DIYEFI.org Forum

Looks like AEM has followed suit, after PLX, and, updated their 30-4100 ( now 30-4110 ) AFR gauge to use the LSU4.9 sensor. Seems to be a lot of that going around.

It's probably more of a "carb thing". But 2000-2500rpm will usually get you through idle and transition, and on to the main circuit. Which is about all you need (mostly). If you are looking to detect high speed misfiles, then, even a NB may no be fast enough. High-speed distribution, we al...

I am quite convinced that regardless of controller design the bosch lambda sensor is not capable of resolving individual cylinder AFR at the collector, that is the holy grail. With that out of reach, resolving response time further is of no tangible benefit. I have personally done this. Specificall...

The current Bosch LSU4.2 is fast enough. The LSU4.9 is slightly slower, due to its sealed design, IIRC. It's the interface circuits that slow them down. I am pretty sure that I could drive one to about 1kHz ( 1000 samples/sec ) with the right design.

jharvey, An interesting use of near-instantaneous AFR response time is... If one knows the exact AFR, on at least, a per revolution basis, couldn't one just use that signal to directly control the injector timings ? i.e. set a target AFR table for specific rpm/load conditions and use a straight soft...

Thanks Fred. That makes a lot more sense :) I know the guys want to make a splash for their new product. But, they need to realize that almost ALL of the existing wide-band controllers out there already use the Bosch CJ1xx chips :) If you really want to compete with the speed of the Innovate control...

Remember that that 50ms only gets you 63% of the way to the correct value, from where you started. To get 90% of the way takes ~120ms and 95% ~150ms etc. The trick is not so much to read individual cylinder data, although that can be extremely useful. It is that you get data that actually correlates...

Also... if you look at that wide-band shoot out article ( ALM was not there ). You will see that all of the units that use the CJ125 ( or its kin ) scored 300ms or slower in the latency tests. And... only 1 scored an accuracy of 0.10 AFR point or better.

I can't quote the document directly, due to NDA. But, if you look at the traces in the picture, you will see that the scope is set to 20ms/div ( minor div ). The ALM output takes about 3 divisions ( 60ms) to climb to about 63% of the value that it eventually settles on. This is not a coincidence :) ...

Gotta call BS on this one. Anyone who knows how the LC-1 works internally, knows exactly how those traces were made. The ALM sensor was in a bung near the engine. And, the LC-1 sensor was at the end of the exhaust system, probably stuck in the tailpipe. Thus delaying its readings by the length of th...