non locked distributor on turbo motor

[theKbStockpiler]

I would like to know what makes it impossible to use a mechanical/vacuum distributor ,limit the mechanical advance and make the vacuum part disengage when the turbo is creating boost?

Thanks for your experience and expertise!

[V8Nate]

I would like to know what makes it impossible to use a mechanical/vacuum distributor ,limit the mechanical advance and make the vacuum part disengage when the turbo is creating boost?

Thanks for your experience and expertise!

I'm not sure about that last part but you can totally use a svda or dvda distributor with boost. I have not personally used the dvda in a boosted application but I have heard that you can use one nipple from the adv. Can for boost retard. I have on the other hand used a svda with a vacuum advance canister from a turbo saab, it bolts right on the distributor. If I remember correctly it will pull 5 deg. Of timing once you are over 3 lbs. As far as limiting the mechanical advance that is as easy as bending the stop tab in the dizzy or drilling and tapping the stop tab and putting a grub screw in it. It is definitely a mechanical way of doing things and it will work( much better than just limiting your timing or completely locking out your dizzy)

Hope that answers your questions:)

[GARRICK.CLARK]

I do it this way.
lock the distributor.
Set timing at 24 at idle.
Use a dual vac can.
Blow boost into the front nipple on the can to retard the timing from 24 back.
I've tried all combos of timing, limited/unlimited etc.
This is what works for me.

[carsten bb]

Hi.
I have been visiting this forum for almost 20 years now... and I hoped that nobody would recommend locking it at 24 degrees anymore.....

When your engine runs off boost, it would like a normal advance curve. No limiting! Maybe 32-34* Mechanically , and maybe up to 40* at light cruising vacuum advance.
Under boost you would like it to retard. 1 degree pr 1 psi is a nice rule.

Here is a link to how I did it some 18 years ago:

viewtopic.php?f=3&t=9678&p=66796&hilit=Carsten#p66796

Best regards

Carsten

[theKbStockpiler]

Thank you for the great link. That will keep me busy for a while.

[buguy]

Screw all that.
www.cbperformance.com/CB-s-Black-Box-Pr ... p/2013.htm

[carsten bb]

Screw all that.
www.cbperformance.com/CB-s-Black-Box-Pr ... p/2013.htm

Screw that.
http://www.maxxecu.com

If you really want to do it right.

[petew]

I'm with Carsten, although I'd suggest MS2 setup spark only. Throw your dizzy away and put a crank trigger on. That would allow you to datalog as well as spark control. Then when you're sick of rejetting, install some injectors and go EFI.

[buguy]

Hard to beat the support of MS.

[Krochus]

I’ve done, full advance with a MSD retard box. Various forms of vacuum and finally Megajolt.

Far and away the best performing distributor based ignition setup I ran was an 009 limited to 10 degrees advance total.

This made for a nice easy to start 14 degree idle and a boost friendly 24 total.

Honestly limiting an 009 is easier than locking one. I don’t know why you’d do that..

The problem I discovered with any system that waited for boost to retard the timing is that retarding the timing FIRST makes the turbo come on and build boost way harder. So if you wait for boost your adding unnecessary turbo lag and complexity for no good reason.

[buguy]

How did you get 24 degrees if you limited it to 10?

[theKbStockpiler]

He meant the total advance range was 10 added to 14 for a maximum of 24.

[buguy]

Oh. Got it!

[GARRICK.CLARK]

I can understand that its not the best way to go ,but its the only way my motor will run without it pinging.
I am looking into MS, Its just a little complicated for me at the minute.

[Krochus]

Have you considered water meth injection?

Megajolt is a wasted spark ignition based on the Ford EDIS from the 90’s. It’s a lot cheaper and user friendly than megasquirt for ignition only