Tuning advice sought -

[Barry Tisdale]

As a relative newbie to efi, chips and such, I'd like any and all feedback
as to my thinking, methods, etc.  Especially correct me if I'm wrong
somewhere.  Thanks.

Trying to develop a good 40# chip for my modded Syclone, 749 ECU.  Mods =
heads, cam, turbo and all the hardware needed to monitor stuff and to
assure adequate fuel flow.

Started w/ a good 18# 3 bar strip chip, was running fairly well; did the
cam & heads & turbo upgrade (21g comp x 10cm° turbine).

First off, burned a bunch of chips changing only the BPW vs EGR value @ 0°
desired EGR - all the other values zeroed for simplicity, no EGR's going to
be used anyhow.  Closest thing to an injector constant, I'm told.  BTW,
zeroing the "Injector constant" value in the 749 has *no* effect on anyting
- apparently the code doesn't use it.

The value that gave the best combo of idle quality & cruise INT closest to
128 turned out to be 0.94.  I was using 44# base FP, but was getting
constant knock above 4800 rpms, 18# boost; injector duty cycle was 100%.
This is probably a bassackwards way to start, WOT stuff, but caution was
observed, nothing broke.  Reason I did this was that I figured the FP gives
a nice, straight "curve" to the fueling (actually flat curve), so was the
place to start.  Do everything else, find oyt the WOT fuel's inadequate,
start over.  Phooy.

Raised the FP to 48#, which should give a 6% increase in flow.  High rpm
knock down to 2°.  Ok, I like that.  Now, seems to me the next table to
adjust is the F30, VE vs RPM, for a broad "overall" curve.  The injectors
turned out to be quite "fat" down low, so VE's @ 0, 400 & 800 RPMs were
reduced so's to get around 128 INT @ idle.  Starting was crappy, needed to
richen up the CRANK A/F to get decent starts.  The reduced F30 value @ 0
RPM probably partially caused this.  Raised VEs @ around 3200 - 3600 RPMs,
figuring this was the approximate torque peak; tailed off from there, from
4000 up, figuring torque was past, flow probably falling somewhat.  This
table, I figure, should somewhat resemble a smooth curve.  ?????

Next to do is the VE vs RPM vs MAP table; my thinking is that this will
provide the narrow band "tweaks" needed here and there to get good throttle
response, off idle, etc.  Working on this part now.

Got a question: if the VE vs RPM vs MAP table apparently covers just about
every situation, of what use is the "Base boost multiplier vs MAP" table?

Anyting I'm not considering, comments, etc. *very* welcome.  Had a dismal
day @ the track yesterday - best of 13.06 @ 105 MPH, was expecting far
better considering the time & $$$ in this thing.....{:{E.  The launches
were poor, bogging, missing, etc, so this chip has gotta be improved.

Thanks for any & all input - Barry


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