Legacy BE/BH Revisions — What Changed Between Rev A, B, C and D

Legacy BE/BH Revisions — What Changed Between Rev A, B, C and D

If you own a BE or BH Legacy twin-turbo (B4 GT-B, GTB etc.), you’ll come across references to Rev A, B, C and D. These “revisions” affect engine details, ECU/MAF plumbing, chassis/hard-points and even body panels. Understanding them helps with swaps, tuning and compatibility.

 

Rev A (Early BE/BH)

  • Produced around early 1998 onwards (e.g., “98-99” era).
  • Engine: phase 1 twin-turbo EJ20 (early spec) with approx 8.5:1 compression in some cases.
  • Identified on VIN plate with suffix type A or similar.
  • Mechanical layout: older MAF/ECU setup, earlier plumbing, fewer chassis reinforcements.

Key takeaway: Considered “original” spec. Swapping into later models may raise mapping and ECU issues due to component differences.

 

Rev B & Rev C (Mid-Production)

  • Rev B – roughly late 1998 to early 2000. Rev C – roughly 2000-2001.
  • Introduction of E-tune (Subaru’s factory performance calibration) from Rev B onward.
  • Engines used similar bottom-ends across B & C. Compression in Rev C bumped to ~9.0:1 compared with earlier ~8.5:1.
  • Mechanical compatibility is good: many users report Rev A-C engines can swap with minimal adaptation (assuming mapping sorted).

Key takeaway: If you’ve Rev C, you’re in the “safe middle zone” for parts compatibility. Good for turbo swaps, ABS maps, tuning.

 

Rev D (Late Production Changeover)

  • Appears from ~2001-2003 in UK forums.
  • Major differences flagged by many: electronics, ECU used, MAF sensor type, chassis/hard-mount changes (e.g., aluminium bonnet).
  • One key forum user:

“Rev D has a different ECU and MAF. The body is different… bumper, lights, grille etc are all different and not compatible.”

  • While engine bottom-end is largely the same (compression and code identical to some Rev C examples), many plug-and-play parts differ.

Key takeaway: The “odd one out”. Many parts swap issues between Rev D and earlier revisions. Owners should check exact revision identification especially when sourcing engine, ECU or body panels.

 

Summary Table

Revision

Approx years

Engine/ECU highlights

Parts compatibility

Rev A

~1998-99

Early spec EJ20TT (~8.5:1)

Older MAF/ECU; swaps may require remap

Rev B

~1999-2000

E-tune starts here

Better parts pool; good compatibility

Rev C

~2000-2001

9.0:1 comp ratio; improved ECU

Best mix for tuners/swaps

Rev D

~2001-2003

New ECU/MAF/chassis bits

Compatibility dips; proceed with care

 

 

Practical Tips for Swap & Parts Buyers

  • Always check VIN plate suffix (e.g., BE5 A) and ask for revision code when buying engines/transmissions.
  • For engine swaps: aim for Rev C or D with correct OE ECU for easiest path.
  • For body/trim parts: Rev D may use different bumpers, lights, mounts old ones won’t fit.
  • For tuning: if you’re using earlier revision with older ECU, expect a remap even if bottom-end is compatible.

 

While Revisions A–C share much mechanical DNA and are fairly interchangeable (with mapping tweaks), Rev D stands apart — not just in bodywork and electrics but in the finish-line of the BE/BH twin-turbo run.
If you’re building or buying, take the time to identify which revision you’re dealing with. It’ll save you hours and dollars down the line.

 

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