Thanks for asking.

I posted a diagram in another thread:
http://forums.pelicanparts.com/4998326-post24.html

PatKeefe is in the process of installing one.

Certainly John you're more an entrepreneur than a peddler. To do the research, do the R&D, and come up with a marketable product is no easy task. In my opinion there is a place for your knock controller on our 930's, but for me it just has to take a number, stand in line, and wait its turn. A few more success stories - specific to the 930 - would be beneficial of course.

I think you also posted one for hookup to the MSD6AL, if I recall.

Mark:

Bob Boyer at Random EMS in Seattle has installed several on aircooled Porsche, usually in conjunction with a Wolf ECU.

He would be glad to talk to you about it.

For MSD, connect J&S Blue mag pickup output wire to MSD mag pickup input, Violet wire.

Or, you could use the J&S "Tach Out" (labeled Aux wire on pin 3) to trigger the MSD White wire.

Gentlemen & Mark,
I took my distributor to an old friend and had him put it on his old Sun Machine. We now know what the 930 timing curve really looks like:

Crankshaft Degrees

Vacuum is retarded 10* at idle

1460 RPM 2*= 12* WVA

2260 RPM 6*= 16* WVA

3000 RPM 9*= 19* WVA

3600 RPM 12*= 22* WVA

4000 RPM 16*= 26* WVA


These numbers were noted by me while watching Mike spin it. We spun it multiple times to confirm our original figures repeated.

This was a single pot 80 ROW 930 distributor

The only difference between these numbers and the dual pot should be the difference, if any, in vacuum advance/retard of the dual pots.

If the engine has ; large cooler, free flow exhaust, and smog removed that should negate any appreciable difference between the ROW and the USA spec engine and these specs should be applicable too both.

I did this because I will be adding my new MSB 6AL-2 soon and I needed to know where to start building a timing curve. If using a new MSD 6AL-2 this even works better because you are locking out the distributor. That means you will remove the vacuum pot / pots, strip the centrifugal advance weights and springs, pin the advance plate (if required), and lock down the distributor at max advance. Therefor you will be programing all the timing. Hope you find this helpful.


Cole

Since you're going MSD, you might as well go all out and get their knock detector.

Jegs has it for about $246:
MSD Ignition 8964 MSD Engine Knock Alert

Cole,

Great work.

---------

Knock Sensors are good idea which is probably why Porsche did it with the C2's and later motors.

However Porsche is said to have made some changes in order to 1) reduce the motor noise for less interferance, and 2) create an effective place to mount them.

I understand they re-engineered the chain ramp and tensioner to quiet them down as an accommodation.

They modified the cylinders to create a place to mount a bridge so there was an effective place to mount the sensor.

If this is not done one would have to guess the sensitivity of the knock sensor might need to be questioned. If not timing might be pulled back when not necessary or the sensitivity might have to be reduced to the point that could reduce protection and give a false sense of security.

If someone is intent on adding knock protection on non 3.6 cars I believe LN Engineering can make cylinders with mounting bosses on them to solve that issue. As to managing the chain noise I do not know if the 3.6 ramps and tensioner can be retro fitted to a 3.3.

An air cooled motor is a lot noisier than a solid block water cooled motor which is probably where an aftermarket knock system might best shine.

If I was running a 944T I would consider such a set up but I am not sure about its effectiveness for an air cooled 930 without the proper modifications to support it as deemed proper by Porsche.

I have not studied this topic much so I could be in error.

Here's a turbocharged Beetle with one, showing where he mounted the sensor:
Shoptalkforums.com • View topic - MSII with knock sense- where to mount the knock sensor??

Aren't VW's noisier than Porsches?

american-pi.com has been selling them to the Corvair market since '95. They must have sold close to a hundred.

Do 911's have the same timing chain ramp?

Our first installation for a magazine was on a 911, owned by Rick Hearn. He was an engineer at Calcomp in Anaheim in 1991, and had reverse engineered his Motronic ECU. He raced it on the weekend with a chip that had a little more timing and a little less fuel. I don't have the specs, as wideband A/F gauges weren't available then. I think he said it had two more degrees timing.

