EURO 2 pot distributor replacement

[Seppo]

We have a 1978 US Turbo car with a 1 pot ignition distributor
I have read there is some advanced to replace the ignition distributor to later EU 2 pot vac-boost retard distributor.
I have read some many different opinion?

[RarlyL8]

I do the opposite and use no vac pots at all. The Euro distributor has a more aggressive timing curve than the USA. To take it one step further a timing retard function can be added allowing an even more aggressive curve that will retard on boost to your settings.

[Seppo]

Ok I use the US Distributor.
So I can disconnect the vac pot and close the line.
How much should I set the mechanical timing, 26 degree on 4000RPM?
I have SC cam, Kokeln IC, 1 Bar spring, K27-7200, the other are stock
Thanks!

[spuggy]

Originally Posted by Seppo

Ok I use the US Distributor.
So I can disconnect the vac pot and close the line.
How much should I set the mechanical timing, 26 degree on 4000RPM?
I have SC cam, Kokeln IC, 1 Bar spring, K27-7200, the other are stock
Thanks!

34 degrees @ 4000 will work so much better off-boost that it's not even funny.

Then use boost retard to lose the extra timing.

[RarlyL8]

The one pot distributor is most likely ROW or non-CA, check the part number. If so you can add a boost retard (such as MSD) and increase the timing as suggested.

[Seppo]

i just removed and plugged the Vac pot. Set the mechanical timing to 20 degree at 4000RPM. I am happy with the result. The car pull really nicely
Only the AAV giving to mach air and the idle start at 2500RPM. Thanks RarlyL8!

[RarlyL8]

Euro spec is 26° @ 4000rpm, will give you a bit more bump. If you add a boost retard module you can increase to up to 36° @ 4k off boost and have it pulled back to 26° on boost. This is with 90 octane fuel, no heat soak.

[356911930]

Hi Brian,

Is this setup for using a locked distributor with MSD digital CDI with boost retard, replacing the Bosch CDI unit? You can't accomplish this with a ROW stock distributor and just the boost retard, can you?

Rahl

[spuggy]

Originally Posted by 356911930

Is this setup for using a locked distributor with MSD digital CDI with boost retard, replacing the Bosch CDI unit? You can't accomplish this with a ROW stock distributor and just the boost retard, can you?

J&S Safeguard "universal" model (for use with distributor and CDI, there are other models for "dumb" or "smart" coils/COPs) has built-in boost retard as well as per-cylinder knock detection/retard.

I seemed to recall I set the DIP switches to pull out 0.5 degrees of the additional timing per PSI of boost over atmo, to arrive back at factory timing at 0.8 bar. Something like that.

I never saw any knock under boost, ever, anyway, in 30,000 miles with a CIS 930/60 with slightly higher C/R, SC cams and stock wastegate. All the "real" knock detected was 2900-3200 RPM under light load (1/3 throttle climbing hills in 2nd on a 5-speed) w/ crappy West Coast gas. Any "ghost" knock (like when you lift over 6000 RPM and everything gets a bit slappy/noisy) is (a) light/faint/random and (b) pretty irrelevant - because you're off the gas, and everything shuts up as soon as you get back on it anyway.

The RoW advance curve - even with nominally exactly the same - factory - timing @ 4000 - was worse for low/mid-range knock than the US dizzy that seized the advance unit; RoW very noticeably more aggressive getting the timing in lower down.

http://forums.pelicanparts.com/911-930-turbo-super-charging-forum/611409-my-j-s-safeguard-paid-itself-last-week.html

I liked the Universal so much I bought the COP (Interceptor) model to run with Motec M800 and COP, rather than screw with Motec's knock detection (on the advice of my Motec-trained tuner/dealer, who fitted both Safeguards and the Motec). It was a lot easier to setup - and I'm just as happy with it as I was the original.