930 Distributor

[jcc911]

I am thinking about temporarily insatlling a 930 distributor to obtain some retard on boost while I save for a twin plug set up.

Is there any significant difference in the distributor curves througout the years?
I could possibly source one from a late 80s 930.

Also are the cap and rotors all the same, can the ones of my SC be used?

Thanks

[philip j]

Make sure you have the right rotation. Some a clock wise, some CCW.

[heliolps2]

there is two models used in the late 80's with the dual vacuum , the 1986 thru 1989 930/68 USA 9306021400 Bosch 0237302045 ,26deg ADTC and the Euro 1983 thru 1989 930/66 93060213000 Bosch 0237302034 also dual vac, 29 deg ADTC, both of them timing is set with the hoses disconnected , there also an 930 USA single vac 1978 thru 1979 set at 26 deg ADTC and a Calif 930 1978 thru 79 dual vac Distributor timing on that one is at 31deg ATDC. check the part # on the side to confirm, if you have questions about vacuum pluming let me know and I can help you with that .

Helio

[philip j]

Helio; sent you a PM. Philip

[jcc911]

Porsche # 930 602 104 00. Bosch *# 0238302045

Thanks

[heliolps2]

Cool , where did you get the porsche part # 930 602 104 00 from ?

[jcc911]

From the distributor, why?

Does any one know if this will work on my turboed SC engine???

Thanks

[cole930]

Jeremy:

Your present SC distributor can be sent out and recurved for your application or
you could get a MSD 6AL-2 Programmable and custom program your own curve.

It is in your best interest to understand you are not going to be able to run
boost levels over about 6 PSI max and hope to keep that motor together. Also
spending a fortune on a twinplug setup will not significantly change that. If you
are running SC crank, rods, pistons, and heads and you start f------ with more
boost it's going to come apart period. Boost is addictive and when you feel a
little you always want more.

Cole

[heliolps2]

Cool, that distributor is a USA 86 thru 89 turbo it will work on your SC , the timing on that should be the same as the SC, 26 deg @ ADTC @ 4000 rpm's hoses disconnected, how much boost are you running, and how do you plan on running the vacuum hoses for the advance and the boost retard ? Can you send a pic of your engine bay , so that we can what your working with.

Helio

[jcc911]

Cole thanks for the info.
Right now I am running 0.5, but have been thinking about bumping to 0.6, but am not sure.
I am still trying to figure out why my boost is coming on so late ~3800 with a K27 7200.
Ill bet that if I can get the boost to come on sooner, I will be happy and not want to increase it.

I thought that by switching to the 930 distributor as recommended by others, this may help a bit. I also wanted to keep it simple as all the electronic ignition stuff is foriegn to me.

The engine is all factory SC internals with 930 CIS and 965 IC.

[j930]

when i did my engine rebuild i had my cams reground to a SC profile, that got my boost going a lot quicker.

[jcc911]

I have SC cams as it is an SC engine.

[356911930]

Jeremy,

You may want to look into resetting the cam timing to bring your power curve down to a lowr RPM range.

Rahl

[jcc911]

Rahl,
I was actually thinking about that this AM. I have never done this before how difficult of a task is it?

[Ken911]

Yeah good luck finding one. I had to get mine rebuilt and even then i am pretty sure some of the parts used were the last ones available. What was supposed to be a couple day turnaround ended up being several weeks because no one had parts and Bosch stopped making them. You might be better off trying the msd set up.

[jcc911]

Finding a 930 distributor?
Right now I have my choice of two different ones, and just bought one of them.

For anyone interested, can PM the info of who has the one I did not buy.

[Ken911]

Originally Posted by jcc911

Finding a 930 distributor?
Right now I have my choice of two different ones, and just bought one of them.

For anyone interested, can PM the info of who has the one I did not buy.

Oh OK well thats good then i looked for one earlier this year when i was having problems with mine and there were none anywhere. Stuff like that always seems to be not available when you need it or the one you can find is way over priced.

[s5uewf]

Not to hijack, but I also have a 1988 distributor in good shape (80k miles) I'd be happy to sell. No longer need it with EFI. It's dual port.

[spuggy]

Originally Posted by jcc911

I am thinking about temporarily insatlling a 930 distributor to obtain some retard on boost while I save for a twin plug set up.

930 distributors don't provide boost retard. There's nothing magic about them.

Your existing distributor probably has the best off-idle, low-range curve to suit your motor, given that you likely won't make boost very low in the rev range - and all distributors should be all-in by 4,000 anyway.

For a RoW 930 distributor:

The mechanical advance provides RPM-related advance.
The vacuum advance provides vacuum-related advance.

Timing for most 930's is set at 4000 RPM with vacuum disconnected.

The advance imparted to the timing by the vacuum ADVANCE is bled off as the manifold pressure rises - and that advance is therefore all gone by 0 PSI relative (or 14.7 MAP - aka atmospheric).

So on a stock 930, as soon as the manifold pressure is 0 PSI (atmospheric), there is no vacuum advance left - leaving you with the timing you set at 4000 RPM (with vacuum disconnected) - which is then maintained all the way to full boost.

Some models have two hoses (early CA-only, 1986 up) - the other port messes with the timing as soon as you get off-idle, and is purely for emissions purposes at idle - once you're off-idle, it has no affect.

Again, NO 930 distributor has boost retard - unless you consider losing the vacuum advance at 0 PSI manifold to be boost retard. I don't.

If you want boost retard (or, the other side of the coin, fully-advanced ignition when not on boost, or more advanced on lower levels of boost above manifold atmospheric), you need a box that does boost retard.

MSD do one.

For pretty much the same money, the J & S Safeguard does programmable boost retard (fractions of degrees per PSI of boost above 0 manifold) - and the Safeguard also provides per-cylinder adaptive knock detection/retard in addition to any timing pulled relative to boost pressure.

The logical conclusion of running the Safeguard is that you can run more aggressive timing than stock for better low/mid-range, dial back the timing on boost to suit - and it'll also detect/warn/protect against such problems as bad fuel, clogged injector or a broken distributor that suddenly doesn't retard as it should (I can personally attest to the last).

I'm very happy with mine.

[jcc911]

Wow that's disappointing, now that I have one one the way.