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Old 05-19-2010, 07:34 AM   #48
Maddaddy's Avatar
Joined: Oct 2006
Location: Olympia, WA
Oddometer: 1,762

I will bring this with me.

Good to know about the the throttle on throttle off. That's another this was hoping to solve. At least I know not to be surprised or disappointed.

I'm going into this with an open mind.

Originally Posted by JoelWisman
I have done this before, on my dealerships owners bike as a test.

Be advised. The BMS-K has exactly 13 slots for software uploads beyond the orignal, after this, your stuck with whatever you have unless you buy a new BMS-K.

Updating the firmware on the BMS-K requires one slot. A remap for low octane fuel is an update to the latest firmware and will require one slot. Switching from the latest low octane map to the latest normal octane map will require one slot.

I can't see BMW ever releasing more then half a dozzen updates, but each update you choose to get will take a slot and each toggling between low and normal octane maps will take a slot.

I long ago switched to the latest firmware normal octane map and it helped quite a bit with snatchyness. Neither the latest normal octane map nor low octane map will help with the on throttle to off throttle engine breaking, but both of the latest normal and low octane maps retard timing for half a second when going from no throttle to light throttle. This does help.

Dave (owners) bike felt very snatchy when I first rode it, here are the steps I took and my impressions.

1: Adjusted throttle cable from BMW specked slack to as tight as I could get it without the idle raising when bars were turned from lock to lock. WARNED Dave that if the weather got cold without readjustment of slack, idle might raise at full lock, made sure Dave knew how to test for this and readjust throttle cable slack.

This helped quite a bit. I'm going to say this made 50% of improvement I precieved.

2: loaded latest normal octane BMS-K firmware. If your firmware is older (smaller number) then 7729155, then your firmware was previous to the ignition retarding snatchy mod.

Test rode. The latest normal firmware made the other 50% improvement in snatchyness I precieved.

3: loaded the latest low octane map 7729157.

I didn't percieve any snatchyness improvement from this mod over the latest normal octane map. For that matter, I barely precieved any hp difference at all. The only affect it seemed to have was a very slight reduction of hp above 7,000 rpm at full throttle and a slight reduction of responciveness when you quickly go from low or no throttle to full throttle at lower rpms.

This squares with BMW's stated figure that the low octane map reduces peak output by 4 hp.

In any case, Dave is happy with what I did. He was going to trade his 800 for a 650, and now he is going to keep the 8.

Then again, Dave owns a dealership and trades bikes all the time so take this with a grain of salt. :)

this is all inconclusive. I didn't ride his bike offroad, or on road enough, to form a firm opinnion of what all the low octane mod does, but whatever it does is suttle.

Loading firmware 7729155, if your firmware was older then this makes a BIG difference, and reducing throttle cable slack helps as well.

If you decide to update your firmware to the latest, or to the latest low octane map, it takes about 30 minutes as long as the GT1 does not crash.

If you decide to go fourth with the low octane map, do your dealer a favor and tell them where it is if they have never done it. It took me a long time to find the bloody low octane mod.

The keystrokes on the GT1 are: (Toolbox), (CIP), (F series), (F800,650), (Check sw), (Retrofit), (Fuel type).

Then the usuall 15 yes and ok buttons and key on and offs required to do anything on the GT1 lol.

P.S. I run 89 ron all the time and have never had detonation issues, for that matter, I've never heard detonation when i've been forced to run 87 ron. All with the normal map.
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