Couple more pics of the TM 300 Fi engine
This one shows the innovative injector positioning, the finned alternator cover and the starter motor
And another bit of electrical consumption...exhaust power valve.
Cheers, Daryl.
We've all seen it, and TZ350 gave a perfect explanation. The simplest thing to try is give the engine a fistful of ignition advance, like 30* before TDC, in the problem area. But make sure the ignition timing is back to normal (somewhere around 16* bTDC) in the powerband.
Thanks Frits
Just a bit strange, before rebuild, resleeve, etc. we didn`t have the drop and had 151HP on the dyno. Now there is a huge drop and we do 141HP.
We increased ex duration from 200 to 204 and was aiming for more HP at 9500, we had 151 at 8900 rpm.
So with more ex duration I would expect lack at the bottom but perhaps a bit more in the top. Transfer are 130 pipe TL is the same.
EGT in header is 520 C so a bit cold.....
Ignition in the problem area is 30* and doesn`t affect the drop very much....
Attached are dyno of before and after rebuild.
Is this H2 a drag bike?
200ex is very high. 204 is ouch.
Anything over 196 is a band aid and more thought needs to be done on cylinders.
What kind of dyno? Yours? Is tire slip an issue?
Yes, it is a dragbike
Yes, it is my dyno. I have made the dyno myself, using software from Performance Trends.
No, tire slip is not an issue.
As I said, we used to have 200* and was recommended 204* more as an area issue more then duration to gain more HP. Peak rpm should be adjusted by the pipe.
To be honest I am also sceptic about 200* + duration but perhaps Frits can make a comment on that.
Well then, why worry?
The only time you will be possibly driving through the torque dip range will be getting to the racing line and then back to the starting line.
However, from the shape of the two curves, it seems like there are some things significantly different between the setup before the rebuild and now.
For sure, a lot can be learned If you take the painful route of finding the differences and take your time to find out the impact of every single one of them.
You were obviously right about expecting lack at the bottom. That you got less top end power instead of more is not too surprising. I used to own a couple of Kawa H2s, and both the blowdown angle.area of the single exhaust port and the angle.area of the four flat transfers left a lot to be desired (and the top-hat combustion chamber shape was sh*t as well).
Maximum power at 8900 rpm is not bad at all, but the engine will definitely run out of breath above that, even if you raise the exhaust timing to 204*. This may increase the blowdown angle.area but it does nothing for the transfer angle.area. And what about the inlet side? You'd need 48mm carbs for the revs you're aiming at...
Moreover, raising the exhaust timing moves it further away from the 190* that is optimal for wave superposition and it provides stronger initial pulses that are more capable of messing everything up at around 2/3 of the maximum torque rpm. I'd say: don't be too greedy and go back to max.power @ 8900 rpm.
So,, we?ve been dynoing a little.
And, Before dynosession i just set the powerjets one turn richer and the needles a couple of turns leaner, this due to it was very rich, and really rich on lower throttleopenings.
And with no adjustments on ignition(ignitech) it pulled 71.31hp on the fourth pull.
There are more to come, but we were happy at this point and didn?t want to push it while we were 'high on life'
Btw, Methanol ofcourse
https://www.youtube.com/watch?v=c3AlzA15Zw0
https://www.google.com/url?sa=t&sour...Nxc_qcqTH6T9jb
What is this shit? Rendered down snakes?
WOW you put Quantum Physics in your bike if you use it.
I think it has something to do with cold fusion![]()
Perhaps a descriptive name with a really memorable acronym, one that a major Corp is unlikely to appropriate.
Crankcase Resolution of Airflow & Pressure.
Parameters Of Oscillating Pressure.
Pressure Evaluating Numerically Iterated Simulation.
Measurements Inferring Localised Flow.
Mass Airflow States Tabulated Under Repeated Base And Top Exhalations.
All kidding aside... Great Work Tee Zee..
Cheers, Daryl
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