power. piston

[AndyW]

I know this is an old thread but this seemed as good a place as any to add this....

2007 R1200GSA with 125 BHP at the rear wheel (yes wheel not crank)!
Done by a Belgiun guy whose English is not up to him giving much detail (no criticism....I speak no Belgiun/Dutch!)

K&N Air Filter
Full Remus exhaust stystem
Cams - from BBPower
Pistons (higher compression) - from Wosner (machined the valve seat out of the pistons) they are higher on top for more compression
Injectors from RSR
and the fuelpresure is higger 4.2 bar.
"Chip Tuning" (which means TFI/Power Controller or PCIII?)

Photo story HERE

 

[Pukmeister]

AndyW, that's a tidy bit of work in that photo story, your mate Onze must be a good rider too.

I'd love to see that tuned GS on the road versus a stock bike.

 

[karlp]

Depending on what you want to achieve will influence your decision.

Cams can produce mid range power or high end power and depends upon the cam profile (duration of opening and valve lift).
When you change the profile of the cam you may possibley also change the time when the cam will open (this is why you need the adjustable sprockets).

However by using the adjustable sprockets you can only set one parameter - the inlet cam opening or the exhaust cam closing). You cannot set both as it is single cam. So unless the cams are engineered correctly it may become an impossible task to get both inlet and exhaust timings correct.

If you do not know anything about this then I would not use adjustable sprockets.

It is possible to get the valve opening and closing values from a dealer (but in my experience most do not know what you are asking for and act dumb).

It is best to dyno at each stage just to make sure you are going in the right direction.

Also you cannot put absolute faith in the bike having a base bhp as stated by BMW etc.

The main thing is do not get hung up by absolute bhp numbers as most people seem to do.

I would rather have a high torque at 3000 - 4000 rpm than high bhp at 8000 rpm and nothing below.

The power commander should be the last thing fitted and then set up correctly.

 

[Wild Will]

You have to be careful with cam timing. I saw two R1200S machines that had been tweaked at the cam sprocket hit the valves with the piston crown, destroying the engines. These were in Moto ST races in Florida in '07. I still have the "re-configured" exhaust valve in my shop! Also, those sprocket bolts are "one use", so replace them every time they're removed.

 

[teamwimp]

you won't lose torque.

Big bore was a common thing in the 70s and 80s and increases torque as long as you don't increase the valve size. Combine that with a higher lift cam and I doubt youd see a difference