Join Date: Jul 2007
Location: Harrisburg , PA, USA
Re: All you 87 octaners out there!!
Mine says 95 RON on the gas flap.
That is what I run.
For all the sophistication of this bike it really is only following basic timing and fuel curves based on the O2 sensor and the 14.7 stoich setting as was stated in the above posts.
I was not sure on a knock sensor on the LT? So this bike will not pull timing?
One of the reasons I decided to leave the first bike I ever owned in all my years, stock.
If I could get to the fuel maps then I would make this pig run. Power Commander offers for other BMW but not the LT. I would go with a Black Hole kit. The exhaust, fuel rail with bigger injectors, adjustable fuel pump, and Rhine West cams/Gears not sure which are offered, or both.
With no way to mind bump the fuel maps, you are too much at risk of running lean and cooking it, and while rich is bad, at current fuel prices it would just be insane. You also would need a good tuner and dyno to dial it in even with a Power Commander as it has no logging features for you to ride and adjust as needed.
There are very sophisticated EFI tunning devices out there. I am familiar with Dayton Twin Techs TCFI. You replaced your ECU with theirs, installed exhaust bungs for 02 sensors, adjusted IAC voltage, TPS fell in line, and ran it. No matter what cams, exhaust, heads, combustion chamber size, valve size, compression, whatever it will self tune, and will produce a log file of 30 minuets. So when you plug your laptop in you start the bike and can watch all aspects in live time in a Dyno Tune type screen, download the log file and see exactly where you are running fuel wise at what rpm, TPS, and what the timing was.You could change every fuel cell in every RPM?TPS range you wanted. Using that you can build your own timing curve. It was involved but with the radical Woods cams I was running it was the way to have a smooth running high compression, high overlap cam Harley.
The thing that amazed me on all of it was I would have to be set to 10.5 AFR at idle/low TPS for my logs to read 13.5 or so. So just because a AFR range is set to something, don't mean that is what it is running at. And if you don't see true AFR you will never know with out a knock sensor or something pulling the timing.
17.5 R1200 GSW Black Low
15 R1200 RTLC San Marino Blue Metallic (Sold)
10 Liquid Silver FJR1300 (Sold)
O7 Biarritz Blue Metallic LT (Totaled 2010)
ATGATT I am breathing proof.
BMW MOA #135959