Invaluable Resources - C20LET


Motronic 2.7 System overview, engine management (LHD model).

Hey, the Ferrari F50 uses this version of Motronic, and so does the 512TR, so it can't be that bad...

Transer box section, in case the excellent Cav16 site is down

4x4 Description The mysteries explained. Please note that diagrams depict the LHD model.
What to check when buying a 4x4, as well as testing the tx box, removing the tx box, and reinstalling it again taking care not to break the fragile temp sensor.
Dos and donts and dismantling it to see the crown wheel. Changing the accumulator bulb
More descriptions of the hydraulic systems, the electrical setup and bleeding & level checking the PAS system.

LET Turbocharger Setup Differences from the XE, pipe and connection diagrams

More Motronic 2.7 Wiring diagrams, pin layouts and troublecodes

C20LET ECU loom spread out (posted by Terry81 on MIGWeb)

Whole Calibra turbo document 9Mb word doc

Terminal assignments.

Troubleshooting: Page1 Page2 Page3 Page4

How to fit a Phase kit (handy if you've got it second hand with no instructions)

Turbo Fault Diagnostic table from Turbo Dynamics

Some interesting tech FAQs from CavWeb (register first)

Turbo clutch change by M Clayton (not many pics, I'm sure the description of the procedure will discourage several DIYers!). If the link is dead (hey, this is the internet!) here's another copy

Gearbox reconditioning article. See what's in that box!

Alignment specifications for the Calibra 4x4

Vauxhall V6 engine manual 22Mb PDF (relevant perhaps to some)

Vaux (well, Holden!) Monaro manual 3.2Mb PDF

Guide for an LET conversion of a MK2 Astra (local copy here)

SAE Aerodynamics: brief extract from an interesting SAE document regarding vehicle aerodynamics


AutoCar Test for the Calibra Turbo:
Fast Lane Test for the Calibra Turbo
Car Design And Technology test
Interview with Dr Fritz Indra, father of both the C20LET and the XE

Calibra Product Guide

Excellent 24-page confidential brochure. It was aimed at dealers and fleet operators. Contains comparisons with the main competitors.

(4.5Mb PDF)

Calibra turbo original brochure (3.5mb PDF)

courtesy of ClubCalibra.net

If the link doesn't work, try here

Calibra official sales brochure

(6.5Mb PDF)

Calibra 1990 introductory 25-page full brochure

(4.9Mb PDF)

Cliff Calibra brochure (German special edition)

(1Mb PDF)

Unveiling of the Calibra turbo at Silverstone

(2.3Mb PDF)

Calibra 95 update brochure

(1.5Mb PDF)

Calibra DTM brochure

(1Mb PDF)

4-page magazine test of this South-african LET factory variant.

Light and nimble, shame Europe was left out

(700K PDF)

Yet another 4-page test, carefully restored from washed-out originals

(1 Mb PDF)

Original brochure of the first Cavalier 4x4

(1.5Mb PDF)

Courtenay 4x4 V6, supposedly a one-off

(1.7Mb PDF)

Calibra 97 Model lineup

Only includes 16v weakotec and V6 though, the mighty turbo has been dropped.

(5.5Mb PDF)

Calibra Rosberg (special edition turbos and V6s). Standard engines and clother interiors though, I wonder why he bothered...

(1.6Mb PDF)

EcoTec Racing engine handbook

(NHRA's Summit Sport Sompact Drag Racing Series)

Excellent, interesting and very rare scans from the GM original, thanks to a dedicated fellow enthusiast.

(4.4Mb PDF)

Turbo Sizing article

Scans from the American Sport Compact magazine - sister publication of Turbo and High Performance, a subscription to which I feel is worthy

(1.4Mb PDF)

Which? magazine article on speed cameras in the UK

(500K PDF)

Very interesting technical article on the WRC scoobie. Secrets about water injection, running silly boost etc...

(1.3Mb PDF)

Biturbo with 11:1 compression and running lean. The future?

(200K PDF)

EVO buyers guide - not 100% relevant here, but interesting anyway

(7Mb PDF)

Pulp Friction: how brakes work (2Mb PDF)
Skyline R32GTR manual (24mb PDF)  



The guides below (page scans within Word documents) are based on original scans by Ahmed Bahgat, a tireless ClubCalibra member from Sydney, Australia:


Air Conditioning


Engine Block

Checking & Adjusting Procedures

Check & Control: Electrical Equipment and Instruments

Cooling System

Crankshaft Disassembly

Cylinder Head Disassembly

Rear Axle & Rear Wheel Suspension

Fuelling & Exhaust


General Info/Tech Data


Motronic 2.7

Oil Circuit

Rear Differential

Rear Suspension

Seats & Inner Trim Panels

Engine Timing Side

Turbocharger Disassembly

Transfer Box

Wiring Harness & FuseBox


End of the line ________________________________

pic by MartG from MIG


who would dare outrun this?


...maybe this one, but only off-road



Calibra pickup?

Wait, it gets worse....


Very ZZ Top.

Yes, this is a Calibra, I kid you not!

This one has seen better days, but more pain is in the horizon...



Where were they made anyway?

Starting from November 1995, all Calibra production was switched to Saab-Valmet assembly plant at Uusikaupunki, Finnland. Some say these last finnish ones are the best made of the lot. Uusikaupunki is currently assembling Porsche Boxters.

Look at your VIN number:

WOL 0000 85 [K to V] [1 or 9] XXXXXX

If '1' it was made at Ruesselsheim

If '9' it was made at Uusikaupunki