| Author | Message | ||
     Cronan128 |
i race an xb 12 and was wondering if anyone knows of a larger throttle body that is available or what road race guys use for this... | ||
| Slaughter |
You can have the TB bored to something like 51mm. No point unless you really have bigger valves and cams that NEED that much more flow. I have the bored XB12 TB on my XB(1169) | ||
| Buelldyno_guy |
According to Buell sources the single biggest limit to the XB, or non XBRR engine is the TB flow. XB Stage 3 Heads can out flow any single throat TB. The RR changed the location and shape of the heads getting the intake ports wider apart an changing the angle to fit the two 62mm units. Steve is right on about boring the single 49 to just short of 52mm. That's standard on all of our 90. inch and anything on the track. We do have one other little thing we do, as it doesn't make much sense to us to try and suck 52mm of air through a 49mm rubber straw. Terry Parsley - JT&S Performance | ||
| Benm2 |
 How about these? | ||
| Slaughter |
Yabbut you stillhave to get them to turn the corner into the intake... any design is going to be limited in the XB/Sporty/EVO head as-built. | ||
| Benm2 |
Well, sorta. If you take the "hump" in the intake tract back to the flange mount, then oval-out the port, then you can kinda increase the angle. Remember the pre-XBRR FX bikes had a dual-intake that used stock (modified) XB heads. | ||
| Slaughter |
Hmmmmm... (scratches chin) I can see where that might be better. | ||
| Buelldyno_guy |
Part of what made the RR work was the change in deck height of the cylinders even thought they were still at 45Deg they were longer than stock. This moved the intake ports higher up the V and thus wider apart. I found a TB with twin 45's and it's overall size would allow it to fit between the heads if twisted just a little the manifold/injector lay-out would need some development work, But so many projects and so little time. Terry - JT&S Performance | ||
| Benm2 |
The RR ports also had NO accomodation for side-draft setups, that the XB heads still have. It looked like you could roll a baseball into the RR combustion chamber from the airbox! | ||
| Jadow |
Where can I find pics and info on the Pre-XBRR FX bike? I have always thought there is room for improvement ie individual throttle bodies. What other manufacture in performance uses a single inlet? |
