how much boost can stock CIS handle?

[Ameer Antar]

> > The main point though is if the engine was running anywhere out of 
> range of
> > the stock o2 sensor, running would be extremely rough, there could be
> > detonation, and emissions would be through the roof. I don't see the need
>
>Not true at all.  WOT or under boost, the system goes open loop,
>well out of the range of the standard O2 sensor.  Maybe Mr Mockry has
>put his exhaust gas analyzer on an 10V... I recall the 20V
>runs around 12:1 air/fuel under boost, well out of the range of
>the stock O2 sensor.
>
>Orin.

I agree that the o2 sensor has a limited range. Actually reading the ranges 
I've seen for o2 sensors are 12:1 to 16:1. Well in the range of WOT 
enrichment. And I don't know about 20v's, but in 5k's under boost, the ecu 
is still in closed loop mode. The only time it disregards the o2 signal is 
when hit the WOT switch. In fact I could see all of this on the gauge. Even 
at WOT, the lights were within the rich end of the display, but not 
completely pegged.

One point I'd like to make is that changing afr gauges will not let me see 
any wider range of ratios. The O2 sensor is the device that measures the 
ratio, but it doesn't not have any usable output beyond a set range. So the 
only way to see more range is to pop in a new sensor and matching gauge.

The 12:1-16:1 range seems quite adequate for my purposes. I don't need to 
know the exact ratio at every second, especially since the ecu is getting 
the same exact signal/data I'm seeing on the gauge. Sure wide-range O2 
sensors might be a great thing to have for 3 bar engines that need 11:1 
mixtures, but Audi, and just about every other car manufacturer for the 
past 2 decades, designed a system which uses an o2 sensor only covering a 
small range. Maybe there is some wisdom in this as smaller range usually 
means finer resolution...

-ameer