| Author | Message | ||
     Zoedogg1 |
Since adding my race ECM, Jardine pipe, and K&N filter, I have noticed that it is a whole lot easier to get the rpm's up much faster. The problem is that the same is true in 5th gear. At 110 mph I notice that I've only got about 2000 or less more rpm's to play with. Have I sacrificed my top end? Just curious, cause everyone knows we have little to no business taking corners at 130 mph or even straight aways for that matter."Thats the responsible person in me...ignore him".  | ||
| Swordsman |
Shouldn't that RPM count be the same no matter what your HP specs are? Tuning isn't going to change gear ratios....? ~SM | ||
| Zoedogg1 |
Thats what I figure also, but can the air/fuel ratio change this? | ||
| Xl1200r |
Your gear ratios aren't going to change. Whatever you think has changed in terms of your top speed is totally in your head. | ||
| Mnbueller |
Now I will start off with saying I don't know how it is configured but...Could your Race ECM be setup to read the speed incorrectly. So it makes the speedo say 110, when you are really only doing 85...Just a thought. | ||
| Darthane |
There's no reason for a Buell stock vs race ECM to have any different algorithms for calculating speed. Speed is taken off the transmission output shaft - nothing short of a gearing change is going to effect the engine RPM to wheel speed ratio. | ||
| Zoedogg1 |
LOL..or maybe I have the fastest buell ever and Im doin 200 mph.lol Joking..It probably is in my head..Im gettin old these days...  | ||
| Swordsman |
"Your gear ratios aren't going to change. Whatever you think has changed in terms of your top speed is totally in your head." Well, his top speed could definitely be lower due to a bad tune, BUT his RPMs will be lower as well. There's the problem w/ his original theory.  ~SM | ||
| Ikeman |
Clutch slipping? That'd give you more RPMs without the speed. Just thinkin' out loud... | ||
| No_rice |
bang the revlimiter in 5th and see what it does. i guess you will know then. i havent pegged out the xb since last year, but i know on the 1125 at 6000 rpms in 6th gear is right at 100mph. that leaves 4,500 to make up that other 70 +/- mph. your only looking for 25/30 mph maximum in the 2000 rpms you have left. it will do it, ring its neck! | ||
| Blake |
Some math... ![: ]](http://www.badweatherbikers.com/buell/clipart/proud.gif) 110mph*(6800rpm/4800rpm) = 155 mph. So if your XB12R drivetrain is OEM/stock configuration then your "or less" appraisal of the situation is accurate. For a stock/OEM drivetrain at 110 mph in 5th gear, your XB12 engine should be spinning at around... (110mph/135mph)*6800rpm = 5540 rpm Tim's 1125R is right on the money... (10500rpm/6000rpm)*100mph = 175 mph | ||
| Zoedogg1 |
Your right...Im koookin out I guess. Now that I look at the math, I'd like to delete this whole thread....Thanks guys!! | ||
| Beachbuell |
I had the Buell Race Kit (pipe, ECM, air filter)installed on my 2004 XB12R and it would top out at an indicated 147mph before hitting rev limiter. | ||
| Darthane |
"indicated 147mph" Heh...get a GPS that can give you actual speed and see what the difference is. Our speedos are - shall I say - 'optimistic'.  I don't think I've ever hit the limiter on my 9 in 5th gear...highest I've ever gotten to was about 120 indicated at Milan dragway, which was more than fast enough for me! | ||
| Mesafirebolt |
I have never had an issue being able to bang the rev limiter in 5th. My speedo says 142 and so does my GPS??? DO NOT forget, different tires have different outer diameters...that affects the overall gear ratio and top speed | ||
| Darthane |
True, that. The Metzelers I have on the bike now have a taller profile and are likely much better in terms of indicated versus actual speeds...the D207s that the bike came with (and the D208s they were replaced with) had a pretty squat profile and were off by a fair margin once you got into the higher speeds. ...they all come with some variety of Pirelli nowadays, don't they? I'm not sure how those profiles compare to the older Dunlops. (Message edited by darthane on April 23, 2008) | ||
| New12r |
Your bike is geared to 140mph at redline. My old bolt had no problem getting there, The uly is another story. |
