On ktmtalk.com there is a huuuuge thread on this subject, lots of controversy also.
https://ktmtalk.com/showthread.php?5...-System/page46
The opinion of Jeb, the administrator (see posting nr 434) :
I agree with him, TPI is here to stay.
On ktmtalk.com there is a huuuuge thread on this subject, lots of controversy also.
https://ktmtalk.com/showthread.php?5...-System/page46
The opinion of Jeb, the administrator (see posting nr 434) :
I agree with him, TPI is here to stay.
I was on KTM talk for a while, started a twostroke injection thread to discus TPI and other injection methods, pros and cons, I got savaged. So I keep my opinion to myself, Ill let there 'intellectuals' fight it out amongst themselves. I might add, experts who had done nothing themselves.
Flettner was running TPI before KTM. Basically KTM dismissed Flettner's experienced input and they pursued other more complex EFI ideas that ultimately did not work. Before trying to copy and then patient for themselves Flettner's TPI system. KTM's patent application failed because it was Flettner's original idea and he had proven its viability.
.... KTM's progression of development.
..... Flettner's TPI system, maybe about 2 years before KTM's.
Tried to patent it for themselves.
TM stopped them, prior knowledge.
Turbo small bore 2stroke.
Fun with 2strokes does not have to be expensive. 8's on a mini bike!!! I think that would be faster than the Kawasaki 500 triple I had.
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I wanted to refine my EFI Pseudo MAP program and have been spending some of my time in CV19 lockdown developing an Arduino Nano setup to simulate the crankcase pressure wave I recorded from bike.
Common MAP pressure sensors display their reading in discreet 1ms output's not as a continuous analog line. I needed to simulate this so that I can then use the simulated 1ms output to develop and test the new crankcase pressure reading Pseudo MAP program.
This is the reading I recorded from the crankcase pressure sensor on my bike at 4k RPM. The yellow dot is the ignition trigger and the highest crankcase pressure is at BDC, the lowest at TDC. The idea is that changes in mass air flow through the motor can be determined by changes in the Delta between highest/lowest pressures.
This is the simulation program at 4k RPM. The simulation sweeps from 1k RPM to 13k RPM and at 12k there is only five 1ms pressure readings.
The aim is to use this simulator so I can refine my Pseudo MAP program without having to run the bike.
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Actual crankcase MAP sensor readings at idle 1.8k rpm, and 4k rpm and 10k rpm.
MAP sensor, Blue line. 500mV a division. 0-5V = 0-2.5 bar MAP sensor. The MAP sensor has a 1ms settling time which is common for these types of sensor.
Interestingly, at idle the crankcase pressure rapidly drops at TPO transfer port opening but at higher rpm and load this is not happening.
Ive not heard from Fabio for some time. At one point he was not very well.
Mk2? Work gets done on it when time and money are available, slow lately. Although this latest lockdown has meant some progress. Apart from finishing an air filter system its ready for some track time somewhere.
I can't seem to find picture now.
There was a picture of the team bike where the throttle body was just hanging there, clearly showing 2 injectors mounted to bottom of TB. The stock TPI injectors are still in place, but apparently have a dummy hose connecting the two together.
The TPI I believe currently works decent for a few reasons. "A" port doesn't receive the bulk of fuel, less short circuiting. Downward position in B helps with mixture motion.
TPI for 50% and under, TBI FOR 50% and over may be the best power solution. 4 injectors for each cylinder
DI also run TBI to assist with high speed operation, perhaps thats what KTM are trying.
Im all in for four injectors but in the A and B ports. Blend the A injectors in, as appropriate, when gas inertia warrants it. Way more accurite fueling and easier to impliment 'skip cycle' injection traction control. True traction control not just shitty retarding the ignition. Way more likely to waste unburt fuel out the exhaust with only TBI.
To me Mk2 TPI makes sense but Im no motorcyle manufacturer. Im looking further ahead with this skip cycle, I guess they are concerned with charge cooling into the crankcase and perhaps better oil transmission to the bigend. I believe Ive sorted the bigend oiling / bearing cooling issue and heavily water cooled crankcase.
Fu$%king rubbish carburetors, who needs them.
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