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-   -   330 Engine hesitation at cornering limits (http://forum.e46fanatics.com/showthread.php?t=483)

Salsero 04-13-2002 01:26 PM

Track,Tech guys-330 Engine hesitation at cornering limits
 
Anyone seen this before?

While driving my car near limits of adhesion (as in a skidpad) the engine hesitates. Applying more tnrottle yields no more power. It almost feels as if engine rolls back to idle.

This happend with DSC switched off. By the way, holding DSC button for 5 seconds does nothing. This also happened to another guy with an early 2001.

Car runs normal under all other conditions. Only seems to happen under hard prolonged cornering.

njsign 04-13-2002 04:30 PM

Can't say I've noticed this. I've done quite a bit of autocrossing (on both street and race tires) and aggressive testing in closed parking lots and have never had power "cut-out" when DSC disabled. I also have an early 2001 model (August build I believe) and don't have the two stage DSC control.
I spoke with the head tech at my local BMW dealership and was told that, with the earlier models, the "traction control" is either completely on or completely off with the press of the button. This means that the DSC's functions of CBC (corner brake control) and ADB (Automatic Differential Braking) are both "off" leaving only ABS active. With the newer systems pressing the button once turns off ADB, the second time (while holding button for 5+ seconds) turns off CBC.
I'd suspect there is a glitch that doesn't allow the CBC to be disabled. I'd take it to the dealer and see if any fault codes come up on the computer.

John from jersey 04-13-2002 05:07 PM

whether u have DSC on etc... it is normal for the E46 3er

Here is a way to improve on that problem



//www.uucmotorwerks.com/flywheel/LFWLE46.htm/

Salsero 04-13-2002 06:08 PM

....njsign, John from jersey
 
Hey guys,

Thanks for the info.

njsign- I am going to pursue w/ dealer.

John from jersey- you think LWFW will help this? To me it feels like DSC interference. However it sounds like you are familiar with problem. Can you tell me cause and how UUC FW will help?

Thanks

John from jersey 04-13-2002 06:29 PM

Re: ....njsign, John from jersey
 
Quote:

Originally posted by Salsero


John from jersey- you think LWFW will help this? To me it feels like DSC interference. However it sounds like you are familiar with problem. Can you tell me cause and how UUC FW will help?

Thanks

Im familiar in a sense, I know what you are referring to. I use to drive an E46 3er...so what u describe seems to be what i have experienced.

If you have bypassed the DSC completely, which is done by holdin the DSC button down for 10 secs or so.
If its your DSC interfering wouldnt the light flash on your dash alerting you that is the DSC working? It should ...so i concluded you are having throttle hesitation. And yes my suggestion up above will improve greatly on this. A freind of mine drives a 330cic with this installed and loves it..Seems to have great results due to it

U may want to try an email him if he doesnt respond to this thread bimmerspeed@aol.com. For first hand impressions on the UUC Lightweight Flywheel

Samir 04-13-2002 08:46 PM

The DSC never fully disengages, it's always active even when switched off...just set to a less intrusive setting. To fully disengage, you need to pull the DSC fuse...a few M5 owners had to resort to this to properly dyno their cars.

njsign 04-13-2002 08:47 PM

Throttle being "cut-out" during its application has NOTHING to do with the weight of your flywheel and it is not normal when the DCS functions are disengaged.
The flywheel won't make the situation better. When power is lessened it is because of a change the computer makes to the spark and fuel delivery.
Changing to a lightweight flywheel will make matters worse when power is cut-out as it will make the car slow down even quicker. You'd have better results changing your dead pedal. :smile:

Again, not all e46 models have the "two-stage" (on or off) DSC button.

njsign 04-13-2002 09:07 PM

Samir -

Do the non-M 3 series cars have the M5's "virtual dry sump?"

Perhaps the DSC isn't completely disengaged in the M5 because they tell the "virtual dry sump" motors to activate?

Also, which fuse would I have to pull in a 330ci? Are their any ramifications to this? I'm going autocrossing again tomorrow and I'll mess with it if you don't think it'll leave me stranded 90 minutes from home.....

