Advice requested for choosing aftermarket EFI system

[Jacky Chu]

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I would not recommend the SDS. First of all, it's not really a 3D map. =
(i.e. lets say there are 10 rpm adj and 10 map adj. In a Haltech, there =
would be 100 adj points, SDS has only 20 adj points) It would be =
impossible for you to tune for best economy and best torque.=20
Second, you can't save map to computer. so if you have kids and thinks =
that the SDS is a gameboy. you might be stuck somewhere out in the =
middle of nowhere trying to remember the values that would make it run. =
Tuning is somewhat easier too if you can retrieve previous setting.
Third, the contruction of the unit does not give me the sense of a good =
quality built product. Would you depend on a product that uses 25 pins =
and 9 pins generic computer serial port connectors?

Jacky


  ----- Original Message -----=20
  From: Robert=20
  To: DIY_EFI at lists.diy-efi.org=20
  Sent: Tuesday, January 01, 2002 8:53 PM
  Subject: Advice requested for choosing aftermarket EFI system


  Hi All,
      I'm trying to decide on an aftermarket engine management system =
for my Motorhome, since I'm not learned enough to design my own, and =
there are several good commercial units available. I have, however =
designed and am currently testing a stand alone controller for the =
transmission. When I've got the bugs worked out of it, the next step is =
to install an engine management system that will allow me complete =
control of the engine.

      The subject is on a '92 Ford Super Duty chassis, 7.5L EFI V8, E4OD =
transmission, 17,000 lb GVW. With the exception of a Banks "Power Pack" =
4 in 1 long tube primary header exhaust and free flow intake system, and =
an "Aurora" high output inductive discharge ignition system, the engine =
is, and will likely remain stock. Ignition pick up is distributor hall =
effect sensor to a remote TFI module. It uses batch fired injectors =
mounted in the individual intake ports, 2 banks, 4 of 24 lb/hr injectors =
per bank.

      Normal operating range is between 1800 and 3000 RPM, but will =
occasionally pull down to 1500, and rev to 3600 to shift.

      This is not a high performance application, but rather a low =
compression ( 8.5:1 ) slow turning engine that will run heavily loaded =
much of the time. The object is to tune for best power under heavy load, =
and best economy at cruise, economy having a slightly higher priority.  =
Emissions issues are not a concern.

      I had originally only considered SDS www.sdsefi.com . They have a =
good reputation, and product support is without equal, but it lacks some =
features I would like, so I've been researching Halltech, Electromotive =
TEC II, and DTA. They are all fairly similar, but are different enough =
that I'm finding making comparisons a bit difficult.

      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?

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

  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?=20

  4 - Is there any advantage in tuning for use with 92 octane fuel as =
opposed to 87?=20

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

  Thanks in advance.
  Robert

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