Here is the setup 2004 KFX 700 (purchased in Feb 2003) completely stock bike with fresh Mobil 1 oil and NGK plugs and a Dalton Orange – Blue clutch spring (stock weights, no O/D cover). Only external engine mods were performed for the testing, no clutch changes were made at all. This was on VForceJohn’s DynoJet Dyno in PA. All runs were done inside with temp ~ 65* and no setup changes were made to the dyno between runs. All runs after the Muzzy was installed were done with the Air/Fuel probe of the dyno inserted into the exhaust to allow for tuning A/F mixture through the carbs.
Here is the mod list (BTW, all mod parts are new):
Bartlett airbox mod (using Twin Air instead of K+N air filter)
Muzzy 2 into 1 exhaust
Dyna CDI
Before anyone says anything about CVT’s and dyno testing, my objective was to see a definitive power increase based on my mods and to be able to tune my A/F ratio properly. I understand that the numbers the dyno kicked out may not have been 100% accurate because of the CVT. However, there is no denying that with my baseline run and keeping all parameters the same throughout (except for adding mods), that the dyno can clearly show if a mod is making horsepower or not.
Dyno Runs 1-9 listed, second number is rear wheel horsepower (rwhp)
1 35.69 Stock bike (Stock bike with Dalton O/B spring)
2 36.52 Stock bike plus Dyna CDI only (gained 1hp and 1 lb/ft torque)
3 40.29 Muzzy, Twin Air, Stock CDI didn't count, A/F probe blew out
4 41.16 Muzzy, Twin Air, Stock CDI (B/C Jets from Bartlett kit)
5 41.45 Muzzy, Twin Air, Stock CDI (C/D Jets from Bartlett kit)
6 41.82 Muzzy, Twin Air, Stock CDI (Drilled main jets)
7 41.22 Muzzy, Twin Air, Dyna CDI (Drilled main jets larger)
8 41.43 Muzzy, Twin Air, Dyna CDI (Drilled main jets even larger)
9 41.52 Muzzy, Twin Air, Stock CDI (same jets as run 8)
The last 4 runs were made in pretty quick succession with no cool down time for the bike. They were all made within about 15-20 minutes. I suspect a cooler bike at the end would have probably netted me ~ 41.9 to 42 hp on my last run.
Lessons learned?
You should jet up at least one size when running the Dyna CDI and any airbox or exhaust mods. The Dyna CDI made my bike run leaner. On a stock bike, it put’s the Air/Fuel ratio much closer to where it should be to make power from the factory. Stock, the bike made 1 more hp and 1 more lb/ft of torque with the Dyna CDI and brought the A/F ratio up closer to the 12-13 range (instead of the 11-12 from the factory). Personally, I don’t think you will ever come close to using the extra rpm from the Dyna CDI over the stock rev limiter unless you go inside the motor and do some mods.
There are currently no jets available to make the bike rich enough with a Twin Air element (with Bartlett’s airbox mod) and Muzzy exhaust. My jets were drilled with a 3/16” bit to get them as close as possible. It is still a touch lean but not dangerously so.
This part is my opinion (because the dyno does not lie), but it seemed to me that even though the Dyna made less horsepower than the stock CDI, the bike went through the upper RPM’s faster with the Dyna CDI on than with the stock CDI. By the time it get’s to that point during the dyno run, the clutch shifting can really change the output. John explained to me the acceleration vs. time settings on the dyno while he was setting it up, but I didn’t even think to check and see if they were different during the runs with the Dyna CDI. That may have given us a clearer picture of what was happening in the upper RPM range with the Dyna. It may very well have been accelerating faster, but the clutch may have made it almost impossible to see. Even though it made less power, I am inclined to believe that the “sweet spot” for the Dyna may very well be in the upper RPM range by holding the timing longer than stock. I will only be able to test this with a seat of the pants run.
I will post a few pics of the dyno runs if anyone wants to see them. Along with some pics of my naked V-Force on VForceJohn’s Dyno.
I would love to hear everyone's feedback.
Thanks,
chris
Here is the mod list (BTW, all mod parts are new):
Bartlett airbox mod (using Twin Air instead of K+N air filter)
Muzzy 2 into 1 exhaust
Dyna CDI
Before anyone says anything about CVT’s and dyno testing, my objective was to see a definitive power increase based on my mods and to be able to tune my A/F ratio properly. I understand that the numbers the dyno kicked out may not have been 100% accurate because of the CVT. However, there is no denying that with my baseline run and keeping all parameters the same throughout (except for adding mods), that the dyno can clearly show if a mod is making horsepower or not.
Dyno Runs 1-9 listed, second number is rear wheel horsepower (rwhp)
1 35.69 Stock bike (Stock bike with Dalton O/B spring)
2 36.52 Stock bike plus Dyna CDI only (gained 1hp and 1 lb/ft torque)
3 40.29 Muzzy, Twin Air, Stock CDI didn't count, A/F probe blew out
4 41.16 Muzzy, Twin Air, Stock CDI (B/C Jets from Bartlett kit)
5 41.45 Muzzy, Twin Air, Stock CDI (C/D Jets from Bartlett kit)
6 41.82 Muzzy, Twin Air, Stock CDI (Drilled main jets)
7 41.22 Muzzy, Twin Air, Dyna CDI (Drilled main jets larger)
8 41.43 Muzzy, Twin Air, Dyna CDI (Drilled main jets even larger)
9 41.52 Muzzy, Twin Air, Stock CDI (same jets as run 8)
The last 4 runs were made in pretty quick succession with no cool down time for the bike. They were all made within about 15-20 minutes. I suspect a cooler bike at the end would have probably netted me ~ 41.9 to 42 hp on my last run.
Lessons learned?
You should jet up at least one size when running the Dyna CDI and any airbox or exhaust mods. The Dyna CDI made my bike run leaner. On a stock bike, it put’s the Air/Fuel ratio much closer to where it should be to make power from the factory. Stock, the bike made 1 more hp and 1 more lb/ft of torque with the Dyna CDI and brought the A/F ratio up closer to the 12-13 range (instead of the 11-12 from the factory). Personally, I don’t think you will ever come close to using the extra rpm from the Dyna CDI over the stock rev limiter unless you go inside the motor and do some mods.
There are currently no jets available to make the bike rich enough with a Twin Air element (with Bartlett’s airbox mod) and Muzzy exhaust. My jets were drilled with a 3/16” bit to get them as close as possible. It is still a touch lean but not dangerously so.
This part is my opinion (because the dyno does not lie), but it seemed to me that even though the Dyna made less horsepower than the stock CDI, the bike went through the upper RPM’s faster with the Dyna CDI on than with the stock CDI. By the time it get’s to that point during the dyno run, the clutch shifting can really change the output. John explained to me the acceleration vs. time settings on the dyno while he was setting it up, but I didn’t even think to check and see if they were different during the runs with the Dyna CDI. That may have given us a clearer picture of what was happening in the upper RPM range with the Dyna. It may very well have been accelerating faster, but the clutch may have made it almost impossible to see. Even though it made less power, I am inclined to believe that the “sweet spot” for the Dyna may very well be in the upper RPM range by holding the timing longer than stock. I will only be able to test this with a seat of the pants run.
I will post a few pics of the dyno runs if anyone wants to see them. Along with some pics of my naked V-Force on VForceJohn’s Dyno.
I would love to hear everyone's feedback.
Thanks,
chris
