AF-XiED installed - Test ride and first impressions - '00 r1100s

Hi all,

I finally overcame my natural laziness and installed my new AF-XiED, which arrived a couple of months ago from Beemer Boneyard. I hadn't been in a big hurry to deal with the fuel tank and whatever else might be lurking up in there, but the other day it was pouring down rain and I couldn't stand the suspense any longer. I had bought the device with the hope that it would help smooth out the engine performance of this otherwise great machine, but I had been beating around the bush by doing everything else I could think of first.

The basics:
2000 r1100s, single spark, stock intake (w. K+N filter element), stock exhaust, 24,400 miles. I've owned it for five or six months.

Repairs and adjustments done by yours truly:
Valve adjustment, all fluids replaced, carb sync, new plugs, spline inspection (via starter port) - all results ok and up to spec, more or less. 2mm spline play, valves, rockers, chains all look good. Engine now much quieter and smoother. Carbs now in sync at all rpms.

Two problems remained: A sort of anemic idle, which I couldn't cure despite all the adjustments, and that durn surging, which was really irritating and which was certainly not helping the running gear. I pretty much had to stay above 4000 rpm in any gear to keep it smooth, which meant that I had a choice of either first or second gear here in town and could expect no more than 100 miles out of a tankful of premium fuel. Basically the bike was great on the highway but not much fun otherwise.

I'm happy to report that the AF-XiED made a huge difference in the performance, like night and day. It's still happier above 4000, but you can forget and slip down into the lower 3s and cruise for a while in traffic before you notice any surging, and it's noticeably smoother when it does happen. The idle feels much stronger, even though it's unchanged at 1000 rpm, and the off-idle response is much smoother and surer. I used to feel like I always had to keep the idle up at traffic lights and the bike was also fairly easy to stall, especially when the engine hadn't warmed up yet. That's over now.

I'm really pleased with the upgrade and consider it to be money and labor well spent indeed. I'm just going to leave it set on 7, the way I received it, for now, as it's running great and I get a solid green light all the time. It's not quite as smooth as my brand-new R69 was, but it's doin' all right. Suggestions, anyone?

Kudos to NightRider and to Beemer Boneyard for this great product.

Bonus feature: Love the little red and yellow and green lights!

Johnny

Back again with update -

I've run a tankful of fuel through my bike over several days, all in around-town riding, so I tried turning the AF up from 7 to 8. The manufacturer, NightRider, says that either 7 or 8 is normal for stock intake/exhaust bikes, so I thought I'd try 8 and see if I could tell any difference. (NightRider sends them out set at 7, so that must be what they consider the base setting.) So I'd say that yes, I can tell a little difference, a small but noticeable improvement, in smoothness off-idle and in cruising with minimal surging between 3 and 4 thousand rpms.As I said above, the difference between what I have now and what I had before I installed the device is truly amazing.

It does seem to have a little lumpier (is that even a word?) idle now, set at 8, so I'm thinking that the setting may be approaching the point of diminishing returns. The engine sounds great at idle, but it's, you know, lumpy. It idles at 950-1000, which is great for getting into first from neutral, but the clutch and trans make it sound like either a worn-out corn binder or a Ducati at that rpm, so I tend to sweeten it a little at the traffic lights. That's OK, I'm happy to make that trade. Plus people say "Dude, is that one of them Ducatis? And I say "No, it just sounds like one." So, pretty cool.

85-90 degrees F, 0 to 10 feet elevation, high humidity - 8 may be the correct setting.

I'll keep in touch,

Johnny

I run mine at 8 & the longer you run it you'll find it gets better. I can tool along at 50 mph in 6th. And generally at 2500 rpm in any gear but 6th.

Thanks for that, Kutter,

I think we may have hit the sweet spot here at 8. Plus I've heard from others as well that it keeps getting more acclimated to the setting as you put more fuel and miles on it, so my first ride should be a good predictor of future performance. I'm going on a 800 or so mile trip next week, so things are looking good.

Johnny

There have been numerous discussions about lugging the engine in 6th gear possibly adding to premature wear of the input shaft. But thats a whole new topic.

Yea, you still need to be careful with 6th gear. I found it will pull 6th around 3 grand fairly well but requiring a lot of torque I generally downshift to 5th. You certainly don't want to lug it in any gear & it still is easiest to lug it in 6th. What is nice is that where you used to need 3500 -4000 rpm to decently pull the next gear now that happens 1000 rpm lower and allows you to be riding at least a gear higher than before.

PAS said:

There have been numerous discussions about lugging the engine in 6th gear possibly adding to premature wear of the input shaft. But thats a whole new topic.

Click to expand...

There's no evidence that this happens and no reason to suspect it is a risk. Here's why:

1) the shaft torque in high gears at low RPMs is very low. For instance if you're riding in 5th gear with a transmission input shaft torque of 10 ft-lbs. and up shift to 6th, the input shaft torque is still a mere 13 ft-lbs.

2) if you are riding in 6th at 60 mph, 3000 rpm and rotate the throttle to WOT, the engine can only output 45-50 ft-lbs. of torque. If you are in 3rd/4th gear at 60 mph and 5000 rpm then crank the throttle to WOT you get nearly 70 ft-lbs. at the input shaft. Clearly cranking the throttle open in a lower gear is worse.

Below are some tests I made in higher gears.

roger 04 rt said:

Yesterday afternoon I wanted to put Jim's very-rich 12.9:1 to the test on the road. My goal was to find out the lowest RPM before I could make the engine actually "lug". I was amazed.

First off, the bike is fine at 1500-2000 rpm in 5th gear. Roll the throttle, no lugging. Make a left or right 90 degree turn in 4th gear, no sweat. Start in 2nd gear, not a problem, feels like 1st.

Cruise up a shallow incline in 6th gear with no throttle input at 18 mph, 900 rpm (rpm dropped below its usual 1100 at idle), no lugging. However, try and give it some throttle at that point, the engine is not happy--lug, lug, almost stall.

After a little trial and error, as long as the rpm was higher than 1200-1300 rpm, the bike would accelerate without lugging.

With enough fuel the '04 RT engine has real guts.
RB

Edit. In 6th gear, straight and level, it takes 0.7 HP to cruise at 18 mph. Engine torque at the transmission input is about 4 lb.-ft. So add a couple lb.-ft. for my shallow uphill trajectory.

Click to expand...

Hi Roger, I think the problem with your theory is you forget that in 6th gear there is much more load placed on the engine which is transmitted to the engine through the transmission input shaft splines. Try starting from a dead stop in 6th gear sometime.

Not forgotten. In 6th gear there is 30% more load on the transmission input shaft than for 5th gear, at the same speed. After rerunning the numbers, at 50 mph in 6th gear the transmission input shaft torque is 12 ft-lbs. and at the same speed in 5th it is 9 ft-lbs. That 3 ft-lb. difference isn't going to create significant differences in wear.

But because torque rises from 2500 to 6000 RPM, if you suddenly fully open the throttle, there is more torque place on the shaft in the lower gear. So the higher gearing from running in 6th limits the torque available from the engine by limiting the RPMs.

The most loading/wearing action on the transmission input shaft is WOT at high RPMs--more torque and more transmitted HP.

That 3 ft-lbs doesn't seem like much but that is still a 25% increase in load on splines that are not in full mesh because of what must be an engineering oversight at BMW. I don't know about you but I hardly ever whack open the throttle and never in upper gears. Oh, and then there are the twin cylinder power pulses at lower revs.

Sorry for this hijack, I'll shut up.