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Remove O2 for dyno test??

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Old 03-19-2008 | 10:07 PM
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Default Remove O2 for dyno test??

I plan a dyno test in the future and would like to test the Air/Fuel mixtures at the same time.

With the 1985 911 3.2 Motronic system, can I remove the O2 sensor to put the dyno's wide-band-o2 in its place.

If so, do I leave my O2 pluged into the stock harness.

If I understand correctly my dyno runs are at full throttle and this takes the o2 out of the loope.

Also, is there any fuel presure adjustment on the injector system that can be used for small adjustments to the A/F ratio?

Thank you in advance.
Old 03-19-2008 | 10:38 PM
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Simply unplug the sensor from the harness and remove it.

The dyno folks will put a Wide Band O2 in it's place and connect it to the dyno.

At wide open throttle (WOT) the stock O2 is ignored by the DME.

Even at part throttle the car should run just fine without the O2 sensor, the sensor signal is simply used by the DME to fine tune the AFR under normal load.

The Euro cars run without the O2 sensor or it's circuitry all the time.

Second, the fuel pressure can not be adjusted in the 3.2L, unless you have a non-stock fuel pressure regulator.
Old 03-19-2008 | 11:39 PM
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Response appriciated!

To clarify, can I just let the o2 hang and not unplug it from the wireharness?

Or do I have to unplug it?

Thanks
Old 03-20-2008 | 10:59 AM
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Originally Posted by KeithC2Turto
Response appriciated!

To clarify, can I just let the o2 hang and not unplug it from the wireharness?

Or do I have to unplug it?

Thanks
Unplug it.
Old 03-20-2008 | 11:04 AM
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Also, try to find a shop that dynos 911s often and if possible find one with a DynaPack load dyno. The DynaPack attaches right to the axels, they remove your wheels and bolt directly to the wheel hub. No roller and no slipping of the wheels.

Contact DynaPack http://www.dynapackusa.com/ and ask them where they have a dyno installed in your area. They also know what type of cars are worked on at each shop that has one.

Best of luck.
Old 03-20-2008 | 01:30 PM
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Good info, thanks.




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