1.8L (European Vauxhall/Opel )Ecotec engine Aftermarket support research.

[SuperS13]

So I wanted to share my research for 1.8L European engine performance parts. Here are the Engine variants that work for our 1.8L sonic/cruzes:
A18XER (ASTRA H)
A18LET(TURBO) (VECTRA B)
C18XE (CORSA)
X18XE (MIGENUM)
X18XER (ASTRA H)
Z18XER (ZAFIRA)
Z18LET/Z20LET (TURBO) (ASTRA VXR)

The x18xe/X18XER/Z18XER is the best that works closest to our Sonics engine code wise. My contact at dblias said these engines codes would work best with our sonic 1.8L

Here are the euro websites that support the 1.8L ecotec engine:
www.larkspeed.com
www.laurent-motors.com
www.dbilas.com/en
www.upg-shop.com
www.kentcams.com

This what I have so far. Both laurentmotors and dblias offer direct bolt on turbo kits for the 1.8L. Cheapest kit is a stage 1 t28 style turbo kit that good for +70hp, I reckon around 4-4.5psi boost before rods exit the block. Larkspeed offers forged pistons and con rods direct drop in cams. Dblias offers bolt on intake manifolds, etc. Upg is just a general performance shop. Anything past the down pipe or header wont work due to different chassis design. Some parts of suspension may work. Hope this helps.

 

[SuperS13]

Sorry main site links were screwy
Piper Cam Kit (Exchange) - KBZ18270H Fast Road KBZ18270H | Larkspeed
https://www.larkspeed.com/piper-cam-kit-exchange-kbz18270h-fast-road-815694/
Intake manifold for Opel /Vauxhall 1,8 - 2,0 - 2,2 16V Ecotec | 01.020.070
https://www.dbilas.com/en/Intake-tr...fold-for-Opel/Vauxhall-1-8-2-0-2-2-16V-Ecotec
Flowtec manifold for Vauxhall / Opel Astra H, Zafira B, Vectra C 1,8 16V 103kW Z18XER | mit MAP Sensor | 01.020.140MAP
https://www.dbilas.com/en/Flowtec-m...B-Vectra-C-1-8-16V-103kW-Z18XER/01.020.140MAP
Turbocharger system light Edition for Opel / Vauxhall Astra H, Signum, Vectra C, Zafira B 1,8 16V Z18XER | 10.180.002l
https://www.dbilas.com/en/Manufactu...tra-H-Signum-Vectra-C-Zafira-B-1-8-16V-Z18XER
Pistons, Conrods & bearigs Set Opel Z18XE, Saab 9-3 Bj. 2004-2009 | Turbo | 01.200.018TP Turbo
https://www.dbilas.com/en/Pistons-C...8XE-Saab-9-3-Bj.-2004-2009/01.200.018TP-Turbo
Opel/Vauxhall 1,8 - 2,2 16V DOHC (Ecotec) /Performance camshaft (also X20XER) | 14.053.002
https://www.dbilas.com/en/Engine-Va...-DOHC-Ecotec/Performance-camshaft-also-X20XER
Turbo kit OPEL 1.8L 2.0L - 8V et 16V Stage 1
https://www.laurent-motors.com/en/t...or_type_see_applications_underneath-16_valves
Turbo manifold Opel 1.8L 2.0L 16S
https://www.laurent-motors.com/en/turbo-manifold/45-manifold-turbo-opel-18l-20l-16s.html

 

[blasirl]

So I wanted to share my research for 1.8L European engine performance parts. Here are the Engine variants that work for our 1.8L sonic/cruzes:
A18XER (ASTRA H)
A18LET(TURBO) (VECTRA B)
C18XE (CORSA)
X18XE (MIGENUM)
X18XER (ASTRA H)
Z18XER (ZAFIRA)
Z18LET/Z20LET (TURBO) (ASTRA VXR)

The x18xe/X18XER/Z18XER is the best that works closest to our Sonics engine code wise. My contact at dblias said these engines codes would work best with our sonic 1.8L

Here are the euro websites that support the 1.8L ecotec engine:
www.larkspeed.com
www.laurent-motors.com
www.dbilas.com/en
www.upg-shop.com
www.kentcams.com

This what I have so far. Both laurentmotors and dblias offer direct bolt on turbo kits for the 1.8L. Cheapest kit is a stage 1 t28 style turbo kit that good for +70hp, I reckon around 4-4.5psi boost before rods exit the block. Larkspeed offers forged pistons and con rods direct drop in cams. Dblias offers bolt on intake manifolds, etc. Upg is just a general performance shop. Anything past the down pipe or header wont work due to different chassis design. Some parts of suspension may work. Hope this helps.

I reposted some of what you linked in your post as well as a link to this post ion CruzeTalk.com
https://www.cruzetalk.com/threads/1-8l-performance-parts.264525/