Advice requested for choosing aftermarket EFI system

Bruce nacelp at bright.net
Sat Jan 5 08:18:20 GMT 2002


    I'd really appreciate some opinions on experiences any of you may have
had with any of these manufacturers, as well as what features would be best
suited to my application. These questions, posed to some of the dealers were
met with unsatisfactory responses, or no response at all. They are as
follows.
Given the application;

1 - Is there any advantage in multi toothed crank angle sensors or 4 magnet
crank angle sensors as opposed to the stock hall effect distributor pick up?

For your use no.

2 - Is there any advantage to direct fire, waste spark ( 4 coils ) ignition
as opposed to distributor?

Coil near plug is the way to go, IMO.
It probably border line sounds crazy, but I think there is alot in allowing
the coil/coils cooling alot between firing cycles, keeps the primary
resistance lower.
A long the same lines, DIS is better then single coil.
The DIS and CNP eliminate the HV points of failure that a distributor has.

3 - Is there any advantage to sequential,  "semi-sequential"  ( cylinders
paired for ignition with paired injectors),  or batch fired every engine
revolution, as opposed to batch fired on alternate engine revolutions?

Only SEFI advantage at all is a small amount at idle, or when running huge
injectors at short durations at idle.   99% of the time the injectors are
just spraying fuel at the back of a closed intacke valve.

4 - Is there any advantage in tuning for use with 92 octane fuel as opposed
to 87?

IMO, YES.
I did fleet service of tow trucks, cop cars, recovery vehicles, and the
higher octane fueled vehicles always lasted longer.   Not 10-30 vehicles but
rather closer to 100 and millions of miles.

5 - Would it be better to use MAP, or TPS for load sensing?

Both.
My suggestion is find a hac'd ecm and work off of that.  I carry a spare ecm
in my car, cost $35.   Kill a aftermarket one, and just wait for UPS or Fed
Ex to drop off a replacement.  For racing, and rare street use the
aftermarkets have their place, for a work horse oem application, my money
would be on a modified stock one
Bruce

Thanks in advance.
Robert

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