OK, the idea behind a spacer goes back to the carb days. The idea was to put
a spacer under the carb to give the intake more internal volume. This also
lengthened the runners on the intake making the ram effect even more. The
spacers also worked best on a single plane manifold. Then entered the
Throttle Body Injection system (TBI). It is basically a fuel injected carb.
A spacer under it would act like the spacer under a carb, thus more power.
Multi-Point Fuel Injection then enters. MPI can use two systems, either mass
air flow or the system used on the Dakota/Rams (I forget the name). The mass
air flow actually measures the amount of air entering the system, whereas
ours takes sensor readings (map, IAT, TPS, O2, etc..) and use a preset fuel
table to determine the amount of fuel needed. If your spacer did manage to
use the ram effect and introduce more air into the cylinder with the same
amount of fuel as if the spacer were not there, then the mixture would lean
out. Modern motors already run lean, so therefore you would be going even
further on the lean side, creating more heat and possibly doing damage to the
internals of your motor. Supposedly you say that the spacer is after all the
sensors, well you forgot about a few there. The IAT sensor is in the
manifold and then you can't get around the O2 sensors. If they sense the
exhaust is indicative of a lean mixture, then they signal the SBEC to richen
the mixture. Then you are back at the proper a/f ratio. So essentially you
have gone from stock a/f (which is already lean by nature), to an even leaner
ratio, to the O2 sensors talking to the SBEC, to the stock a/f ratio again.
However you are now packing the cylinders with more air, therefore more fuel
must be used. If you don't think that the computer can do that, then how can
Bernd put 9# of boost in his intake and the computer now know that?
Computers are designed to sense just about everything that happens in that
motor, and they are also designed to correct some of the problems that it
senses. Thus, while you may get some extra power (which could be a dyno
brainfart), is it really worth all that money? I would rather take that
money and look at some other option (JBA, TB, NOS, etc...) That is my take,
and I am outta here.
Will
96 Cylindrically Challenged (Anemic my A**!!!) V-6
This archive was generated by hypermail 2b29 : Fri Jun 20 2003 - 11:56:07 EDT