| Author | Message | ||
     Rick_a |
I did my first Dyno pulls with my XB head S1 on the weekend. Pretty dissappointing. She runs well yet is in all reality in a very poor state of tune. I got 84hp and 75ft-lbs with the poorest looking A/F curve I've ever seen. A majority was off the scale rich. At the high end it went to about 10.5:1. The guys here couldn't believe it wasn't smokin' or fouling plugs. Amazingly the torque and HP curves couldn't look better. 60ft-lbs practically off idle and a totally flat curve until the midrange where it starting climbing and then drops off after 6100 RPM. I've got some work to do but am optimistic I'll get 'er right eventually. | ||
| Loki |
Rick, Did you use the stock flat tops under the heads? If so the compression is down to start. I say this as mine only pulled the low mid 80s on the dyno. Jetting was nearly dead on for that given day. More room to grow by putting in the XB12 pistons and thinner gaskets. Or having the heads cut for T-storm or even someones Hurricane pistons. Engine pulls smooth and clean all the way up. Riding impressions? I actually like how the motor feels at this point. It feels like it took a little of the cam out of play. I mean it just does not lug till somewhat under 2k rpm. | ||
| Bomber |
Rick -- make sure they got the A/F probe inserted right -- the tech at a local dealer couldn't do so on my Wileyco CF can, and the A/F readings indicated that the bike couldn't run -- I am told it's tough, on some cans, to "turn the corner" so to speak | ||
| Djkaplan |
Sounds like a good start to me! | ||
| Ingemar |
What Bomber said. The readings may have been off, either because it wasn't inserted right or because of a faulty O2 sensor. I mean, too rich will be noticed by hesitations, the bike would be surging and running rough. | ||
| Spiderman |
That's what mine ran before I tuned it in. After tuning, 92 HP with 536 cams I am running 95+ | ||
| Kahuna |
There is definitely something wrong Rick! My bike is an all stock S1W except for a Buell race-kit/Force intake and an HSR42. I did two runs, one shown below with a 25/160 jet combo. and another (i cant seems to find the sheet) at 91.6hp & 81ft-lb with a 30/165 jet combo.  | ||
| Spiderman |
That's one happy dyno! | ||
| Rick_a |
I know it's wrong. The ignition isn't tuned, the jetting is way off, and I believe the exhaust is holding it back some. I know she was "probed" properly. I've done it many a time. Anyway, it's a 10.5:1 CR and Andrews N9 cam. I'll get it right eventually. I only get an hour of free dyno time a week. | ||
| Koz5150 |
I only get an hour of free dyno time a week. Lucky bastard! | ||
| Rick_a |
No way, it's only enough time to get set up and make a few runs. I have to wait another week to see the results of any changes. My new combination is so tolerant of tuning changes that it's hard to tell seat of the pants if I'm going in the right direction. Before if I was one needle position off or one jet size off I knew it. It's very frustrating. My brother told me it might have been that I was just so used to the way it ran before. Even crappy as it is, it does smooth wheelies and spins the tire really easily leaving from a stop. I also had my bud's Honda Hawk 650 on it before mine so I know the "sniffer" was working properly. His Hawk with cams and a full system made about 52HP and around 30 ft-lbs of torque. It weighs about as much as a small dual sport bike so it's still a pretty entertaining bike to ride. |
