turbo and WOT injector

Jörgen Karlsson jurg at pp.sbbs.se
Sat Aug 26 02:37:01 EDT 2000


>
> Wow, this is a pretty interesting system ... I wonder if there are any
> "members" in the USA?  I also thought it was interesting to see a familiar
> name there ... Lehmann.  I don't know if there is any relationship to the
> Lehmann of Audi renown though ...
>
> As long as you are using the thing to enrich a stock fuel system I doubt
> that the fact that the 5 cylinder configuration is not explicitly
> cited will
> be a problem.  It was interesting to see that they had full EFI/spark
> "Motronic" systems as well ... but I didn't see any mention of having a
> knock sensor input ...
>

I must admit that I didn't even think about them not mentioning five
cylinder engines, but as you say it will not make a difference on the
additional fuel controller (Turbo Fueller). I do think that it accepts five
cylinder engines anyway, I will give it a try next time i fool around with
it. All their other stuff works with five cylinder engines even if it is not
mentioned int their manuals either. I am talking about the EC, MIC3 and PEC.
I know a way to get these to work with a knock sensor, it can use an
external trigger to switch programs while the enigine is running. This can
be done by the knock sensor with a simple circuit, their PEC has a very nice
feature, it can adjust mixture balance between cylinders, we need this on
our cars...

Knock sensors on aftermarket controllers are not very common, these systems
are usually used on tuned vehicles where a knock sensor usually only causes
problems. Haltech that are often used in small series production vehicles
can use a knock sensor. I have only had problems with the knock sensor on my
car, i will only use the knock sensor to drive an indicator light, a simple
timer circuit will make this possible.

The use of a O2 sensor for closed loop operation are more common even if
many of the race oriented manufacturers don't impliment it. Your car will
work _much_ better without closed loop, closed loop generally mean that the
mixture oscillate between a too rich and a too lean mixture. This is because
the sensor interface in the ecu only recognizes these conditions, this in
turn is because the sensors only well defined outputs are rich or lean.
Because of this; if the ecu see a lean condition it will richen the mixture
until it sees a rich condition and then because it dont know how rich the
mixture is, it will have to lean out the mixture until it sees a lean
mixture again....

The new generation of aftermarket engine management systems use a 'wide band
o2 sensor' these sensors can show other (well defined) values then rich and
lean, these engine controllers, with SpeedPro at the top, can regulate the
mixture very precisely, within 1/2 AFR point is normal. Unfortunally
Speedpro is not available for five cylinder engines, this system is very
very very easy to tune, you decide on the mixture for the loadsite and the
computer tunes for this mixture. This is because SpeedPro has the WOT Closed
loop ability, this mean that it uses the o2 sensor to get the right mixture
at all load sites.

My favorite system for our cars are EMS www.enginemanagementsystems.com,
this system are known for its very simple tuning procedure, I think that it
is the most important feature in an aftermarket system. It is not capable of
closed loop operation, can not use a knock sensor but it has a wide band
lambda sensor that is used for tuning. It can be tuned with either a
handheld 'smart interface' or a PC computer.

Jörgen Karlsson
Gothenburg, Sweden




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