Its been a long time since I did this Circa 2007 from memory,
Mine also had one or two roll pins that located the reluctor, I probably elongated the holes and re-drilled the roll pins.
I seem to recall working out the circumference of the reluctor and divided that into 360 and marked how far the rotation needed to be to achieve the 5 deg.
Robin,
Thanks for explaining this.
Robin …
As you can see below my reluctor wheel is attached by 4 bolts, no roll pins. I have an '89 so perhaps this was changed in later models.
Once again I’m wondering what advantage I gain by a 5 deg advancement and how happy the ECU is going to be about this. I’m all for better performance but I’ve owned my XJ40 for 30 years and have always used regular gas (USA) with absolutely no ill effect. Will advancing the ignition change that ?
What about gas mileage ?
If all the effects are positive with no downside I’ll be all in.
Can’t help with the bolting situation but this is from the horses mouth;
Nope. The 94’s are exactly the same.
Could the advancement be achieved by drilling new mounting holes to the reluctor ring? 
The holes should be very close to the old holes, of course.
If you are talking about drilling new clearance AND tapped holes then yes that would work.
Better have a very good protractor and even better drill press to do this …and, just in case, maybe a spare reluctor ring or two? LOL
The Andy bracket is cheap, easily obtainable and easy to install, seems like a lot more work, precision measuring and worry in re positioning the mounting holes in the toothed ring to achieve the same result. Just my opinion. Also a lot easier to revert back to standard should the difference not suit you for any reason.
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Casso - my sentiments exactly.
Living in NZ and having a workshop at the time suited me to do it, its still reversible, acquiring an Andy bracket at the time was also not an option so I used my toolmaking knowledge.
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On my BMW m40 engine I have simply drilled the clearance holes larger so I could rotated the aseembly by a couple of degrees. Wouldn’t this work the same way here?
Gentleman …
While you could achieve ignition advancement by modifying the reluctor ring or by using a modified bracket here is something to consider …
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Modifying the reluctor ring would involve either enlongating the 4 bolt holes or drilling 4 new holes in the ring and drilling and taping corresponding new hole in the damper. And if you decided you weren’t happy with the modification, or got it wrong, you have to remove the damper again (because the 4 attaching bolts are on the backside) to restore the original setting.
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Talking to the Damper repair gentleman he stressed to be VERY careful with the reluctor ring because it’s irreplaceable and in his words a “Holly Grail” of a part.
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The “Andy” bracket (or one of your own making) looks to be very easy to install or remove.
Having just removed my damper I can categorically state that it was a SERIOUS pain in the butt job working in cramped quarters and requiring special tools. I DO NOT want to do that again. So in my humble opinion it’s a no brainer.
Who the hell wants to pay for premium gas anyway? My car is fast enough and my street racing days are well behind me (well sometimes …LOL)
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Dennis,
That makes sense to me. 
I didn’t need to run our most common premium (98, 100 is available but not as much as 98) the car ran well on 95
Hey Larry, the factory calls for premium fuel only and I sure don’t want to risk voiding the warranty on my ca – oh, never mind. 
Seriously, [accountant mode on 
], I drive my car about 3,000 miles per year. At 15 mpg that equates to 200 gallons of fuel per year. At the current cost per gallon delta of 50 cents that’s $100 per year, $8.34 per month, or - as the charity hawkers like to say - less than 30 cents a day. AND - the premium fuel I use is ethanol free (vs. up to 10% for ‘ragler’) which gives me a 10% bump in fuel economy, so the effective cost differential is even less than outlined herein. But to figure out the true difference would require advanced math and hey, I’m an accountant, not a statistician! 
All I know Mike, is that I see regular up here in BC Canada at (today) $1.79/litre and premium at 2 bucks …at around $110 for a tankful of regular every 2 weeks or so it chews my ass as it is, so there’s no way I’m going to be bled dry running even costlier gas. It’s all damn tax anyway.
At the risk of hijaking my own thread from removing a damper to octane rating …,
Remember that the only difference in grades of gasoline is the octane rating. And the ONLY purpose of octane is to prevent preignition. Octane does NOT improve performance or do anything else. So if you don’t experience pinging “preignition” while under YOUR normal exceleration habits you don’t need more octane in your fuel.
If I’m a car manufacturer and have to be responsible for warranty repairs of a new engine that is driven by a boy racer who loves to explore the upper RPM limits of every gear change then it makes excellent sense for me to recommend higher octane fuel for everyone. I mean they aren’t paying for it. Personally I drive my car like I own and repair it, and treat it with respect.
I’ll point back to the piece from Andy where he states that the ignition was pulled back from what the engine was comfortable with as a precaution, so by advancing the ignition to where JAGUAR tested to there should be no reason to increase the octane rating.