SJBMW Dual-Plug Conversion

Bottom line: after 200 miles of fast stuff this afternoon/evening, I've decided that the SJBMW 2-spark conversion is the Real Deal (tm). Seriously. Throw away the techlusion, bbpower chip, CCP, pipe, 02 sensor nonsense. This fix is the real fix. Surging...mostly gone. Power curve flatspots...mostly gone. Power increase due to using the LPB...yeah...very noticeable throughout the range. I meant to check mileage, but I was so focused on SNPA, that I forgot to fill up the tank. However, it looks like it's going to be good. I got 200 miles on the tank, and it dropped to two bars as I pulled into the driveway. That means I have at least another 60 miles left in the tank. Not a bad range...260 miles. I'll fill up tomorrow, probably, and post the mileage from this short trip. I think it'll be in the 40's, which would be higher than I've ever gotten. Pretty amazing since most of my ride was 80mph+ with massive headwind going up I-5 through the San Joaquin Valley.

It's effortless to cruise at 80mph+...90 if you have the nerve. I didn't use the Throttlemeister once, which is kinda interesting. No surge at stops or through towns. Power from deep down in the basement. I took off from a stoplight in second gear and the bike didn't complain. Before this change, it would ping, knock, complain, and maybe stall unless I revved it. Now it pulls from 2K up in all gears. Useable torque. It even accelerates in 6th gear (whoa) and pulls like a demon in 5th. I didn't do any high speed runs, cuz there just wasn't anyplace that was open enough to do it. I'd like to see if it will approach redline in 6th now...wouldn't that be cool?

I think this is the single most important and effective upgrade possible for the R1150RT, aside from a good windscreen.














More beer needed. SJBMW Rocks. Thanks again, Chris. This thing just flat works.

fish said:

Bottom line: after 200 miles of fast stuff this afternoon/evening, I've decided that the SJBMW 2-spark conversion is the Real Deal (tm).

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I see a couple pair of those coming to our house when we have some money again.

Thinking out loud here...
In the picture of the bare combustion chamber it looks like quite a bit of material is removed. I know most of it will be filled by the spark plug but not all of it. Do they weld up any other part of the head to compensate for the removed material. To me it would seem as though you would lose a point, maybe two of compression

Greg

Greg said:

Thinking out loud here...
In the picture of the bare combustion chamber it looks like quite a bit of material is removed. I know most of it will be filled by the spark plug but not all of it. Do they weld up any other part of the head to compensate for the removed material. To me it would seem as though you would lose a point, maybe two of compression

Greg

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I think it depends on how much reach the spark plug has. It may occupy enough volume to make up for the chamfer on the plug location.

Fish , Remember me Chris aka Titan.
Congratulation for excellent forum side you develop for MOA members.

I think you make good decisiom with your RT,
but I have same question like Greg;

looks like quite a bit of material is removed. What is done to compensate for the removed material.

Chris said:

Fish , Remember me Chris aka Titan.
Congratulation for excellent forum side you develop for MOA members.

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Yes, of course. How are you?

I think you make good decisiom with your RT, but I have same question like Greg;

looks like quite a bit of material is removed. What is done to compensate for the removed material.

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My gut tells me that with the sparkplug installed, there's not much difference. But you have me curious, so I'll check it out for you. It may be a moot point, because I think the small (if even measureable) difference in compression is a tiny price to pay for the tremendous improvement in driveability (rideability?).

One more question Fish

Sparkplugs,what San Jose recommend now for this set up.?

dual plugster

Nice write-up and pics. Tnx.

What is the price tag on this conversion?

Also, is this available everywhere or only at one dealer?

Mark

Chris said:

One more question Fish

Sparkplugs,what San Jose recommend now for this set up.?

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NGK BKR 7 EKC 0.8mm gap. stock. just four of them, instead of two

Re: dual plugster

oilhed said:

What is the price tag on this conversion?

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It's about $1000, including labor, using your heads. If you want to purchase heads with the machining done, I'm sure it would be considerably more expensive.

Also, is this available everywhere or only at one dealer?

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The dual plug conversion was developed at San Jose BMW, and they are currently the only ones providing this service. They may work with your local dealer, but you'd have to get the details from sjbmw.com.

For the record, I have no interest in San Jose BMW, just a satisfied customer.

so what about all the other stuff?

like the bbp chip, etc. did you have those installed prior and they are now gone or left in? thanks fro teh write up.

repoe3

Re: so what about all the other stuff?

repoe3 said:

like the bbp chip, etc. did you have those installed prior and they are now gone or left in? thanks fro teh write up.

repoe3

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The only other engine-related mod I have is a Remus Ti street system.

dual plug conversion

I have been intirged with this conversion since I heard BMW was
updating all oilheads with this modification.

However, I have an 1100RT, I'm wondering if this will work for me.

My R1100RT works Just fine in between annual tune-ups. But
more power is always a good thing. If there's a potenial for increase fuel efficency, that's good too.

So anyone out there had this done to an R1100R/RT/RS?
Beemmerboy

upgrade an r1100rt

Is there any way to upgrade a 2000 r1100rt so it uses the 2 spark plug cynlider heads???

I know this sounds strange but hey, you never know?

stephen

It's the same upgrade for the 1100. Contact sjbmw.com for details.

surging

For the people that can't spare the cash for the 2 spark up grades try indexing your sparkplugs. Use a single electrode sparkplug with lubricated threads and tighten so the open portion of the sparkplug faces toward the intake or one of the intake valves. tighten to 8 to 12 lbft. torque. indexing washers from Moroso can be purchased thru most high performance after market auto stores. reset your Motronic and five it a try it does help and is an inexpensive help.

Re: surging

Jeff said:

For the people that can't spare the cash for the 2 spark up grades try indexing your sparkplugs. Use a single electrode sparkplug with lubricated threads and tighten so the open portion of the sparkplug faces toward the intake or one of the intake valves. tighten to 8 to 12 lbft. torque. indexing washers from Moroso can be purchased thru most high performance after market auto stores. reset your Motronic and five it a try it does help and is an inexpensive help.

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Take a look here for some information about how the FI system is mapped. The problem is that the bike is absurdely lean below 40% throttle.

The legend on the side can be read this way: m = miss, sm = small miss DETONATION means lots of detonation and detonation means some detonation.

In addition to the lean condition, the timing is too adanced for some throttle conditions.

I'd guess that the miss is caused by there simply not being enough fuel available to promote consistent combustion. Running two plugs provides twice the ignition source.

http://vma.cape.com/~patrick/temp/bmw_r1100rs.txt

lean running

running 2 sparkplugs will speed up the flame thus advancing your timing, that the engine is running lean is accepted, indexing the plugs and aiming at the intake valves helps with getting the fire started in the combustion chamber more reliably. This is a very inexpensive help that keeps all engine systems active.