Aussie ECU's

[Jörgen Karlsson]

Hi,

That explains it, I was sure that the SM2 could run closed loop.

The exhaust gas analyser give a far more correct reading then a Bosch LSM11
wideband sensor connected directly to the Motec.

The first downside of the Motec system is that the heater in the sensor is
not controlled. Then there are doubts about the trust one can put on their
sensor heat sensing circuit, there are even people who say that they dont do
any temperature correction.

You can datalog the analyser signal, at least on the SMC. I am sure that it
is possible on the SM2.

I have used the SpeedPro system that runs closed loop on all load sites, it
is great but I honestly perfer running with closed loop turned of or at
least limited to +/-5%. It is very hard to get the curve perfect with closed
loop, but then again it is very easy to get a very good result.

I know at least one race team that has blown a few $50k engines while using
Motecs closed loop operation. I think that it could be related to the same
problem I had with the SpeedPro. I would say that there are downsides to WOT
closed loop, not as long as you aren't stretching the limits but if you are
closing in on the limits you will have to be very careful.

Most new cars and probably all cars that are on the drawing board use WOT
closed loop. Examples are all new turbo volvos but the s/v40 models. Most
run the Bosch LSU sensor. It is very hard to reach the lowest emissions
requirements without closed loop. But these cars have perfect maps and only
use the closed loop operation to cancel out aging and tolerances. Several
hundred hours in the dyno is also helping.

Take a look at SpeedPro, they could have dual sensor options. They use the
UEGO controller and are very decently priced. No other system can compete
with their straight forward user interface. The system lack most of the
features for external equipment like boost control and things like that.
Remember that sequential operation is an option on the SpeedPro.

But I think that if you get an smc or an sm2 I think that you will be very
satisfied and it is almost for free too.

Jörgen


Hugh wrote:

I have previously asked Autronic about closed loop on the SM2 and although
it used to be an option, it is no longer.

Closed loop is offered on the SMC, but you have to also buy the separate
Exhaust gas analyzer. It is not clear if the exhaust gas analyser output can
be datalogged.

I would like to know more about the advantages of being able to close loop
Air / Fuel under acceleration. Is it done by many of the systems and what
are the advantages / disadvantages.

Hugh

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