Crimson Racing Wiki

MAP Sensor Bung

Subteam: PowertrainSubsystem: ManifoldsAssembly: Intake AssemblyCars: CR22, CR25, CR26I

Purpose

Provides the port for the manifold absolute pressure sensor in the plenum.

Function

The MAP sensor is a single point of failure that results in engine shutdown, which is why an alpha-n table estimates manifold pressure from throttle position and engine speed as a fallback.

Design Process

No part-specific design process is documented. The Manifolds subsystem design process applies: 1. Build the engine model in GT Suite from measured geometry: silicone-cast and 3D-scanned intake ports, dial-indicator-measured cam lobe profiles, MTS-measured valve spring curves. 2. Use GEM3D to convert manifold CAD into GT Suite flow geometry, which cut manifold setup from several hours to about 30 minutes and let subassemblies be swapped for fast comparison. 3. Sweep plenum volume, runner length and primary length in the model against volumetric efficiency. 4. Confirm on the flow bench. CR26I plenum flowed 2.34% more than CR25 and 11.15% more than CR22 on average across 10-50 in-H2O, with testing extended to 70 in-H2O (17.4 kPa) to reach WOT conditions. 5. Prototype-test the muffler on the previous car before finalising, sweeping length (14 in and 16 in), packing density, tailpipe diameter (2 in and 1.5 in) and a diffuser-style tip against the sound limits.

Manufacturing Process

Purchased.

Full Material List

Aluminium, welded or bonded into the plenum. From the cost report drawings and CAD: From the cost report drawings: 6061 Aluminum (MAP Sensor Bung).

Reoccuring issues

None recorded. This part has no entry in Knowledge_Transfer/Issue Logging/Fault Vault.xlsx, in either Issue Log.xlsx, in CR22/Issue Tracking/Shakedown 7-15-23.xlsx, or in any design review issue list found in CrimsonStorage or Box.

Properties

Dimensions called out on the cost report drawings. These are the figures printed on the drawing, not a labelled specification; open the drawing itself for what each one refers to. MAP Sensor Bung (as drawn): 17.271.73, 12.34, 1.23, 4.83, 0.48, 9.53, 0.95, 46.58, 4.66, 30.35 Source: Cost report drawings: CR25/Powertrain/Design/Y - Cost Report Drawings/Manifolds/Intake/MAP Sensor Bung.pdf; CR26i/Powertrain - IC/Design/Y - Cost Report Drawings/Manifolds/Intake/MAP Sensor Bung.pdf; CR27i/.Powertrain/Design/Y - Cost Report Drawings/Manifolds/Intake/Archive/MAP Sensor Bung.pdf Quantity per car, as costed: 1

Still to document

Nothing in CrimsonStorage covers these yet.