OBWB8m · eight-channel wideband controller
Meet the OBWB8m.
A wideband sensor on every cylinder, sent straight into the ECU you already run. Here is the unit, one question at a time.
01What does it do?
Eight channels in. One line to your ECU.
Each cylinder gets its own wideband sensor. The OBWB8m reads all eight and sends them to your ECU over CAN, as the ECU’s own inputs.
02Why a sensor on every cylinder?
One sensor per cylinder, not one average.
A single wideband reads the whole bank as one number, so a lean cylinder can hide behind the others. With a sensor on each cylinder, it has nowhere to hide.
Each channel has its own light on the case. Green means the channel is active.
03Will it talk to my ECU?
It connects to the ECU you already run.
One cable leaves the round port and joins your ECU over CAN. The other port is reserved for future OberBuilt add-ons.
- Holley EFIHP · Dominator · Terminator X
- FuelTechFT450 · FT550 · FT600
Another ECU? Ask us. The list is still growing.
04Which sensors does it take?
Bosch LSU 4.9 or Walker 250-25001.
Channels 1 to 4 plug in on the left, 5 to 8 on the right. Each sensor runs on an OberBuilt harness, so the sensor wiring goes together without crimping.
The unit ships set up for the sensor type you choose.
05Where does the power go?
One power input.
The power input takes a fused feed, sized for the sensor heaters. The manual gives the wire and fuse sizes.
06Where does it mount?
Four corners, bolted down.
It mounts at the four corner points of its flange. Rubber isolators are recommended. Put it anywhere that stays within the housing’s temperature range.
07How does it all fit together?
Three parts. Nothing new to learn.
A sensor in every exhaust runner.
Each cylinder gets its own wideband sensor. The sensors plug into OberBuilt harnesses, so the sensor wiring goes together without crimping.
It arrives set up for your car.
The unit ships set up for your sensor type, your AFR units and your ECU.
One cable to your ECU.
All eight readings share one CAN connection to the ECU you already run.
08Do I need software?
No app. No software. Just a browser.
When you want to look inside, join the unit’s own Wi-Fi and open its page on a phone or laptop. There is nothing to install.
On the bench, it can also record a log straight to your laptop.
09What’s in the box?
What arrives, and what you bring.
It arrives ready for your car. The sensors and the wiring to your battery are yours to supply.
In the box
- The OBWB8m controllerSet up for your sensor type, your AFR units and your ECU before it ships.
- The sensor harnessesOberBuilt harnesses, so the sensor wiring goes together without crimping.
- The CAN power cableSupplied with every unit.
- Power terminal screws and coversFor the power input.
You bring
- Lambda sensorsBosch LSU 4.9 or Walker 250-25001, one per cylinder.
- A bung for each sensorOne per sensor, in its exhaust runner.
- A fused power feedWith ring terminals, sized for the sensor heaters. The manual has the sizes.
- Mounting hardwareRubber isolators are recommended.
10What else do people ask?
Straight answers.
Can I buy one directly from OberBuilt?
Not today. The OBWB8m is sold through dealers. Find a dealer near you.
Do I have to set it up myself?
No. It arrives set up for your sensor type, your AFR units and your ECU.
Does it need an app or software?
No. Join the unit’s own Wi-Fi and open its page in any browser, on a phone or a laptop. There is nothing to install.
Will my logs show every cylinder?
Yes. Your ECU sees eight lambda channels, and your logger records them the way it always has, beside rpm and throttle.
Does it log on its own?
Your ECU or datalogger records the channels. For bench work, the OBWB8m can also save a CSV to a laptop over Wi-Fi. It is not a replacement for your logger.
Bosch or Walker: which sensor should I use?
Either works. OberBuilt’s own guidance prefers the Walker 250-25001 for leaded and methanol fuel.
What do the lights on the case mean?
Each channel has its own light. Green means the channel is active. The manual lists every colour and what it means.
How do I update the firmware?
Your dealer handles updates for now.
Is there a warranty?
No. The OBWB8m is a racing product, and OberBuilt does not offer a warranty on it. That does not take away any rights you have under the consumer protection law where you bought it. If something goes wrong, start with the dealer who sold it; issues are handled one-on-one, case by case. How the unit is installed, wired and tuned is up to you and your tuner.
My ECU is not on the list.
Tell us which ECU you run at support@oberbuilt.ca. The list is still growing.
11What are the numbers?
The full specification.
Every number we publish, with its condition where known. No form, no email address.
| Item | Value | Conditions |
|---|---|---|
| Measurement | ||
| Channels | 8 | One wideband sensor per channel. Sensor type set per channel. |
| Sensors | Bosch LSU 4.9 Walker 250-25001 | Set up for your sensor type before it ships |
| Sensor harness | 3 ft Bosch 5 ft Walker | OberBuilt harness. About 6 ft to the sensor once the sensor’s own lead is added. |
| Lambda reading | 0.01 λ | Resolution |
| Measurement rate | 250 Hz | Internal, per channel. Not the output or log rate. |
| Output to your ECU | ||
| Protocol | CAN 2.0B | CAN-FD capable |
| Broadcast rate | 0–100 Hz | Per packet |
| Identifiers | 11- or 29-bit | Standard or long |
| Data format | Float or scaled integer | Floating point, or scaled 32-bit integer |
| CAN ports | 2 | One to your ECU. The other is reserved for future OberBuilt add-ons. |
| Connects to | Holley EFI FuelTech | Over CAN. HP · Dominator · Terminator X · FT450 · FT550 · FT600. The list is still growing. |
| Setup and logging | ||
| Configuration | Built-in web page over Wi-Fi | Any modern browser. Nothing to install. |
| Logging | CSV to a computer over Wi-Fi | For bench work. Your ECU or logger still records normally. |
| Power | ||
| Power input | 9–20 V | A fused feed, sized for the sensor heaters (see the manual) |
| Current, controller | ≈ 0.3 A | Controller only, no sensors connected, peak |
| Current, sensor heaters | 1–2 A each | Typical |
| Current, peak per sensor | 6–8 A | At sensor warm-up |
| Current, peak total | Up to about 65 A | All 8 sensors warming up at once. Size the fused feed for it (see the manual). |
| Physical | ||
| Sealing | Designed to IP64 | Dust and splash resistant by design. Not independently tested. |
| Housing | PBT-GF | Engineering polymer |
| Temperature | −20 to +105 °C | Operating range |
| Size | 122 × 38 × 178 mm | W × H × L overall, including connectors and mounting flanges |
| Mass | ≈ 440 g | |
| Mounting | 4 points | M6 or ¼-in fasteners. Rubber isolators recommended. |
Downloads
- User manualPDF · light colours, Wi-Fi setup, wiring by functionComing after launch
- FirmwareUpdates go through your dealer for nowComing after launch
12Where do I buy one?
Find a dealer.
The OBWB8m is sold through dealers: five shops across the United States.
Run a shop and want to carry it? Email support@oberbuilt.ca.
- Autotrend EFIDiamond Springs, CA
- The EFI StoreLake Havasu City, AZ
- Redline MotorsportsBloomington, IL
- Big 3 RacingWest Salem, OH
- TNT Performance AutomotiveOwego, NY
Built in Winnipeg
Designed and built by OberBuilt, Winnipeg.
Questions about a fitment or an ECU come to us at support@oberbuilt.ca.