| Author | Message | ||
     Sanchez |
I took my bike to Stone Mountain Harley-Davidson Monday for a dyno run only to find that my bike is too short for their CycleDyn dyno. Wtf? Anyway, my uncle and I headed out to the Tail of the Dragon yesterday, and we stopped at Wheeler's cycle shop for a run on the Dynojet. The results were less than steller: 73 rwhp and 66 rwtq. I'm wondering if perhaps the dyno is off, though. An 04 XB12 on the same dyno only made 83 rwhp with a race kit, ecm, etc. Shouldn't an XB with those mods be a little over 100? If the dyno's off, that puts my bike closer to 90, which is where I expected it to be. Anyway, here's the graph.  For comparison, here's my graph vs a stock X1 on the same dyno:  The M2 seems to have a distinct midrange advantage, while the X1 takes off above 5k rpms. | ||
| Cyclonecharlie |
Sanchez, When my M2 had what yours had(cams,race header,ecm & aircleaner)it pulled about 10 more(82 or 83 hp) so yea I think it might be alittle off. You can get alittle more with the 44 intake and more yet with 44 carb..............Charlie | ||
| Cyclonecharlie |
Sanchez, Did you get an A/F value with the dyno sheets? You maybe running to rich. | ||
| Firemanjim |
Not all dynos are created equally--nor are all operators! Might have been the opposite of a "happy" dyno.The one that was at Dave S's shop at Homecoming was giving similar results to everyone--lower than expected.Can't really tell from one run anyway. | ||
| Scott_in_nh |
Dyno's are best used as a before and after comparison on the same dyno. Performance gains (IMO) are best measured on the the dragstrip though it takes some skill. At least you know what the bikes did stock so it is easy to compare, it is real world (not all dyno gains show up as expected), and is a lot more fun! | ||
| Sanchez |
Charlie, no, I didn't get the A/F. I wish I'd thought of it at the time. My instinct is that it's running too lean, but I can't prove it. I still have the stock carb with factory jetting. Anyone know of a good tuner in the Atlanta area? I wasn't ever planning on having it dyno tuned, but I'm kind of considering it now. | ||
| Bomber |
last dyno run i got (at a dealership not to be named) -- the operator couldn't get the A/F sensor in properly, and it gave really wonky results -- your results aren't too far off what you could expect -- like the fireman sez, could just be a sad dyno . . . . . | ||
| Blake |
I disagree. Looks like a very bad/inaccurate dyno to me. An XB12 should be up around 90 SAE RWHP. | ||
| Sloppy |
Dyno's are NOT absolutes. Remember that Dyno's don't measure power, they calculate it. Tire slippage, operator, engine temperature, etc., are all variables to the calculation. Scott's on the money - use the Dyno to measure changes, but only on the same Dyno with the same operator. My 2000 S3 measures a consistent 85 RWHP after two years with the same dyno operator. | ||
| Cyclonecharlie |
Sanchez, The A/F values are more important than the hp readings. They determine your state of tune. You may find with the different cams that you may have to lean out your motor. Until your A/F value is right, your other numbers won't be......Charlie | ||
| Scott_in_nh |
What Charlie said is very correct! | ||
| Sanchez |
Anyone know of a good tuner in the Atlanta area? I know SMHD does dyno tuning, but of course my bike won't fit on their dyno. Also, will I need to drill out the bung in my header, or can they use a tailpipe sniffer? | ||
| Firemanjim |
All dynos I have seen use tailpipe sniffer. | ||
| Blake |
Actually Dynos like the Dynojet inertial types do come pretty close to actually measuring power. They continuously measure the time it takes for the drum to make one revolution. From that time interval data and knowing the mass properties of the drum, mass moment of inertia to be exact, along with frictional factors, the power is calculated. I agree that various factors will affect the results of a dyno run, but that one is way outside of the envelope for a Dynojet dynamometer reporting corrected results. | ||
| Chevyguy80 |
I have a 2000 x-1 with a force winder intake and the full race kit (header and muffler. Had it dynoed at 6900m. It layed down 75hp & 74tq at 5500 rpm with an a/f of 12.3:1 not to far off of yours. The only differnce is that the lines were beautifully smooth all the way. Hit 70 plus on both by 3300rpm and never dropped. The only reason we stopped at 5500 is the clutch started slipping. Was done by the most straight forward shop in the pheonix area | ||
| Cyclonecharlie |
Chevyguy, Most of the X1 I have seen with the race kit are pulling mid to high 80's. However none had a forcewinder and 12.3 seems alot rich to me. IMO mid 13's would be better. How many pulls did they do to get you those numbers?.......Charlie | ||
| Sanchez |
Looking at the X1 graph above, I suspect he'd have gotten at least another 10 hp if he'd run all the way to redline. | ||
| Chevyguy80 |
We pulled five runs on the dyno. The guy doing the runs said that around 12.7:1 to 13.0:1 would be ideal for a sporty. They havent really had a lot of experience with buells they are more of a chopper shop | ||
| Cyclonecharlie |
Chevyguy, If the bike runs good and your happy with it then your good to go. However at a A/F reading of 12.3, IMO you still have alot of power still on the table. Go to the KV vault and look at the dyno sheets for A/F values. What are you getting for gas mileage?....Charlie | ||
| Chevyguy80 |
I get between 40 and 45 depending on how hard Im beating on it. I just think the bike wants a shot of nos like a 50 shot just enough to put it barely over 13:1 | ||
| Cyclonecharlie |
Chevguy, Don't have any personal experience with NOs.,But a few years ago I knew a couple of guys that used it on the strip and they said it was a pain in the B. Not that it didn't work good, it did. But having to store the bottles in the refrig. and just general maintnance. The systems might be better now, don't know. I see alot(a half a doz.) bikes running around with a NOs sys.(no Buells)but when I press them for answers, there bottles are empty and some have never used it.(all for appearance) | ||
| Chevyguy80 |
got a alot of exp with it on cars and a few years back had a buddy with a 50 shot on an older 1100 ninja that was a fun bike other than that none but why not try it i live about 15 miles from MMI im sure some one over there can give some advice if needed the buell is my fun bike anyway got another one that i ride like everyday so if i kill it just gives me a reason to tear it down and make it bigger and bader | ||
| Diablobrian |
There are Buells with NOS on them around. Firemanjim has it on his LSR bike, as does No_Rice on his street bike. Iv'e played with it before myself on other bikes, and i really recommend a "wet" system if you do it. it adds it's own extra fuel when you push the button. This is much better than experimenting and possibly holing a piston by leaning it out the first run. I've seen that happen with "dry" systems | ||
| M1a65 |
Matt, My 00 M2 ran 75 RWHP with 76 of torque. I'm running a K&N in a gutted airbox with a Sporty venturie. 175/42 Thunder Slide kit jets on the CV with the Daytona Boss muffler. Wish the readings were higher too but the torque curve was flat from 2500rpm to redline. For where we ride I think that'll do just fine. I had it tuned at American Twin in Fayetteville by a guy who tunes drag Harleys. I feel he could have tweaked it a little more and gotten some more out of it (theres never too much power). He charged $90. Might take it back one of these days when I'd rather give my cash away than drink it at the V. all the BEST! |
