|
|
|
|
|
|
BMW Garage | BMW Meets | Register | Today's Posts | Search |
|
BMW 3-Series (E90 E92) Forum
>
stock DME load limits hindering piggyback potential?
|
|
01-17-2011, 12:12 PM | #89 | |
Banned
6
Rep 348
Posts |
Quote:
|
|
Appreciate
0
|
01-17-2011, 12:26 PM | #90 | |
Second Lieutenant
6
Rep 291
Posts |
Quote:
If you don't know, the stock tuning tries to maintain power under varying conditions. As it gets hotter, the DME actually raises boost to maintain 300hp. This is a fundamental feature of the DME architecture. It is designed for consistency, not maximum power. The piggybacks take control of boost, fuel, etc. with the goal of maximum performance for the conditions, not consistency. You will make less power on hot days, and more power on cold days. Same is true with varying fuel quality. Changing how the DME works is simply not as simple as reflashing the DME to resize and tune existing tables.
__________________
2009 Spacegrau 335i |
|
Appreciate
0
|
01-17-2011, 12:32 PM | #91 | |
Second Lieutenant
6
Rep 291
Posts |
Quote:
That is fine. But for those that want to run the maximum possible performance, methanol is required. Personally, I share your reluctance to run meth. I'd be ecstatic with 400whp with a tune and bolt ons with 93oct and more if I want to run racegas.
__________________
2009 Spacegrau 335i |
|
Appreciate
0
|
01-17-2011, 12:32 PM | #92 |
Brigadier General
161
Rep 3,736
Posts |
Piggy's have proven to be the fastest at the track, low to mid 11's in the quarter mile with 120+mph traps so I don't think there is much to this..
|
Appreciate
0
|
01-17-2011, 12:33 PM | #93 | |
Brigadier General
102
Rep 3,460
Posts |
Quote:
|
|
Appreciate
0
|
01-17-2011, 12:35 PM | #94 |
Banned
6
Rep 348
Posts |
It should also be mentioned the even the stock tune will knock, just as my as any flash can knock. There is no perfect solution unless your tuned extremely conservative. STI/EVo etc all knock stock as well. The best thing you can do is limit the amount of knock and have a process to determine a happy medium. I think the stock DME logic is ass-backwards but thats cause im used to tuning stand-alone systems.
|
Appreciate
0
|
01-17-2011, 12:46 PM | #95 | |
Second Lieutenant
6
Rep 291
Posts |
Quote:
Maybe you should read this: http://www.e90post.com/forums/showthread.php?t=345306
__________________
2009 Spacegrau 335i |
|
Appreciate
0
|
01-17-2011, 12:54 PM | #96 | |
Second Lieutenant
6
Rep 291
Posts |
Quote:
This the main reason I think autotuned piggies are superior at this point. They will give you the maximum safe tune all the time for the specific conditions your engine is under. Not just the conditions when you were on the dyno being protuned...
__________________
2009 Spacegrau 335i |
|
Appreciate
0
|
01-17-2011, 01:12 PM | #97 | |
Banned
6
Rep 348
Posts |
Quote:
Its the ignition timing is conservative enough, it might have enough play. It will respond like the factory DME and cut back ignition from what i understand. |
|
Appreciate
0
|
01-17-2011, 01:15 PM | #98 | |
Joint Chiefs of Staff
4918
Rep 115,980
Posts |
Quote:
Mike |
|
Appreciate
0
|
01-17-2011, 01:32 PM | #99 | |
1737
Rep 17,960
Posts
Drives: A Lot
Join Date: Sep 2006
Location: SF Bay, CA
iTrader: (0)
Garage List 2018 Ducati Panigal ... [0.00]
2016 Mazda CX5 [0.00] 2017 Aprilia Tuono ... [0.00] 2019 BMW M2 Competi ... [0.00] 2015 BMW M5 Competi ... [10.00] 2016 Ducati XDiavel S [0.00] 2016 AMG GT S [0.00] 2011 Ferrari 458 It ... [0.00] 2017 Charger Hellcat [0.00] 2015 KTM Super Duke ... [0.00] 2016 KTM RC390 [0.00] |
Quote:
It's obvious that factory DME logic great for low output levels where knock isn't an issue. Where achieving the rated 300-340 horsepower (through various combinations of boost/fuel/timing) is the primary goal regardless of temp, humidity, baro, fuel quality, etc,. This dynamic behavior is courtesy of the DME's internal combustion model that those Germans sent a lot of time/resources developing. And it works as well (or better) than anyone could expect it to work. The problem, as we have all discovered by now, is that this goal is contradictory to what what most of us want in a tuned car. The idea of tuning is make as much safe power as the conditions allow. Not to attempt to make what is too much power when conditions take a turn for the worse and too little when conditions get favorable. Shiv |
|
Appreciate
0
|
01-17-2011, 01:56 PM | #100 | |
Brigadier General
102
Rep 3,460
Posts |
Quote:
|
|
Appreciate
0
|
01-17-2011, 01:57 PM | #101 | |
Brigadier General
102
Rep 3,460
Posts |
Quote:
|
|
Appreciate
0
|
01-17-2011, 01:58 PM | #102 |
Brigadier General
102
Rep 3,460
Posts |
BULLSHTI, should i quote all the times terry said "map up" to people in cold weather or on meth. Try again.
