The Astra Red top will be a C20XE 2.0 16v 150bhp, I brilliant engine they make shed loads of avg torque across the whole rev range. I have one running 300bhp+ with a nice T3 turbo bolted to it with 4x4 transmission is a Calibra
Standard 150bhp mapping on a AGU is too "bland" to keep up the the C20XE engine which will offer the power lower down in the rev range, so with every gear change the Astra will pull away from your AGU. But come Sunday all being well you will be flicking stones up in to his path behind you watching his car get smaller and smaller each time you change gear.
Saying that my old 1992 Calibra SE2 2.0 16 non turbo with an old R-tech stage2 chip running 168bhp, beat a Bentley Continental on a Toll road 6am one morning 3 years back upto 160mph I beat him..... only because he had an 155mph speed limiter..
you should have seen the guys face I was
pis***g laughing my head off once I had realised what had gone on with his car.
Drunk Nick!