Login






BMW Garage  BMW Meets  Register  Search  Today's Posts  Mark Forums Read 

BMW 3Series (E90 E92) Forum
>
Fueling Resistors  What Do They Do? Using This Data for Upgraded Turbos or Nitrous


05142010, 09:19 AM  #23  
Major General
169
Rep 5,179
Posts 
Quote:


Appreciate
0

05142010, 09:23 AM  #24 
Brigadier General
54
Rep 3,464
Posts 
When you request enough fuel you get a point where the fuel pump can't keep up with the request. So if it can't keep up and the injectors are spraying wide open, you drop pressure. If you see pressure drops, chances are you maxed out the fuel pump. In some di cars (not sure about this one) this results in a false rich condition as fuel is simply spraying past combustion.

Appreciate
0

05142010, 09:27 AM  #25  
Major General
169
Rep 5,179
Posts 
Quote:
Second, the fueling resistors are also limiting mid range fueling right now to 14.0:1 and in my opinion that is not good enough for aggressive setups. You need to bias the O2 sensors more than the ~5k ohm resistors allow. I know I don't feel good triggering nitrous on an AFR of 14.0:1 in peak torque. 

Appreciate
0

05142010, 09:39 AM  #26  
Brigadier General
54
Rep 3,464
Posts 
Quote:


Appreciate
0

05142010, 09:41 AM  #27  
Major General
169
Rep 5,179
Posts 
Quote:


Appreciate
0

05142010, 09:47 AM  #28  
Brigadier General
54
Rep 3,464
Posts 
Quote:
I would have to call cpe, but it would also make sense that these pump have a pressure release valve, meaning you can't go past a certain pressure which limits fuel as well. But this is just something im basing off previous platforms, not this one. Once you get into all this deeper you will quickly realize that your next car will be PI. I know mine will lol 

Appreciate
0

05142010, 09:53 AM  #29  
Major General
169
Rep 5,179
Posts 
Quote:


Appreciate
0

05142010, 09:56 AM  #30 
Brigadier General
54
Rep 3,464
Posts 
Certainly not a bad number to be at, but it makes you wonder why asr/shiv and cpe ams both hit fuel limits at around 460480 without meth. None of the details were explained the forums. What ran out? the pump, the lp pump, the injector duty cycle? You are right around that, so I would just be careful cause I am not sure what this car does when you exceed either of these fuel hardware limitations. Does the throttle close? Does timing get retarded? Does anything happen prior to knock?

Appreciate
0

05142010, 10:06 AM  #31  
Major General
169
Rep 5,179
Posts 
Quote:


Appreciate
0

05142010, 10:11 AM  #32 
Brigadier General
54
Rep 3,464
Posts 
So your 487 clutch slipping dyno, is maybe a little over 500 on dynojet, so you are close. Also asr was not requesting the a/f ratios you are, if they were, i havn't read about it. so your right there. I know personally ams at 450ish trying to make it run rich, over powered the fuel system. At first we thought i was another fp that ate shit. However it was their 5th fuel pump in a couple of months, so that couldn't be the problem. And it wasnt.

Appreciate
0

05142010, 10:36 AM  #33  
Major General
169
Rep 5,179
Posts 
Quote:
I am not sure what ASR requested on AFR because it was never made public. I cannot imagine how AMS overpowered the fuel system at 450 rwhp though. The runs I posted with the 2.2k versus 1.0k are running around 440 rwhp. Clearly the car is accepting the richer AFR demand without problem. 

Appreciate
0

05142010, 10:48 AM  #34  
Brigadier General
54
Rep 3,464
Posts 
Quote:


Appreciate
0

05142010, 10:52 AM  #35 
Major General
169
Rep 5,179
Posts 
Hmmm, that is interesting to note. It will be interesting to see then how my mid range reacts on the nitrous now. I will say that the midrange has hands down been the most stubborn to richen up. I can get huge changes in high rpm A/F, but the mid range has been very stubborn to change. What means were you guys using to monitor FP?

Appreciate
0

05142010, 11:11 AM  #36  
Brigadier General
54
Rep 3,464
Posts 
Quote:


Appreciate
0

05142010, 11:14 AM  #38 
Major General
169
Rep 5,179
Posts 

Appreciate
0

05142010, 11:16 AM  #39 
Major General
169
Rep 5,179
Posts 

Appreciate
0

05142010, 11:18 AM  #40 
Brigadier General
54
Rep 3,464
Posts 

Appreciate
0

05142010, 11:24 AM  #41 
Major General
169
Rep 5,179
Posts 

Appreciate
0

05142010, 11:30 AM  #42 
Brigadier General
54
Rep 3,464
Posts 
Not trying to do that, but when you're pushing the limits and don't even know wtf the numbers you are logging mean, it makes yo go hmmmm. Thats one of my problems with the jb3, everythign and its mother in that thing is an arbitrary number. Try setting 40, change column two to 10, and the 3rd setting to 65, do a datalog. lol wtf did I just change and by how much? Thats I simply just can't live with, but people are different.

Appreciate
0

05142010, 11:46 AM  #43 
BimmerPost Supporting Vendor
596
Rep 24,387
Posts
Drives: C6 Z06, GSXR750, 09 335i
Join Date: Dec 2008
Location: www.TopGearSolutions.com

Anyone can like a tuner all day cause hes a stand up guy and whatever else you like about them.... but what tune offers your car to run optimally.
Tune>tuner 
Appreciate
0

05142010, 11:53 AM  #44 
Major General
169
Rep 5,179
Posts 
JP, Terry has tuned me to the highest pump gas E92 in the world that we know of. I was a clutch away and MS109 from taking the ASR race gas / methanol record. I have the MS109 now, the Clutch Masters Twin Disk, and will attempt to take that record in my next dyno session. Honestly, I am not sure what else I could ask for? I have what I would consider a good knowledge of cars, but I am still not a tuner.

Appreciate
0

Bookmarks 
Thread Tools  Search this Thread 

