all i gotta say is, people buy the pipe, they go past 38, that's it. no
equation can figure that one out and neither can u so ur wrong. and i do
have a stock cylinder, and i do go over 38 on flat. that's it.
>Subject: Re: Tomos Moped RPM limiter
>Date: Tue, 10 Oct 2000 23:10:35 -0700
> >I haven't been clear enough in my explanation. Apparently Steve's thinks
>that this limiter works on speed kits also. It does, but in a different
>way.. I thought that Mike did not replace the cylinder as he said he only
>mounted the tuned pipe, that why I explained he'll have problems going over
>38. The limiter is (as previously said) of a non-conventional type and is
>limiting the A5 to 8000 with STOCK cylinder and head ONLY. Due to the way
>works there is a point in which the preignition it controls, cylinder port
>time-area values and head compression just can't function properly and the
>engine boggs down. This happens at 8000 on stock.
>However, due to the fact that the 70 cc kit has different port time-area
>values and compression, the preignition point is satisfactory up to (as you
>have heard from Steve's) 9500+, but the limiter still limits the RPM, just
>at a different value. If someone was lead to believe otherwise, I'm sorry
>(the kit power issue is still topical). I personally have information that
>these ignitions make no problems on heavily modified manual speed Tomos
>mopeds even at 11000-12000 RPMs, but at these revs, the stator plate needs
>to be rotated (which I would strongly warn against doing on stock, because
>it won't idle afterwards).
>The more interesting thing is the nature of the A5's tampering protection.
>If you look at the "usual" US tuning procedure, you go for the tuned pipe
>the begining. When you realise you can't go over 38 (see above), you buy a
>complete speed kit. Now comes that problem with transfer ports (if we count
>out the base sealing problem resulting from the cylinder being designed and
>built for Puch rather than Tomos). So you file down the transfer channels
>far as possible and get real 50 mph. The revs are now at 10000, and the
>crankshaft is starting to complain. So you are thinking of further
>increasing the final transmission ratio. But there's no room neither on the
>rim or the engine.
>The A5 is always a step ahead :-)
> >P.S. Here's the formulae for calculating RPM value from speed:
> >RPM [1/s](Speed [m/s]*Total transmission ratio)/(PI*Tire radius [m])
> >The "relaxed" version:
> >RPM [1/min](Speed [km/h]*Total transmission ratio*60)/(PI*Tire radius
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