Scott's 2001 VFR 800, No frills and pretty much stock


Beth's 98 VFR 800, OEM blue bodywork and stripped rims

Installation of Power Commander II on the 98 VFR 800

The Purchase

  While reading one of the many VFR mailing list digests that I receive daily, I spotted a message about a clearance sale on Power Commander II's. I had been toying with the idea of getting one for the 98 VFR. After the install of the K&N air filter and the full Two Brothers stainless steel headers and C5 Titanium oval cannister, I knew the bike was running lean. Those two modifications made a noticeable increase in power based on my built in butt-o-meter. I just never got around to putting the bike on a dyno to verify my glutomatic readings. It seems that K&N, a reseller of PC II's, was getting out of the business. They would ship a unit to my door for $145, the normal retail being nearly $300 for a unit. How could I go wrong with that? I placed my order that night.

The Install

  The PC II is pretty much a plug and play setup. Of course, using it to adjust the bike's fuel injection mapping is another story. If you don't have a dyno handy with the appropriate software and exhaust gas analyzer, you have to work by trial and error. A long process at best. So I waited to install my unit until I could take the bike to an official tuning center and have a custom map made for our specific bike.

  At the recommendation of a fellow VFR lister, I took our bike to a tuning center in Dallas, Sabin Performance, owned by Jim Sabin. I arrived Saturday morning and we got started. Jim installed the PC II in a matter of seconds, like I said, "plug and play". But then it took him a while to figure out which wire was the RPM signal wire to the bike's computer brain. Once that was done, it was time for a baseline run to see what the bike is doing before we start. He loaded a zero map, one with no adjustments, and made a dyno run.

  Right off the bat I am pleased. With just the addition of the K&N air filter and the TBR full system, it appears that I have gained about 5 HP over the stock system. Stock, the bike should be making about 95 HP max and 54 fl-lbs max. The baseline shows a max HP of about 100 and a max torque of 53.25 fl-lbs.

The Tuning

  My unit came with the map editing software and a serial cable for interfacing the unit with a computer. Editing a map simply consists of tweaking the air-fuel ratio for throttle settings of 10% to 100% at varying RPM's. This results in a row-column matrix. In each matrix position, you can increase or decrease the fuel air mixture for that RPM-Throttle setting combination. Doing this in your garage can take forever if you have no way of determining what kind of ratio the bike has at its' present settings. This is the benefit of the real time readings a shop can provide.

  Jim uses DynoJet's WinPEP software in conjuction with the real time gas analyzer to monitor the fuel air ratio. He sets the test RPM to 1500 and then goes through the throttle settings from 10% to 100%. The dyno steadily increases the load on the rear wheel at each step. Thus to maintain the desired RPM, more throttle is needed. In this way each throttle setting is measured and adjusted for each RPM range. But that means there are 10 points of adjustment for each RPM setting, and there are 16 RPM settings. That makes for 160 adjustments!! Fortunately, Jim has experience at this and is good at getting right in the ball park in a hurry. It still takes a almost three hours to get it done.

  Other than the small delay when trying to find the RPM signal wire, most of the tuning went smooth and hitch free. However, at the higher RPM's, when Jim went even a little off throttle, the bike would start bucking wildly and the engine would lean out off the scale. He played with it a bit, and then finally decided that maybe I actually had a defective PCII unit. He offered to call DynoJet and speak with them for me. But then he had a thought to check the ignition advance table. At 100% throttle, there was 4 degrees of advance. He told me that those numbers had never affected any of the other bikes he'd ever tuned. But just in case, he zeroed them out and we tried again. The bike ran perfect.

  Tuning for the lower RPM's was interesting but not exactly exciting. However, once we started getting into the higher RPM's, say 8K and up, things got fun. It is hard to describe the spine tingling affect of listening to and standing next to a VFR at full tilt boogie under max throttle. The howl of the engine can be felt through your whole body. The air in the little dyno room is vibrating under the strain. The concrete slab shakes under my feet. The magnetic fields from the bike's ignition coils wreaks havoc on the computer monitor a few feet from the bike. The screen squirms and writhes as the fields pulsate over it. What fun!

