Newbie needs explanation...

[David A. Cooley]

At 12:16 PM 12/20/98 -0500, you wrote:
>Bruce -
>
>Thanks for the reply; things are sort of like I figured.
>
>According to a GM spec sheet I got, BPW (Base Pulse Width) is the *result* 
>of a calculation w/ several multipliers.  Guess I don't understand this, 
>then.  When running a scan tool, I get BPW (units = milliseconds) readings 
>of from zero (on deceleration), to 19 @ WOT & hi rpm.  (I was wrong w/ the 
>15 figure on my last post).
>

Sounds normal

>Are these figures consistant w/ what you'd expect?  The 19 figure came @ 
>4050rpm, the highest speed reached (this thing shifts @ too *low* an rpm - 
>gotta fix that!).  At this speed, we have 14.8msec/crank revolution - duty 
>cycle comes out to be *more* than 100%...?????  If we figure on two crank 
>revs per power cycle, 19msec / 29.6msec = 64% duty cycle - this makes more 
>sense to me.
>

Yep... 64% is the correct figure.

>Before I start playing w/ this thing, I've got to *understand* exactly what 
>I'm doing and how it works in stock trim - lean mix on a turbo engine can 
>mean sudden death, and I *really* don't want that to happen!!

Check over at the Syty web site for the addres of the Syty email list.  Web
site is: http://www.syty.org/
They've already hacked the code in the chip and have TONS of great info and
know what works and what grenades motors!
One thing you don't want to do on the STOCK (internally) Syty engine is
raise the RPM's... it's a workhorse designed to be all done by 4500 RPM.
Unless you change cam/lifters/valve springs and pistons (Stock pistons are
very weak) you're limited to where your at now with RPM range, but HP &
torque can be bumped tremendously in these ranges.
Just don't be fooled into trying to think of this engine as a small block
chevy and try the same patterns of things that make the SBC run harder...
they don't work.  For the SYty (And buick GN motors too) to make them run
right there is a combination of things that make them run right... leave
out one item of the combo and you either see no improvement or actually
reduce performance.
Later,
Dave


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           David Cooley N5XMT           Internet: N5XMT at bellsouth.net
     Packet: N5XMT at KQ4LO.#INT.NC.USA.NA   T.A.P.R. Member #7068
       I am Pentium of Borg...division is futile...you will be approximated.
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