View Single Post
Old 12-01-2008, 08:26 PM
duxthe1 duxthe1 is offline
Registered User
Join Date: Oct 2004
Posts: 3,279
The idea behind the project is to be able to make adjsutments to the fuel mixture on the fly while in closed loop. With the lambda set to ~50% for normal unadjusted driving, the controller should be able to move the lambda up or down ~30% in 5% increments. So with a good 50% basic adjustment you could adjust the lambda to either a maximum of 80% or a minimum of 20%. I didn't see any situations where a normal engine (non forced induction)would want or be able to operate outside of those tolerances.

The controller adjusts the mixture richer by outputting an O2 sensor voltage that is leaner than it actually is, thus allowing the CIS-E to adjust it richer. The inverse is also true, if you want to adjust the mixture leaner then the controller outputs an O2 signal that is interpreted as rich allowing the CIS-E to adjust itself leaner. The CIS-E module tries to oscilate the mixture around 50%. The controller is designed to basicly allow you to select different values (other than 50%) around which it's adjustments are centered. Such that if I want to center the CIS-E around 40% then I decrease the O2 sensor's voltage by 10%. This lower O2 sensor voltage is interpreted as 10% lean, and the CIS-E will adjust it 10% richer. All the while the CIS-E thinks it's still centering around 50%

The concept behind the controller is to be able to dial in a bit more fuel at the stoplight when there is a BMW next to you, or to be able to dial the mixture leaner when you are on the highway at a nice cruise, and then be able to set it so there is no adjustment for general putzing around. All with just a turn of a knob.
90 300TE 4-M

Turbo 103, T3/T04E 50 trim
T04B cover .60 AR
Stage 3 turbine .63 AR
A2W I/C, 40 LB/HR
MS2E, 60-2 Direct Coil Control
3" Exh, AEM W/B O2
Underdrive Alt. and P/S Pulleys,
Vented Rear Discs, .034 Booster.
3.07 diffs 1st Gear Start

90 300CE 104.980
Milled & ported head, 10.3:1 compression
197 intake cam w/20 advancer
4 ignition advance
PCS TCM2000, built 722.6
600W networked suction fan
Sportline sway bars
V8 rear subframe, Quaife ATB 3.06 diff
Reply With Quote