So what does it do under vacuum? advance or retard? Your description is that what ever it does with vacuum, it will do exactly the same with boost.
Whats the advantage of that?
How do you achieve in getting one to only receive vacuum and one to receive boost?
What exactly do you plan to achieve? lower emissions or performance?

Early VW rabbit automatic tranny cars and turbo audis have dual port vacuum canisters on their distributors. Many people use them when boosting their VW's.

There are heaps of car models with twin actuators on the distributors. One to advance with vacuum and one that retards with postive pressure. Porsche is one of the many cars.
But what do people expect to gain buy using it?
How do people expect to dial in the boost level at which the retard actuator reduces the degree of ignition advance?

Like I said it will be interesting to see how many of these turbo A series go. But I guess its all about ####ing up so you can learn from it. Its a shame that some will be lead in the wrong direction from the start.

My advice, leave the distributor stock, or use one of the many known elec distributors regraphed to suit a NA A series.
Dont worry about bullcrap ignition retard.
If there is detination, just back of the dissy to reduce the degree of advance. Then sort out why it was detinating. 99% of the time it will be lean fuel mixture.

Running simple non return valves in the tubes which feed each side of the diaphram is all that is needed to control an advance/retard set up. If you have the springs changed so that the retardation only kicks in once a high boost level is acheived would be best. The smartest way to circumvent detonation is by the implementation of water/alcohol injection. There are numerous ways of acheiving this. And some of the cheaper ones can be the most effective, when set up properly. I have a c32 laurel washer bottle which can pump 13psi. Through a .040 oriface, it can pump nearly a litre a minute.
I've read untold anectdotes of suprising gains atained from this method.

One way valves will not work. How is the vacuum/pressure removed from the diapham? Are there diaphrams that are easy to change springs? most are press sealed.

There are many ways to control detination. Controling it through ignition retard is only reducing performance to mask the actual problem.

So u would keep your Datto stock Steve?? Please, please tell us Mister datto master how you would improve the lineage of our loved Datto,s. Since you obviously know it all!! I,ve sat here trying to work this so I,m not nailing you, But f@#k it, Having watch you nail people on the forum I thought screw it, not me!! When I post info on the forum I,m try,n to add info to inform people of other choices to try to improve their cars, I Try not to be negative, Yes I,ve used the Escort vac advance,s and they work well, Have you used them? Probably, since you know it all.Is it my fault you don,t understand how it works, obviously.. So Peace Love an whatever other bulls@#t u preach, Have a nice day I,ll never reply to any other post of yrs!! I,ve said my bit that,s it Thanks. Bye

See thats the problem with forums like this. To many people give advice without even thinking about it. Why are you even offended for? If you have tried it/ used it/ know all about it. What is the problem? So give us all your knowledge on the subject. Its simple. What do you plan to achieve by using it?
Gee I would of thought that you could simply answer the topic on which you gave information. So why did you get offended.
My goodness I could sit back and say nothing in many of these threads. But what good is this forum if no one adds conflicting advice? Do you want this forum to be based on telling people to do things that are wrong?
I see there is a growing trend of chumps on this forum that simply cant answer simple questions on advice they have given and then therefore say oh phunk you are just singling me out. Get a life. I dont ever ask questions of people about things they havent already given advice on.

And would i keep my datto engine stock? #### yeah, many people proclaim that lots of bullshit need to be done to an A series so it can survive boost. Thats bullcrap. Ive tried and tested it and have no problem answering questions about it champ.

Use a small leak in the tube feeding the diaphrams after the non return valve.
There is a bloke in my town who recons diaphrams who is only too happy to make boost retard set ups for people.
Just beacause you disagree with a given way of doing things, doesn't mean it wont be effective. Everyone would love to have a fuel injection manifold for to use on a turbo A series. But they don't grow on trees. You make do with what you got.

Finally someone who can explain something about what they are TELLING.
So to adjust the vac/boost preload pressures you will need the actuators rebuilt.
Would you not need to know what boost pressure your engine will suffer detination before you would have the actuator rebuilt?
Champ besides the oneway valves I have never said any retard will not be effective. I have said it is not needed as one proclaims it is. There are much simpler ways to control boost levels to combat detination.
There are members who have posted in this thread that they will be setting up a vac/boost distributor setup when they turbo charge their engines. Its like they are believeing its a requirement for performance. It wont do anything of the sort. But yet none of them can give a simple answer on what they believe it will achieve. Fair enough dont reply, but I am simply explaining to the others that will read this thread for information, that retard is NOT required.
I can read some of the members posts and clearly see that they dont know jack about what they tell they have tried and tested.
This following quote since he singled me out and got all upset over a few questions, tells me he has no idea about ignition.
Quote:
Why the heck would you lock the distributor and leave the vac advance and boost retard? The boost retard is there to reduce the amount of BTDC timing while it is mechanically advanced.
So this guy believes his Zero vac timing will be enough to cause detination under boost? So how the heck does he believe he can advance it more under Vac and not have detination? Would be better off locking the distributor and running boost retard only and set the timing as far advanced as it can be without detination. But you would still need the retard actuator rebuilt so the retard is at the desired pressure. Now I dont really care what this guy does with his engine. I just used him as an example since he had a whinge about me.

Can anyone explain why Retard IS Needed on a turbocharged motor?

As to fuel injection manifold, What does that have to do with ignition and the price of chicken?

I thought I explained it ok..If ya don,t get it after that well I,m obviously talking to a brick wall so why should I keep going!! Happy now u got me to reply.. U know the guy say,s can any 1 explain why u need retard on a boosted motor.. Well leave the timing at 32 deg and put a bar of boost in, see what happens.. God wot a no brainer..How old are u mate still in kindy??Have you actually done anything in your life except shoot people down?? Any wonder I whinged at you..Whats the actuator got to do with the vaccum canister on the dist?? WTF are U talking about?? And how would you do it, come on put something usefull into this thread instead of nailing people if you can!!! Peace Love ETC BS BS BS