Chrysler systems? Anyone familiar?

[Edward J. Lansinger]

I am familiar with the Chrysler multi-point system used on the '84-'87
turbos.

If you do no modifications to improve airflow through your engine, then
your HP gains will be modest at best.  The OEM computer will already
be commanding ideal or close-to-ideal air/fuel ratios at wide-open-
throttle.  I'd have a hard time believing you could squeeze even an
additional 5%.  For wide-open throttle stuff, unless there is a big
problem with fuel distribution (which I doubt), just going to a
multi-point system won't make much difference.  You could tune
individual cylinders, but you're still only looking at a percent or two
per cylinder.

With no modifications directed at improving airflow, I'd guess your best bet
would be to concentrate on spark delivery for HP increases.  The SPI
system is (I'm sure) tuned for 87 octane gas, and conservatively
at that.  I don't believe that system tries to estimate octane rating.
So, if you're confident of the condition of the engine internally
and can guarantee you'll use your favorite high-octane flavor of fuel,
you could bump the WOT spark advance curve.  I'd guess you are looking at
an easy 5-10% gain.

If you do improve airflow, or change fuels, or just want to have fun,
then it makes perfect sense to modify the injection system.

- Ed Lansinger