Makes perfect sense. Even more so that its from someone that has themself trial and errored it.
Just like a non boosted A series, so it runs its best, you can dial in as much advance as you can until just before detination develops under load.

I have found too much timing equals.... ping,ping,ping. The extra work you do to motor/ supports eg, compression, chamber mods/design, intercooling, water inj, fuel octane etc allows you to run extra timing therfore usually more power without pinging or in some engines that tend not to detonate easilly, were ever timings at ie the sweet spot and either way just drops power but no pinging, giving greater safety margin. I just confused myself hope that makes some sense?

yeah the right fuel can only be right for so long, ie until you cant get it

the right chamber shape/design along with the right tune would be the thing to have

there is a pretty serious engine builder down the road from me that built a 202 head to handle 15:1 comp on pump fuel without detonation
so some time spent getting the head right goes a long way

When you are legally limited to pump fuel - this is what you tune your motor to use.

If you use the right fuel then detonation isn't an issue.

Want to trade your hectik sticker for some fully sik ones? I don't have a hectik one yet ;)

The vacuum advance thingie is there to compensate for the lack of mechanical advance at lower rpm's where there is a mostly closed throttle plate, if you mash on the gas, even at low rpm, you'll loose much of the vacuum advance too. like how the brakes don't work well if you're at WOT and trying to modulate the brakes.

Its gonna be interesting how many of these turbo A series will end up running with some of the unexperienced advice i always read being given.

The stock location on the carbie is the correct position to pick up a vacuum signal for the dissy - regardless of boxed carbie or boost referenced. During various engine opereating loads, if this position is not giving a vacuum signal - the dissy does not require it.

Now when it comes to ignition RETARD being required on boosted engines - This is bullcrap. Retarding the timing is a means of limiting boost, yes to prevent detonation. Wastegate preload tension is another way.
How does Retarding the timing reduce boost?
Well the less advanced the ignition timing is before TDC the less exhaust gas volume will be produced. Less exhaust gas volume = less exhaust gas flow through the turbine housing (exhaust side of turbo) This meaning less inlet air is compressed = reduced boost level preventing detonation.

Now if for what ever god unknown reason you can not control the detonation buy reducing boost by means of wastegate preload tension.
You regraph the dissy to limit its total mechanical advance, so then it can not advance to a degree point before TDC where detonation is developing. (Note : Ignition timing is still Advanced BTDC and is not Retarded ATDC)

From experience we (friends and I) years ago now, ran a number of blowthrough A series and one remained a stock points dissy and ignition timing was advanced to the point that it was hard for the engine to crank over to start. At times running boost levels higher than the 30psi guage could read. The engine ran on premium unleaded and it never showed audible sounds of detination during winter.

You can buy your aftermarket electronic boost retard modules if you like. Im sure you will get a hectik sticker in the packet.

With manifold vacuum, in an ideal world, you want advance, but on boost, you need RETARD to minimise or eliminate detonation. It's detonation that can destroy your engine to a degree second only to a train wreck.

And he'll remember that when he's on the side of the road with an empty gas tank

Quote:From the same place you normally get it. It works on part-throttle cruising. But don't you have to modify the advance housing to put carb input (boost) onto the back side?

Easier to simply not use a vacuum advance. It's mostly for fuel economy. You don't need it.

if you still want the vacum advance, you could try running an alternator that has a vacum pump in it. Some diesels alternators like this.