04-24-2015, 08:26 AM | #1 |
Private First Class
30
Rep 131
Posts |
X5M Coldstart RPM - Tunable?
I currently have a Eurocharged tune on the truck and asked if they could lower the coldstart RPM to ~1000 instead of the 1500 it is at now, but they weren't sure if these tables were tunable. So I'm asking the community if they know if these tables are accessible and can be modified. My neighbors would appreciate this when I start my truck in the morning
|
04-24-2015, 11:47 AM | #3 |
Captain
107
Rep 994
Posts |
All cars, I mean ALL cars I've ever owned in 20 yrs, have cold start processes that raise the RPM's.
Because the car is cooler or perhaps in a colder climate, the higher RPM is needed to keep the car running. Don't dismiss a hundred years of combustion engine technology for your neighbor. |
Appreciate
0
|
04-24-2015, 12:33 PM | #4 | |
Major
603
Rep 1,206
Posts |
Quote:
__________________
I didn't know I couldn't do that. But I did know I couldn't do that.
|
|
Appreciate
0
|
04-24-2015, 12:37 PM | #5 | |
Captain
107
Rep 994
Posts |
Quote:
There are other things in play that address the catalytic. advanced timing, exhaust recirculation, increased fuel injection duration. raised RPM is for much more than the catalytic. Seriously, if you drop the RPM, the car would probably stumble and stall.
__________________
2012 X5 xDrive35i Sport Activity - Alpine White - M Sport Package
|
|
Appreciate
0
|
04-24-2015, 01:25 PM | #6 | ||
Private First Class
30
Rep 131
Posts |
Quote:
Eurocharged got back to me and will have an X5M in the shop in the next 10-days and is going to find the correct table. Quote:
|
||
Appreciate
0
|
04-24-2015, 01:47 PM | #7 |
Captain
107
Rep 994
Posts |
I'm not saying you can't. But it's not as simple as dropping the RPM.
Ever play with a carburetor? Ever had a carbureted engine? Remember that choke switch? Same concept. Basically, raising the RPM is one of the better ways dealing with the unburnt and poorly atomized fuel at startup. At startup the car runs richer too, to heat up the catalytics faster, etc. So simply lowering the RPM is not the right approach. Actually addressing fueling, among other tables will be needed. |
Appreciate
0
|
04-24-2015, 02:05 PM | #8 | |
Private First Class
30
Rep 131
Posts |
Quote:
|
|
Appreciate
0
|
04-24-2015, 07:59 PM | #9 |
Private First Class
6
Rep 129
Posts |
|
Appreciate
0
|
04-24-2015, 08:13 PM | #10 |
Private First Class
30
Rep 131
Posts |
What cars are your referring to? Cats have been around since the mid 70's and fuel injection started rolling out in the 80's. Before then it was carb based and didn't require an ECU to control functions like cold start. You had a throttle set screw for setting RPM. With electronic fuel injection and ECUs to control things like throttle position/idle control valves you also had the ability to modify cold start.
|
Appreciate
0
|
04-24-2015, 08:30 PM | #11 |
Private First Class
6
Rep 129
Posts |
Almost any vehicle built before cats were used. When first started, they would have a fast idle before settling down to the normal idle speed. So, the cats cannot be the reason if fast idle existed prior to the introduction to cats.
|
Appreciate
0
|
Post Reply |
Bookmarks |
|
|