F650 GS Dyno Runs FAQ

compiled & edited by Kristian #562; Scott, ID #1244
Please read the Disclaimer before attempting any work in this FAQ.
Last Updated: 18 April 2006

• Dyno Run #1 - Stock Bike
• Dyno Run #2 - Beau #645
• Dyno Run #3 - Fuel Nanny + Staintune (Techlusion)
• Dyno Run #4 - Various S/W versions - Robert #1071
• Dyno Run #5 - Two Brothers Exhaust
• Dyno Run #6 - Adventure Pipe
• Dyno Run #7: Dakar with 15T Sprocket

Also see the following FAQs:

• GS Performance Mods Index
• Classic Performance Mods Index

Original Link provided by Robert #1071

http://home.t-online.de/home/bbpower/f650st1.htm

STD Horsepower (Stock Bike)
This is the Dyno Curve for a Stock Bike BMW got it just right I don't see any room for improvement with the Stock Bike setup 42 HP at the Rear Wheel + 6 HP Lost through the Clutch (Measured) + 3 HP Lost through the Primary Drive Clutch (Estimated) 51 HP at the Motor
Torque (Stock Bike)
The maximum SAE Corrected Torque of the 650ccm Motor is developed at 5.4 kg-m At around 5500 rpm it starts to run out of puff.

Comments on this run:

• The Stock Engine is obviously particularly limited by a "Tame" cam shaft. Attempts with a better exhaust system also resulted in no improvement.
• A better result from tuning can probably only really be achieved with different cams and larger valves to improve the gas change. A sport exhaust system is probably also desirable. I look forward to being able to prepare the first tuned machine.
• There is no simple plug-in EPROM in the Motronic. It is soldered, making a normal exchange only possible with a socket insert. I do not have the possibility to upgrade or modify the software over the service plug, as with the BMW service computer.

provided by Beau A #645

Dakar +Staintune +K&N +FuelNanny -O2Sensor
Here are the Dyno results from my 01 F650GS Dakar with these modifications: Staintune exhaust w/o baffle Airbox modification from Techlusion website K & N Airfilter Techlusion PowerBox (Fuel Nanny) BMW 7.0 software upgrade & injector 02 sensor has been disconnected also

The max horsepower and torque figures are at 6300 r.p.m.'s. There is a steady rise from both H.P. and torque from 3500 up to 6300. At present, one major area of concern was the constant stalling while approaching intersections stop signs etc. We tried to duplicate a stall on the Dyno but never did. What little time I got to spend on the bike this w/e, the improvements were significant. With the baffle installed, there was a 3 HP decline. I'll report back and please inform me if I need to go back to the drawing board on the Dyno.

Maximum Horsepower is 41.8
Maximum Torque is 39.7

My ace tuner is Brian Nallin and he builds dirt-track, and drag racing machines, (Rotax and H-D). I hope you will find this information useful and I am sure we will have more info in the near future.

You can reach Brian Nallin @
Phone (318) 631-6747
Fax (318) 631-9798
Web & e-mail www.nallinracing.com, nascar@shrevenet

Comments on this run:

• My standard (except for K&N filter to get shot of BMW job) Classic put out 41.8 on a Dyno when it only had 5000 miles on the clock. The test came free with a pair of boots I bought at a dealers sale day, BTW. Either the tuning is horribly wrong or the exhaust etc. has no real effect except on fuel consumption. I suspect its a bit of both. Andy Leeds UK #982
• Motorcycle Consumer News tested the 1997 F650ST in February 1997 on a Dyno Jet Dyno and got 42.2 HP at 6,500 rpm and 38 lb. ft. of torque at 5,000 rpm. Richard #230
• Hi Beau, if I understand it the right way you made the same modifications as described at http://www.techlusion.com/F650.htm isn't it? But you haven't got an increase of power. Besides I have always wondered if the brown curve is a fake as it is not ending at the rev limit. To change that rev limit is nearly not possible. Since one year I am experimenting with the remapping of the software and the only thing I can change is the ignition point. Robert #1071

From: http://www.techlusion.com/F650.htm

Before: 2001 F650GS w/Staintune Exhaust
After: 2001 F650GS w/Staintune Exhaust and:

• 83i PowerBox
• K&N (prototype) Filter,
• Air Snorkel Modification.

by Robert #1071

Interestingly all three curves - old European soft 5000, 5000 with more pre-ignition and the current 8000 - are identical.

Unfortunately the AFR (Air-Fuel-Ratio)-meter did not work on that day.

• On the other hand there is no doubt that the Version 5000 has the worst emissions. In real life Version 5000 is running best. The main reason is that the 5000 is running open loop beyond 2000 RPM.

• The later versions (I have 7000 and 8000) are running closed loop up to 4500 RPM. closed loop = the lambda sensor value is taken into account. So there is absolutely no surging and a better throttle response when using the 5000 as a. the mixture is richer and b. the relatively weak ECU (Electronic Control Unit) has not so much to do.
• Concerning the max velocity all versions are very similar. Interestingly with the 7000 (=9.3) my F650GS had the best top speed whereas the 7000 had the worst driving comfort (a lot of surging).
  In addition I have that 5000 with more pre-ignition (red curve). I think I can feel more torque in real life but I cannot prove it.
• The main difference to the original 5000 is the fuel consumption. When driving at full throttle there is no difference but at slow driving, e.g. city traffic, there is a decrease of about 20%.

submitted by Rodnock

Dyno Test results of F650GS Snorkel modification, K&N Filter, Adventure Pipe exhaust, and Techlusion TFI systems

Dyno test results of Snorkel (intake plenum) modifications, and separately the addition of a K&N air filter showed no change in Horse Power or Torque output of the BMW F650GS over baseline. Adding a Techlusion TFI (1031) or "fuel nanny" and adjusting the pots for various exhaust system modifications resulted in 1 HP increase over baseline. The AdventurePipe aftermarket exhaust system added 3-4 HP between 3k and 5k RPM over baseline. Torque was also increased. Adding a snorkel modification, K&N filter, or Techlusion to the F650GS with AdventurePipe installed gave the same results noted above. These dyno tests were performed in Denver at an altitude of 5,280 feet. Baseline was a stock F650GS. It is possible that the results will be different at sea level, especially the Techlusion system results since this device adds fuel to the mix (bikes already run more rich at higher altitudes).

These test results indicate the most effective "bolt-on" modification to increase F650GS Horse Power is an aftermarket exhaust system. But, these dyno test results do not tell the whole story. Many F650GS/DAKAR owners report a "seat of the pants" improvement from a snorkel modification or K&N filter. This is most likely the result of better throttle response from these modifications. Improved throttle response provides better "driveability," especially at lower speeds and off-road riding, and will provide more "snappy" power delivery. The Techlusion system eliminates the surging problem found on many F650GS/DAKAR bikes, and this again is improved "driveability." Driveability improvements can be significant and can be just as important to the rider as an increase in horse power.

Thanks to bmwmarathon

Only modifications to the bike are a DID X-Ring chain and a 15-toothed front sprocket. I'd be currious to see if anyone else has had their bike dynoed and what kind of numbers/ modifications that have been made.