| Author | Message | ||
     Matchlessman |
Looking at the torque charts for an X1 they all seem to show a real drop off at fairly low revs (3k +/-) and then a recovery as the revs climb. Is there a "fix" for this through software? Did Buell deal with this in later model X1's or does it get fixed with some kind of aftermarket wizardry? | ||
| Whatsabuell |
well someone else my respond and call me stupid but i believe that is do to the cams in the x1 not the efi you may be able to get some of it out the programing, i dont know. | ||
| Buellboiler |
Without checking for sure, I believe that emissions restrictions may be the culprit for the dreaded flatspot around 3k. This is one of the advertised advantages of the 'race only' EFI controller and other aftermarket ECMs. In general cams do not produce a deadspot in the torque curve. They can be designed to maximize higher rpm performance with lob overlap and can be advanced or retarded depending upon your goals. The fuel carve is most likely to produce a flatspot in the HP/torque curves, which is controlled by the ECM. | ||
| Hootowl |
The cams are in play, but not as significant as the exhaust. If I remember correctly, it is due to the exhaust/cam combination being set up for high RPM torque peak. The muffler is tuned to make high RPM power while still being quiet. The resonator tubes in the muffler set up reversions that hurt the midrange. An aftermarket muffler fixes this. You'll also need the race ECM if you change the exhaust. If you look at dyno charts for various aftermarket systems, they really don't gain much peak power vs. stock. All the gains are in the midrange. | ||
| Sloppy |
To fix the dip really requires the Race Header; the Race ECM and muffler does help, but it's the header that removes that dip. And, yes, that's spoken from experience...  | ||
| Phelan |
What they are saying is the only way to TRULY fix it is aftermarket exhaust, ignition, air cleaner, cams, and a good tune  . | ||
| Jos51700 |
The torque dip on X1's is common to all high-overlap cam, open-plenum v-twin engines. This torque dip is exactly why there is an exhaust valve in the muffler on XB12's. However, a large number of X1's came from the factory with incorrect ignition (and therefore fuel) timing. This is a major cause of the hole in power delivery on X1's, and many a customer gains a new sense of pride in their bike after the timing is set properly. Try it. I'm willing to wager that it's off by quite a bit, and properly setting timing will make you smile and forget about the rest. | ||
| Kalali |
All I can say is that changing the fuel/timing maps to Race ECM specs (loaded the maps on my stock ECM) and a V&H Slip-on made a great difference in how the bike "pulled" in that 2500-3500RPM range. I don't have any data to back up this claim but the difference in "feel" was pronounced, not mentioning the improvement in sound which was worth the change all by itself. | ||
| Oldog |
Look in the KV I posted some dyno curves for a stock and modded X1 |
