04-26-2016, 04:24 AM | #1 |
New Member
6
Rep 27
Posts |
"Limp-Mode" on track
Recently had the very frustrating issue of my car going into "Limp mode" during a track day. Is there any way this can be avoided? Car has JB and DP's with semi's on the rear, but I don't think this would be causing it? This literally happened after a few short laps of hard driving. Does anyone know exactly what causes the car to go into this mode? Is it engine temp.? Seemed like hard braking triggered it on at least some occasions.
Any info / advice would be greatly appreciated. Thanks guys. |
04-26-2016, 06:35 AM | #2 | |
Perennial PFC
338
Rep 1,275
Posts |
Quote:
|
|
Appreciate
0
|
04-26-2016, 06:39 AM | #3 | |
New Member
6
Rep 27
Posts |
Quote:
|
|
Appreciate
0
|
04-26-2016, 06:41 AM | #4 | |
Hide! My wife's coming!
814
Rep 2,816
Posts |
Quote:
__________________
*** SOLD *** 2013 BMW M5 | Space Grey | MSR Stage 3 Tune | Catless Downpipes | MSR Intake and Charge Pipes | MSR Exhaust (Prototype) | Vorsteiner Rear Diffuser | RW Carbon Front Lip | RW Carbon Trunk Spoiler| Vorsteiner VS-310 Forged Wheels | Escort 9500CI w/Laser Jammers
|
|
Appreciate
0
|
04-26-2016, 03:05 PM | #5 | |
Plenipotentiary
2614
Rep 3,046
Posts |
Quote:
What tire setup are you running specifically? (Type and size) What DSC mode was active? (MDM or off) What was the ambient condition? (Temp, elevation, humidity) |
|
Appreciate
0
|
04-28-2016, 02:05 AM | #6 | |
New Member
6
Rep 27
Posts |
Quote:
Was running in MDM mode. Do you think running with DSC off reduces the chances of going in to Limp Mode? Ambient temp. was around 28 degrees Celsius, elevation is approx. 1700m above sea level and humidity is on the normal / low range. What confuses me is that I ran exactly the same set up with same conditions around another longer / faster track and had no issues. But around this other specific track (which is much tighter) the M5 seemed to hate it, going in to Limp mode as explained. |
|
Appreciate
0
|
04-28-2016, 07:21 AM | #9 |
New Member
6
Rep 27
Posts |
Spark plugs? Surely if that was the cause I would be experiencing it going into limp mode regularly, even after the track during road driving? The limp mode issue I had on the track was temporary, with the car returning to normal after a few minutes. I've never had the issue after that, and it has been a few months past.
|
Appreciate
0
|
04-28-2016, 09:09 AM | #10 | |
Colonel
354
Rep 2,176
Posts |
Quote:
|
|
Appreciate
2
|
04-28-2016, 11:15 AM | #11 | |
Plenipotentiary
2614
Rep 3,046
Posts |
Quote:
|
|
Appreciate
0
|
04-29-2016, 03:11 AM | #12 | |
New Member
6
Rep 27
Posts |
Quote:
|
|
Appreciate
0
|
04-29-2016, 04:04 AM | #13 |
Curve Thrasher
624
Rep 3,773
Posts |
When I had my bms I ran at Texas world speedway. I had no such issues w limp mode during or after. But after approx after 30k miles of use it did mess w my coils. Replaced plugs, coils and removed the bms for a tune
|
Appreciate
0
|
04-29-2016, 04:10 AM | #14 |
New Member
6
Rep 27
Posts |
What boost setting were you running with your BMS during that track day?
|
Appreciate
0
|
04-29-2016, 06:51 AM | #15 |
Curve Thrasher
624
Rep 3,773
Posts |
I used 3.0 for everything. I had no issues using it after adaptation. But a proper tune is so much better performance and the correct method for our cars
|
Appreciate
1
|
04-29-2016, 02:15 PM | #16 | |
Plenipotentiary
2614
Rep 3,046
Posts |
Quote:
Octane can become a factor (when the boost pressure available can no longer provide Atmospheric Sea Level at the intake Manifold, let alone over 1bar), higher octane fouls plugs quite easily as there isn't enough oxygen to facilitate complete combustion (so yes to the OP check the plugs as well, especially if you have a recent build with the Delphi Coils and CVO injectors Combo). Forced Induction, Direct Injection, Dual VANOS with a very wide adjustment range, and Valvetronic do help, but they don't make the engine immune to high altitude "sickness". The difference between Turbo-Charged and Turbo-Normalized comes into play, but is way outside my engineering skills. Some more recent S63TU (along with S55 and N63TU2) have a better ability to cope since they have different DME, Fuel Delivery System, inward vs outward metering valves on the injectors, updated coil packs (with unique cylinder heads), and revised wastegates. I lived part of the year for over a decade in an area where the main city (office) was 7800' ASL, but the suburbs where home was located is 8900' - 9400' ASL. Ambient temps were 19c-21c year round. Even lightly armored cars are heavy, so combining that penalty with the elevation and extremely steep roads, a bit more oomph is certainly wanted. I tried piggybacks but only two were ok if not pushed too hard (in-law's 1M Coupe and our X1 30i/N54 - strange local market version I haven't seen anywhere else). N63B40, N63B44TU, S63, S63TU were never happy. There aren't many major metropolitan cities at very high altitudes, and the subset with high ambient temps is vastly smaller at that. Turbocharged Gasoline vehicles are, surprisingly, not very common either. Usually larger displacement N/A variants with shorter final drive ratios and Turbo-Diesel are the most prevalent. |
|
Appreciate
0
|
Post Reply |
Bookmarks |
|
|