Scooterotica

Knowledge wrote:Well, it's good to see a bit of healthy debate, and it's nice to see that some people actually read to the end of my longer contrubutions.

I don't know Charlie, and he is fairly enigmatic, so perhaps I was wrong to imply that I knew how he worked, but I needed someone to illustrate the computer age of tuning. I know that he uses computers, because Tony told me he did. In fact Tony, you were the one who told me that computer based tuning was THE future. So, back to the offending line....

Frankly, much of his innovation is driven by what his computer is suggesting.

Let me say first that I was not saying that Charlie was incapable of innovation without a computer, so I will clarify this sentence.

If I had a sophisticated computer programme that accurately reflected my previous experiments and complimented the results from the dyno and testing, I would use the programme to make changes to my engine within cyber-space. Now, if my programme told me, say, to lower the primary compression ratio, I would have to look at innovations that would allow me to do this within the rules.

So, the sentence could have been less person-specific, but this is how innovation can be driven by what a computer is suggesting.

davidblythe wrote:this thread has all the elements of a Greek play with layers off allegory,

the siren calls, hubris, nemesis, the jouney to Hades

hopefully Zeus is mindful of the role he gives to Hermes

Knowledge wrote:So that matter is over. Now where were we ........?

cezeta wrote:is it you that makes the choke cables and brake cables for jb tuning?

J1MS wrote:It seems there are several producers of high tech dynos with the ability for pressure analyzers to be used with many available functions which allow a window into the working cycle of a two stroke engine, I have read up on a few dynos through the Internet...
I was originally looking to see if anyone in the scooter-world had published anything dyno based for crankcase pressures, combustion pressures, and exhaust port pressures on a one cycle basis, as I had already heard of this going on in the other realms of two stroke tuning.
I would have thought the primary pumping pressures would be of around 3-10psi for the crank case at or just after transfers opening.. More of an "uneducated guess"...
Combustion pressures are dependant on compression ratios, ignition timing, cylinder temperature, port timings, so for this reason cylinder pressure would be harder for me to make a calculated guess..
The negative and positive pressure waves reverberating through the expansion chamber effecting exhaust port pressure as the port opens and closes I had an "uneducated guess" at around minus 5-16psi with a reverse pulse peaking at around plus 3 to plus 14psi..
this was my thinking and I was looking to see if anyone had managed to put a tuned Lambretta on a suitable dyno to see if my guesses came close...
As I say just trying to see if my thinking was right but wasn't sure if this was being done in the Lambretta Vespa tuning circles

Here http://www.tfxengine.com/software8.html" onclick="window.open(this.href);return false; is a link to a Dyno website with some data which explains in fairly good detail in graph form combustion pressure psi, combustion rate/fraction burned and exhaust port pressure psi
The fact I am looking at this stuff Does not make me a tuner I just know it exists and this kind of stuff is way beyond my capabilitys I just like to know how the performance gains could be made...