My 2003 Opel Astra G OPC

The L7 is my daily driver, but for the last year I’ve been (barely) working on a project car as well. I’ve always noticed that writing up and showing off my progress with the Cuore on this forum has been strangely motivating for me. Seeing that there is a Non-Dai section on the build topic I’d like to try this with my other car as well as progress has been so damn slow.

Here’s hoping you like reading about this car as most of you seem to be from outside of Europe! To me this car is very special, rare and just beautiful. It’s an homage to Opel and what motorsport was like in the early 00s and late 90s.

The project is an Opel Astra G from 2003, specially an OPC (Opel Performance Center). It has a 2.0 turbo. It runs around 260hp and 377Nm torque.

I’ve bought this car a year ago with some problems in the hope to fix it up but money was tight as some point and It didn’t pass inspection. As I didn’t really have a place to work on it myself, I put it in the driveway and didn’t do much with it.

But then at some point the aftermarket alarm started draining the battery after half a day… Changing the battery for a new one barely fixed the issue. And not only that, the car would not start anymore and I didn’t have the code to unlock the tampering system.

But after some time I finally found a place to work on my cars and store the OPC. It’s been in the corner since December and I’ve done the following things:

  • Completely remove the alarm system. This was so hard. But after it was done she ran after 6 months on the second crank. Lucky me.
  • Replace the busted intercooler
  • Push the rad 4cm back to fit the intercooler
  • Fix cooling issues with fans
  • Some hoses and pipes were rerouted too.

But that’s about it for now. It should be driveable now. I’m thinking of taking it for a spin tomorrow, see how she drives. Change the oil and filter… Who knows, maybe some progress! Lots of problems with this car and a long way from being back on the road.


I took her out today! After about a year of not driving she’s running well.

Brakes were kinda stuck but she broke free easily. Drove a few careful round around the block as the oil is pretty old. She sounds good!

Time to finish up some other stuff and get her on the road.


A few days before inspection my xenon units died completely on both sides. Wierd, but when I looked at the cable loom to fix it I saw hell.
One of the previous owners had fit Devil Eyes but wanted to keep running xenon. These aftermarket units did not have the (kinda rare) xenon connector. The way he fixed that was by running AliExpress HIDs and bulbs. Improperly mounted and wired. So one of the first things I did back then it revert everything to the stock connectors.

Today was the day I finally assembled a pair of working headlights from lots and lots of parts. 7 sets of headlights were combined to make this work. Parts for these are very hard to find. If anything breaks, I’m gonna be in trouble again. So I’m going to try to find some old sets and source those parts. And yes, some parts are available new, but building one headlight will cost about 500 Euros.

Especially the plastic rings on the top right seem to be hard to find. They lock the igniter in place so they are very important. Once they break you can’t twist them tight and the light pattern will be off which will automatically fail inspection.

Recently a listing on Ebay came up for 75eur per ring. Which is just insane for a piece of plastic. Sadly all of them are actually broken. But two of them aren’t so broken as you can’t use them anymore. So I obviously got lucky, for now. I’m looking into finding or making an STL so I can print these forever. I can imagine when I twist them back out once a xenon bulb burns out it’s gonna fall apart again.

So with the best igniters, rings and ballasts built into the best looking shark eyes: time for a test run.

It all worked out and I couldn’t be more happy!

Xenon looks nice but goddamn is it unnecessarily difficult and expensive. If it weren’t part of the OPC package I’d probably never even have tried building it back in.


Well done and yeh getting the stl or designing the stl will save you heaps. maybe even sell some too?

1 Like

I have 0 experience with it but I’ll give it a go :slight_smile:


Well done for having that attitude. I never know how to do many things and then just jump in and see how I go. For me its the only way to learn :).


Xenon shenanigans

Some more xenon stuff! I drove to Germany to pick up another set of xenon units, they were not in good condition visually at all. But the seller said the rings and starters were replaced 2 years ago. So I got my hopes up and went for it.

WORTH IT. Two seemingly brand new closing rings. The plan now is to get these 3D scanned. Hoping the scanner can pick up enough detail to print them later.

Anyways, I also reused the rubbers from that set after a good scrub.

Side project

Then a friend and I got completely side-tracked on the car. My neighbour is doing a Z20LET swap in his Astra but still requires part of the cable loom. This part includes one of the two ECU connectors. The car has been on jackstands for half a year because this cable loom is missing. We got a hold of this loom but the ECU connector was cut off.

So, knowing these connectors are the same on the 1.8, we decided to reuse that one. But obviously the pinout is completely different. It’s German. Some wires were plug and play. But a lot of the wires had the same colours. So we decided to take apart a bit too much of my Astra and measure everything pin for pin. Making sure we labeled everything right.

Small things

At the time my Astra is back in working order so all good. A few other things I did recently:

Replaced the exit tubing of the intercooler for 1 solid piece. Just have to colour match some parts at some point. All boost leaks taken care off now :smiley:

Replaced the retour coolant hoses from the EGR and turbo as they were swollen and ugly.

Replaced the factory bumper bracket as it was in bad shape and the bumper didn’t mount anymore.

New bumper

Also a new bumper came in as the mounting points of the old one are in the same shape as the bumper brackets. Also a cutout was made by the previous owner to fit intercooler hoses which was not necessary. So now one fog lights can’t be mounted. This should fix those issues.

Steady progress!