Randall Cowl Intake Bulkhead Adapter - image

Files (2)

Bulkhead_Adapter_2_Bolt.stl

STL

167.4 KB

Custom_Offset_Adapter.stl

STL

141.7 KB

Print plan

Exact totals not supplied

Print setup plan

Useful setup guidance without pretending STL byte size can predict filament, cost, or print time.

2 model files

Material plan

PETG / ASA

Published material guidance; still check heat, UV, load, and printer compatibility.

Starting setup

75% infill

A planning starting point only; wall count, orientation, and geometry often matter more than infill.

Final totals

Confirm in slicer

Choose the needed variant, then slice it for grams, cost, and print time.

Saved setup guidance is used for material, infill, support, and per-file recommendation text; editable numbers are planning estimates only.

Reference shelf

Recommended filament for this print

Product references matched to the published material guidance. Confirm diameter, heat resistance, colour, and printer compatibility.

Referenced item	What to verify	Price & availability
PETG filamentAmazon · Affiliate link	Amazon product page for 1.75 mm PETG; confirm colour, spool size, print temperature, seller, and delivery region.	Check price at Amazon
ASA filamentAmazon · Affiliate link	Amazon product page for 1.75 mm ASA; use an enclosure and suitable ventilation, and confirm seller and regional availability.	Check price at Amazon

Affiliate disclosure: if you buy through an eligible link, 3DPrintedCarPart may earn a commission at no extra cost to you. As an Amazon Associate I earn from qualifying purchases. Confirm product specifications, compatibility, seller terms, and vehicle safety before ordering or using anything. Amazon may redirect you to a nearby supported store; otherwise the original Amazon.com page remains available.

Unsure which one fits? Read the automotive filament guide.

Mechanical/Functional

Randall Cowl Intake Bulkhead Adapter

1 downloads179 views0 quality score

Print this part

Use the part context as a starting point, then confirm geometry-dependent values in your slicer.

Files

2 hosted model files

STL

Material start

PETG or ASA for durability in a car environment

Saved part guidance

Strength start

75% or higher for strength, adjust according to preference

Saved part guidance

Orientation / supports

verify in slicer

Exact totals

Slice for grams + time

Model geometry and final settings determine both

Vehicle exposure

Cabin/interior use; avoid high-heat zones

Open the STL, 3MF, or OBJ model in your slicer before printing. Exact grams, time, and final support placement come from the actual slice. Test-fit and heat-check the part before installing it in a vehicle.

License & use

CC BY-SA

Commercial use allowed

Attribution required

The file license permits commercial reuse, subject to any applicable attribution or share-alike terms. License status does not verify vehicle fitment, OEM rights, design patents, or safety.

Shared by

3DPrintedCarPart

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Description

This is an adapter designed to allow the fitment of a 76mm internal diameter pipe/duct (very common on almost all reputable branded or eBay cold air intake kits) to the bulkhead of a Mk1 MX-5 / Miata / Eunos Roadster for a Randall cowl-style cold air intake. (If the Mk2 shares washer bottle mounts with the Mk1, it will fit those too!) The STL included named "CUSTOM OFFSET ADAPTER" has been designed specifically to use the existing threaded holes in the bulkhead designed for the washer bottle to mount to, meaning that no extra holes need to be drilled aside from the single main hole for the intake to draw through. I have this part mounted to my RHD 1.6 with Air Conditioning, and a strut tower brace. This combination has the least room in this corner of the bay due to the Freon piping for the AC, the brace limiting vertical and horizontal freedom of the air filter, and the larger AFM associated with the 1.6 compared to the 1.8's smaller MAF. If I was able to fit it given these circumstances, any other combination or spec should be a piece of cake! The second STL, "BULKHEAD ADAPTER 2 BOLT" is a universal-style symmetrical adapter, in case you wish to fit a cold air feed elsewhere, or still have your washer bottle in the original spot for some reason. If you have any questions don't hesitate to ask and I'll be happy to help! Infill: 75% Layer Height: 0.20, or adjust to preference Material: ABS Support: No Raft: Yes.