Samir 04-13-2002 09:24 PM

Do the non-M 3 series cars have the M5's "virtual dry sump?"

The 330 has a semi-dry oil sump

Perhaps the DSC isn't completely disengaged in the M5 because they tell the "virtual dry sump" motors to activate?

I'm not sure if the DSC relays any information to the DME in regards to sump activation...the DME uses g sensors to control the sump

Also, which fuse would I have to pull in a 330ci? Are their any ramifications to this? I'm going autocrossing again tomorrow and I'll mess with it if you don't think it'll leave me stranded 90 minutes from home.....

I don't want to recommend anything that I have not personally fiddled with. I'm not exactly sure which fuse it is, but you can find it on the fuse box cover. In theory it should not hurt anything (you're merely disengaging a fuse) so I wouldn't worry about being stranded, but this is how a few people have gotten around the DSC.

John from jersey 04-13-2002 09:50 PM

Quote:

Originally posted by njsign
Throttle being "cut-out" during its application has NOTHING to do with the weight of your flywheel and it is not normal when the DCS functions are disengaged.
The flywheel won't make the situation better. When power is lessened it is because of a change the computer makes to the spark and fuel delivery.
Changing to a lightweight flywheel will make matters worse when power is cut-out as it will make the car slow down even quicker. You'd have better results changing your dead pedal. :smile:

Again, not all e46 models have the "two-stage" (on or off) DSC button.


if u read his post it says "hesitation" not "cut-out" i think we are talking about two different things here...

I doubt a LTW would make "matters worse"

it is a review of the Rogue LTW which is comparable to the UUC LTW

Here is a review i found on DTM:

This past Saturday, I also had the Rogue Engineering LTW flywheel installed on my car. (Thanks a million again to those that helped!!!) The stock unit weighed in at 24lbs (with the bolts) while the RE unit weighed in at 14lbs (with the bolts) using a simple package scale. Although not the most accurate of measuring instruments, it gave me an idea of the weight savings the RE LTW Flywheel would give over the stock piece - around 10lbs.

The E46 (at least with a manual transmission) is known to have a distinct throttle response hesitation. It isn't very discernible to the regular driver but I think most of the E46 enthusiasts here know what I'm talking about.

But for those unfamiliar with this quirk, let me elaborate. When you press the throttle, there is a fraction of a second that goes by before the drivetrain actually responds. This can be extremely annoying and restricting when trying to run through the gears rapidly (as one might do on a track).

Despite the fact that our cars are drive-by-wire (meaning the throttle activation is computer controlled), the Rogue Engineering LTW flywheel is supposed to eliminate the hesitation and allow quicker acceleration. Many of you are probably wondering, "How is that possible?" Now, I'm not a mechanical engineer by any means so I'm not even going to attempt to try and explain how or why it works. That's not what my review is about. I am here to just give my impressions.

The throttle hesitation is GONE. Plain and simple. I press the throttle and the car just GOES. No more of that "throttle down.................then GO". Now it's "throttle downGO". I don't think I need to say anything else about that.

Now for the quicker acceleration. I don't have any measured numbers but I do have some good ol' butt dyno reactions. It definitely feels like it's quicker off the line. And logically, it makes sense that it would be since the drivetrain responds better with it. It definitely reaches the upper RPMs much faster. I find myself having to shift into higher gears earlier then I'm used to.

For those familiar with flywheels, one question remains in your minds right now. How loud is it? Actually, it's not very loud at all. It's quieter then some of the E36 M3 versions I've heard. But it's definitely not anything you'd really care about once you feel the results.

Overall, in the two days I've been driving around with it, I am extremely pleased (that could very well be the understatement of the year). The car moves like it has been unleashed.

For all of those looking to gain some edge at the track, this is a great way to do it. And for those looking to just make your car "faster", you cannot go wrong with the RE LTW Flywheel. I would recommend it wholeheartedly and unabashedly.

The only downside is that I've been using a LOT of gas just to keep feeling how quickly the car responds now! LOL!