  A group of Honda VTX owners had gathered out behind the shop. They were waiting for us to finish so they could have a dyno contest to see who is cranking out the biggest torque numbers. Stock, they make almost double the max torque of the VFR! Of course they almost weigh double ;-) When we were running the low RPM settings, most of them sat outside chatting and waiting patiently. As we started getting into the higher RPM's a few of them began to trickle into the dyno area to investigate the air splitting growl emanating from inside. "What kind of bike is that?" "That thing sounds incredible!" Like I said, nothing like it!

  Jim finished up and did a final run to verify the results. All of the runs are done in fourth gear. According to Jim, this is because fourth is more of a nuetral affect gear that gives a better indication of what the motor is actually doing. Lower gears make the motor look more powerful than it really is and higher gears make it look weaker. Also, for a fuel injected bike, running all the gears is not always necessary. However, for a bike with carbs, it is still done through all the gears. Below are the final results:

Air-Fuel Ratio /  Horsepower /  Torque

98 VFR Final HP and Torque /  01 VFR HP and Torque with K&N Filter only

  In all of the above images, run 001 is the baseline and run 007 is the final result with the custom map.


  I can't imagine wasting my time trying to get a meaningful map made for my bike by manually adjusting the settings, then going for a ride, trying to "feel" an improvement, retweaking, and so on and so on... It is worth it for me to take the bike to a shop and just have them do it right. Then I have a map that I know is good. If I still feel like tweaking, now I have a good starting point because I can use the custom map and go from there. Besides, it was fun!

  Once I got the bike home, I took it for a good ride. We rode two up on some of our favorite backroads. The throttle is smoother and does not feel quite as glitchy or choppy. The bike pulls hard and fast right up to the redline. The dip around 5000 RPM is still there according to the dyno results, but it is small enough that I don't feel it anymore. I have to do some extended riding to see if the gas mileage has been changed for better or worse. My initial reaction is that it has dropped. But that could also be because I have been ripping all over the place like a madman and whacking the throttle open to let the engine speak its' piece! I'll know better once my wife has ridden the bike more ;-)

  I spent a few hours messing with the bike trying to figure out how to permanently mount the PCII unit under the seat. Below are a few pictures of my solution. I simply drilled holes in the plastic wheel fender under the seat to match those on the unit. About 3/8" from those holes, I drilled another hole. Then I just looped a zip tie through the holes on each end and cinched it down nice and snug. I finished it off with some silcon goop to plug the holes and keep crud from the rear wheel from coming through the holes and making a mess. There really doesn't seem to be a good place to mount the connectors shown here above the tool kit. I just tied them off to the cross bar that supports the seat. The connectors don't interfere with the seat so they should be fine. Also, I have easy acess to the serial port on the back of the unit (red cap).

Pic One /  Pic Two /  Pic Three /  Pic Four

The Map

  I have had many people request that I share my custom map with them as they have an identical setup on their VFR's. Despite the fact that I paid $250 to have the map made, I am willing to let anyone that wants the map to download it for free.
There are a few things to note: The bike is a 98 VFR 800 with a full TwoBros header system and C5 Oval Titanium pipe, it has a K&N air filter, it had about 40,000 miles on it when the map was made, I have been running full synthetic oil in it from about 10,000 miles. Why does all this matter? Every bike is slightly different. The map is based on the real time air-fuel ratio of the our specific engine while under various loads. Part of those loads are internal to the engine and also the drive train, not just those from the dyno. How much a part, I really can't tell you. But just because you have a 98 VFR 800 with the same stuff as ours, does not mean this map will be optimum for your bike. That being said, it may still be better than the stock map, so give it a try if you like.

  As I said, you can have the map for free. However, you take it and decide to use it, please consider making a donation of any amount to help me recover the intial $250. I leave it to your discretion as to the amount, if any, that you want to donate. If you want to send a check, drop me an email and I'll give you my address, or you can just send it via Pay Pal

PCII Map for 98 VFR


  If you view the map you will see that the comments state that you should only run 93 octane and some nonsense about the ignition advance. IGNORE THIS. When the tuning was being done, Jim forgot to edit the comments to reflect that 87 octane and zero ingition advance is the setting. The bike was tuned with a tank full of 87, I have always run 87 and I still do. And like anything else, use at your own risk ;-)

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All contents are copyrighted materials of Scott Friday, 1998-2005.