the intended job of the DISA. At rpms below 3750-4000, it stays closed so that your air-fuel mixture is only traveling thru half of the volume of the intake manifold - some a/f traveling to the front 3 cylinders and the remainder traveling to the rear 3 cylinders. Above that rpm level the engine needs a/f quicker, the DISA opens so that the air-fuel is being fed as fast as it can be, you're trying to get power at that point so efficiency isn't the main goal. On Stuart's set-up, you're compressing & forcing air/fuel into the engine all the time, the faster the s/c spins the more a/f it compresses and sends to the engine.

[330i ZHP]

Well said

[Hermes]

every time I see this thread I think of Deep Thoughts with Jack Handey

[GreatFrog]

OK... Great. I honestly think the "gas discussion" we had was only applicable, regarding engine damage, if you had a tune that altered the knock sensors.

Sent from SIGFest 2012, via TTv1.5.4

So it is not applicable to Shark Injector? I cheap out on Kroger's fuel all the time ever since I discovered the $1.00/gal off trick :eeps. Was a loyal Shell customer before that... I googled around before switching, people were saying the base fuel is the same for all local gas stations, the difference is in the additives. Especially intriguing given the fuel point partnership between Kroger and Shell.

[danewilson77]

So it is not applicable to Shark Injector? I cheap out on Kroger's fuel all the time ever since I discovered the $1.00/gal off trick :eeps. Was a loyal Shell customer before that... I googled around before switching, people were saying the base oil is the same for all local gas stations, the difference is in the additives. Especially intriguing given the fuel point partnership between Kroger and Shell.
I think it is applicable to any tune. He was very exacting and descriptive in his explanation of the beautiful blue and quality of flame at the spark. I don't think cheap gas saves you enough to justify it imo.

Sent by the Pixel XL

[GreatFrog]

I think it is applicable to any tune. He was very exacting and descriptive in his explanation of the beautiful blue and quality of flame at the spark. I don't think cheap gas saves you enough to justify it imo.

Sent by the Pixel XL

Thanks Dane. Just needed another excuse to switch back to Shell :thumbup.

My pathetic Mazda 3 can keep drinking discounted Kroger fuel without complaining :p

[danewilson77]

I think it is applicable to any tune. He was very exacting and descriptive in his explanation of the beautiful blue and quality of flame at the spark. I don't think cheap gas saves you enough to justify it imo.

Sent by the Pixel XL
And BTW... Not flame at the "spark". Flame in the combustion chamber/cylinders.

Thanks Dane. Just needed another excuse to switch back to Shell [emoji106].

My pathetic Mazda 3 can keep drinking discounted Kroger fuel without complaining :p


Sent by the Pixel XL

[A1Gio2]

Interesting information...I'm not sure its worth the DME flash.

My car has 55k miles and has the 4-5k rpm dip. After reading this, it might be best to just wait until the DISA valve needs replacing and hoping that it rectifies the problem. I'm not worried about the cost of the flash, but more so the longevity of the motor and messing with knock adaptations.