KevinJ_2k1_325ci 04-13-2002 11:12 PM

I actually had this hesitation problem last week. I have a 2001 325ci with Steptronic. I was at a stop light which is on about a 8% incline waiting to turn right. I floored it trying to beat traffic with DSC OFF and the car sputtered, it was like puh puh puh puh . . . . varooom. Almost like the fuel supply was being cut off or the tranny slipped. I hit kick down and it still sputtered and picked up speed very very slowly. I've also had this sort of problem on the highway which was very dangerous around the Washington DC area. I was trying to pass a car in front of me and a truck was in the left lane about 20 car lengths away. When I switched lanes and floored it, the car went no where and the truck almost ran me over. I have a 9 month old kid in the back so it wasnt funny at all. I'm starting to wonder if my transmission is bad or the software is acting funny. I'm fearful that the dealer will say well we test drove it and its fine like they always do and I'll have to wait till Im in an accident to prove it.

KevinJ_2k1_325ci 04-13-2002 11:17 PM

Oh also had DSC kick in with DSC was and brake was off!
 
I also had DSC and brake off and made a U-turn and DSC kicked in! I think BMW's software is f'd up. When is the damn Shark Injector coming for the 325/330. Damn is he waiting to release it when the 4 series is out in 2005/2006 or something.

Salsero 04-14-2002 01:36 AM

njsign, John from j- you are both right
 
John from j - I feel that hesitation you are talking about..it is a drag. Thanks for the info...will consider that FW.

In this case, it is a hesitation as in IT WONT GO! Feels like severe spark retardation or fuel starvation. Apply more throttle and it barely comes above idle. If you had to avoid traffic, you would have to get out and push it.

I think we are talking DSC Nazis here. BMW has a software quirk!
My theory: At such big slip angles (yaw) the yaw sensor inputs totally overwhelm the system and it just shuts everything down.

Young 04-14-2002 02:46 AM

I don't think anyone has asked the obvious question...how much gas did you have in your tank? As someone mentioned, you may be experiencing fuel starvation. I've experienced it under heavy cornering at a racetrack with just about a quarter of a tank of gas in my 330i. I now make sure to go out on track with at least half a tank.

njsign 04-14-2002 03:55 PM

Samir-
I'm not sure if the DSC relays any information to the DME in regards to sump activation...the DME uses g sensors to control the sump
Here's something I found on the web....
So what they did do was say, "Okay, we will virtually dry sump this," and they put two motors into the engine, which, are triggered by the DSC (the Dynamic Stability Control) electronic transistor units that send messages to say how fast the car is going around the corner. The DSC units switch these little electric motors on and they pump the oil out of the engine banks. Thatís a sort of example of practical and clever engineering that makes a BMW different.
I don't know how true it is....

I understand. I'll fiddle with the fuses. :smile:

John-
Salsero has since clarified the term hesitation as meaning "it won't go!," "Feels like severe spark retardation or fuel starvation."
As such, or in any case, if you are attempting to at least maintain your momentum through a turn while not being on the throttle the lightweight flywheel will slow your car down more quickly than the heavyweight stock flywheel. The LFW allows the motor to "wind down" as quickly as it "winds up."
I don't disagree with the advantages of a LWF that you've pointed out. It will certainly increase the engine's responsiveness to throttle application. I've driven a race prepped car with a lightweight flywheel......you could practically sneeze on the gas pedal and make the rpms rise.

Kevin-
I'd definately have that checked out. Perhaps my "old" 5-speed 330 has a different program but I've never encountered that situation myself.

Young-
Good question!

Salsero-
What size and type of tires were you using on the skidpad?

Salsero 04-14-2002 04:38 PM

.....tires
 
I am running the stock 330 SP Continentals.

Salsero 04-14-2002 08:06 PM

young.....
 
You said you have experienced fuel starvation under hard cornering--do you remember the approx fuel level?

Did it happen more than once? Has higher tank level solved the problem? In other words, can you go into a corner agressively w/o cut-out?

If this does turn out to be a fuel prob instead of DSC, that would be a drag. You would think BMW would be way beyond fuel baffle or fuel system supply problems.


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