Texas Two Step Taco
- Thread starter Texasstar
- Start date
That sounded much cleaner than before.
Can you fit a set of clubman bars to move the bar position further forward? Or cut the clipons to a suitable length, mount the bars pointing forwards and then weld a set of drag bars across the stubs. It would give you more room to straighten up/stretch out a bit and would help to keep weight on the front wheel.
Can you fit a set of clubman bars to move the bar position further forward? Or cut the clipons to a suitable length, mount the bars pointing forwards and then weld a set of drag bars across the stubs. It would give you more room to straighten up/stretch out a bit and would help to keep weight on the front wheel.
Texasstar
Can't is a four letter dirty word
I see what you mean. My MX bike as a kid had a goose 10 speed neck that moved the bars out and forward
Need to be about a foot lower in the center of the bike also
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John Murray
Been Around the Block
How does it feel, performance wise? How much throttle were you giving it?
Have you thought about fitting a silencer so you can start it at home without annoying the neighbors? Make it big so it reduces the noise effectively, the weight won't matter if you remove it for racing.
Have you thought about fitting a silencer so you can start it at home without annoying the neighbors? Make it big so it reduces the noise effectively, the weight won't matter if you remove it for racing.
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Just shorten the rear struts as far as possible and drop the forks a little more - you will probably have to fit super stiff springs to avoid contact at the front end.. Maybe use a lower profile sticky street tire to drop the back end as far as possible/practical. The chain will start to rub on the lower side of the swingarm pivot. A larger pair of sprockets might help with that.
John Murray
Been Around the Block
John Murray
Been Around the Block
No. Not that I don't think they have their place, but for my Metralla project I measure and record very few things - rpm, torque mainly, plus of course timing and fueling and anything out of the ordinary that occurs. I keep notes for each run whether on the dyno or on the salt. Years ago I would also measure CHT and EGT but I eventually realised I was doing it back-to-front - the EGT in particular should be noted after the best performance has been found, and used as a sort of GPS location to home in on if you get lost at a later date.
I think we need to remember the reason we do all this work is to get the highest possible readings on the torque and rpm gauges - anything else is incidental and only serves to lure us down wrong tracks. The other thing we need to remember is that our engines are basically useless outside of a very narrow rpm range. It might make them harder to ride but on the other hand it means we have the luxury of tuning what are very nearly single speed engines. So we have no need for complex timing curves (or often any curve at all) or fancy fuel curves. We go straight to peak rpms at the start line and stay there til the finish line, it's that simple.
Having said that I have come across issues on the track that didn't show up on the dyno, and these might have been resolved more quickly with datalogging. But I like to keep things simple and free from things that might distract me from the torque gauge.
Short answer: no I don't but I would if the application required it.
Texasstar
Can't is a four letter dirty word
Being at the drag strip with these guys I have learned they are looking at tire and clutch slippage. True first thing they do after looking at the slip is go plug into the computer. They are at the top of their game.
Now that we know the bike will launch with the big tire we will see if the clutch will hold up.
I know with this gearing I was shifting into 4th at the 1/8 mile before and that was 68mph. Getting in 4th way before that is not a problem now. I don’t think Zeke will catch us if our 60’ time is there. He mumbled something about losing and damn that is quick. Probably just wants me to be overconfident. Lol
The rear brake rear set needs a better tab welded to the frame than the stock tab. It is flexing and the rear brake is worthless at the moment:
Need to mount the shift light and BB says we don’t need a tach to launch it.
I will save the data logger for advanced tuning if we need it later.
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Now that we know the bike will launch with the big tire we will see if the clutch will hold up.
I know with this gearing I was shifting into 4th at the 1/8 mile before and that was 68mph. Getting in 4th way before that is not a problem now. I don’t think Zeke will catch us if our 60’ time is there. He mumbled something about losing and damn that is quick. Probably just wants me to be overconfident. Lol
The rear brake rear set needs a better tab welded to the frame than the stock tab. It is flexing and the rear brake is worthless at the moment:
Need to mount the shift light and BB says we don’t need a tach to launch it.
I will save the data logger for advanced tuning if we need it later.
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BB is at the top end of drag racers worldwide and his bike runs in the sevens. To do that consistently he, and others, need to understand and control every variable from weather to slip and so on. As John mentioned, EGT is a number they understand from hours on the dyno.
I used data logging when I set up the GT because it helped me to see how inconsistent I was, but I removed it because it was just another distraction when I needed to focus on set up and my riding. The truth is that a better rider on my bike would probably/definitely be much faster than I am and without any of the distractions. Focus on making it run cleanly and practice the launch. Don't waste more time in the first 60 feet than could ever be made up at the deep end.
I used data logging when I set up the GT because it helped me to see how inconsistent I was, but I removed it because it was just another distraction when I needed to focus on set up and my riding. The truth is that a better rider on my bike would probably/definitely be much faster than I am and without any of the distractions. Focus on making it run cleanly and practice the launch. Don't waste more time in the first 60 feet than could ever be made up at the deep end.
Texasstar
Can't is a four letter dirty word
Thanks Teazer. I am going to put the training wheels (wheelie bars) on to practice the launch since we are going old school.
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Texasstar
Can't is a four letter dirty word
We don’t quit at a T-shirt
We haven’t even started dyno testing. I have u4.4. Need to build your chamber but the air is cool in Texas and the track is open Want to get a baseline for 20:1 c:12 and see where we are on the track. Get some practice and see how our clutch holds up. Then tune for the 32:1 U4.4.
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John Murray
Been Around the Block
My thoughts exactly, and if I were to go drag racing this is where I'd spend my time. I'd get a box full of clutch disks and find somewhere to practice launches until I was consistently quick off the line. Pick the low hanging fruit first.
The Bandera probably isn't all that different to my Metralla when it was in air-cooled street trim. It had a much smaller tire though, and I felt that the little bit of slip off the line made it easier to launch. Despite the small tire though it would carry the front just clear of the ground through the first three gears. I got so used to dealing with this with weight shifting that I wouldn't even realize it was happening unless someone else pointed it out.
John Murray
Been Around the Block
I agree with BB - I don't think you need a shift light or a tach. These things are basically a single speed engine and it's very obvious whether it's in it's usable rev range or not. Don't be afraid to rev it past its peak when leaving the line - the flywheel energy will help you launch and the load that's applied when you release the clutch will soon pull it down to the torque peak. I think the key will be to have enough launch experience to know exactly what to do and to do it instinctively.
Texasstar
Can't is a four letter dirty word
This is what I practiced that first couple of times, pull to the line, load the clutch, half throttle off the line to see what it would do. Smiled because the rotor had enough momentum to turn the big tire.
Now to put it on the rev limiter and do the same thing but be on the pipe and stay there. It’s all clutch and not letting go of that last 10% too quickly. Repetition.
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