"Ray Block" <BPracing@wowway.com> wrote:
[...]
> Most of today's OEM EFI systems use mass air for this reason. [...]
That surprised me. My information may be out of date, but the
last time I checked, Ford was just about the only company using MAF.
Maybe a lot of the imports are using it?
[...]
> Summary:
> Most aftermarket EFI systems use Speed Density because it’s easy to program,
> fairly cheap, and works very well with any size engine. Alpha-N is only for
> racing. Mass Air is very good for smaller engines that don’t need larger
> throttle bodies."
Yep, it makes sense for the aftermarket EFI systems to use speed
density because (for the most part) they are designed to be easy to
configure. You can slap the same aftermarket EFI system on just about
any engine and make it work because you can modify pretty much all of
the parameters. So, even if in theory a MAF setup could compensate
automatically to engine modifications, when you have access to the
computer to precisely tune it, that's not as much as an advantage as
it might be with say, a locked down OEM system. Adding to that the
lower cost of speed density and not having to deal with delicate MAF
sensors, using speed density for aftermarket systems is pretty much a
no brainer.
For the same reasons, speed density is pretty much a no brainer
for OEMs as well, because they don't really care about engine
modifications. They have just as much access to tune their computers
as enthusiasts do with an aftermarket EFI system, so they can set it
up for the engine they are producing and it works fine for them. If
the customer makes changes, that is not the OEM's problem.
> -----------
> Hope you found this interesting, Mike. In a nut shell, there's nothing
> wrong with the Speed Density systems Mopar uses. You would be surprised
> how far you can go with engine mods on a emissions legal MP PCM if you
> choose your parts carefully. Just look at the mods I've made to my Dak at
> the link below....and mine is considered mild compared to several of the Dak
> racers I know who are way quicker than I.
Yep, it would be nice if the Mopar computers were as user friendly
as some of the Chevy and Ford systems, but there is certainly a lot
that can be done within the parameters of the stock (or Mopar
Performance) computers. Custom flashes are available from various
sources as well for more radical setups. These are more expensive
than modifications to Chevy or Ford computers, but at least there is
an option available, should someone be looking to squeeze everything
they can out of their setup.
--
-Jon-
.- Jon Steiger -- jon@dakota-truck.net or jon@jonsteiger.com -.
| '96 Kolb Firefly, '96 Suzuki Intruder, Miscellaneous Mopars |
`-------------------------------- http://www.jonsteiger.com --'
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