|
Appreciate
0
|
01-17-2011, 01:59 PM | #103 | |
Brigadier General
102
Rep 3,460
Posts |
Quote:
|
|
Appreciate
0
|
01-17-2011, 02:02 PM | #104 |
Mad Linux Guru On The Loose
1121
Rep 5,396
Posts
Drives: 2008 335i Sedan, 2023 M3
Join Date: Aug 2009
Location: Chicago, IL
|
HAhahah! So who is spreading misinformation here again????
__________________
6MT | COBB | AR | AE | Forge DV | HPF | P3 Gauge | Hybrid Intake | O.S.Giken TCD | All M3 bits | TCKLine | StopTech | UUC | ER | SPEC
|
Appreciate
0
|
01-17-2011, 02:15 PM | #106 |
1737
Rep 17,960
Posts
Drives: A Lot
Join Date: Sep 2006
Location: SF Bay, CA
iTrader: (0)
Garage List 2018 Ducati Panigal ... [0.00]
2016 Mazda CX5 [0.00] 2017 Aprilia Tuono ... [0.00] 2019 BMW M2 Competi ... [0.00] 2015 BMW M5 Competi ... [10.00] 2016 Ducati XDiavel S [0.00] 2016 AMG GT S [0.00] 2011 Ferrari 458 It ... [0.00] 2017 Charger Hellcat [0.00] 2015 KTM Super Duke ... [0.00] 2016 KTM RC390 [0.00] |
Come on man. I've looked at can dme boost target at varying levels of knock activity. And no appreciable drop in target. The big drop in boost comes in the form of a limp mode caused by glow ignition/knock codes.
|
Appreciate
0
|
01-17-2011, 02:23 PM | #107 | |
Brigadier General
102
Rep 3,460
Posts |
Quote:
Found it: The factory targets roughly 135; from the factory, the actual "requested" value can get knocked down when the ECU feels it is necessary It's entirely possible that if knock is induced over a long enough period that the ECU will change it's control/response strategy from "reduce timing in the noisy cylinders" to "reduce load requested to reduce cylinder pressures". Regards, Lance |
|
Appreciate
0
|
01-17-2011, 02:33 PM | #108 |
Cobb Stage 2+/ICarbon/HPF/Stett
40
Rep 488
Posts |
Hope things stay civil..
Shiv - I would simply like the issue of only monitoring cylinder 1 on the PROcede unit vs all and if that is the best approach for monitoring knock events and pulling timing. Thank you |
Appreciate
0
|
01-17-2011, 02:37 PM | #109 | |
Colonel
97
Rep 2,002
Posts |
Quote:
I'm interested to hear about this too
__________________
ESS 650 ACM-R Upgrades |
|
Appreciate
0
|
01-17-2011, 02:39 PM | #110 |
Second Lieutenant
6
Rep 291
Posts |
The DME sees knock with no piggyback interference. If it was going to lower it's boost setpoint you would see it.
Cobb saying "It's entirely possible" that the DME shifts strategy doesn't mean it does. All evidence points to it pulling timing until it gets to the point it goes into limp mode and cuts all boost.
__________________
2009 Spacegrau 335i |
Appreciate
0
|
Bookmarks |
|
|