Greg Brown did the install, and I forgot to ask where he mounted the sensor. Since it was aircooled, I was a little apprehensive about engine noise, but that was quickly laid to rest when I connected my 'scope to an internal test point, which shows the processed knock signal.

We drove around a bit with the scope on my lap, to demonstrate it detected without falsing, then turned it over to the owner. He drove away with the race chip in it.

James Sly did a small writeup on it in European Car or VW and Porsche, I forget which, but I lost my copy.

About three years later, James Sly told me that Greg Brown went through Rick's engine to freshen it up, and his comment was there was no way it would have lived with that chip without the knock controller.

Gentlemen & Mr. Gimpy,

I have been cramming my chemo poisoned brain for the last couple days in anticipation of the new arrival Mon. or Tues., the MSD 6AL-2. I will tell you, either my old age is catching up with me or chemo killed more brain cells than I thought because this isn't as easy as it used to be.

Tried to research all I could from creditable sources so I don't lay out any definative statements here that have a lot of holes in them.

First I was wresteling with the thread Mark and Keith had about rotor phase shift and have concluded it is a non issue. There is no advantage running more total advance than 29*- 30*. And if you look at the numbers a 20* phase shift at the crank is 10* at the distributor which is minimal and you can always reindex the reluctor plate to compensate for any difference if you wanted added total timing.

And while were here, an interesting tid bit came to light in my reading, it's not pertinant to my application but is kinda cool. If our vacumme advance is 8*-10* and we replaced it with a dual canister advance/ retard canister you could replumb the advance port from the throttle body to the manifold, leave the retard port open to atmosphere, and it would automaticly retard timing 8*- 10* at the onset of boost. Cool Hugh !!!!!

In researching the vacumm advance I realized MAYBE it should remain and we should just remove the centrifugal advance weights and springs. The vacuum advance is there to provide some advance for very little & no load conditions and when there is not enough load or rpm to activate centrifigual advance. Vacuum advance provides smoother street driving and helps emmisons. It has no effect when under load, WOT, or boost. The jury is still out on this one. More to come.....

So what that leaves us with is, and keep in mind here I'm trying to figure out my 6AL-2 timing curve, is initial timing, centrifigual timing and total timing. The knowns are: 10*vacuum advance off idel, 0*- 2*inital,16*centrifugal, and 29*-
30* total. All advance needs to be in by 2800-3000 RPM and I want to be at 18* -20*at 1 Bar of boost.

From what data I've gathered I want to run 10*- 12*Initial timing and I have 16* more centrifugal by 2800 RPM and I'll set the Total static at 29*. From this point it should be relative easy to punch in 10*-12* of retard on boost, look at what the LM-1 and the MSD MAP have to say and tweek from there.

THEN TAKE HER OUT AND RIDE HER LIKE THE SLUT SHE IS !!!!

Feed back Please !!!!

Cole

Ol' Cole, you gotta stay away from that airplane glue. It'll fry your brain.

I read through all this, and everytime I read it or some other post regarding timing I end up with more questions yet. Anyway, see my comments in living color below:

Mr. Mark,

Thanks for the reply and critique. I think this is importand because we are getting down to the Holey Grail (a real 930 tiiming curve)

I stand corrected on the advance plate pinning. If you removed both the springs/ weights and the vacuume advance you want to pin the plate. If you leave the vacumme advance you would not pin the plate. The only cases you pin the plate anyway is to keep it from vibrating and wearing the distributor shaft if it's not being used. I haven't pulled the distributor apart yet so how it's integrated into the distributor mechanics is unclear at this point..

I understand what your saying about the dual canister on later 930's and luckally this information was not in direct reference to a 930. We do not really know, at least I have seen no difinative proof, how the 930 dual canister really works. All I am saying is Bosch made a dual advance / retard canister for VW's that will work. The advance side canister works as usual, the retard side canister is not connected to anything which allows the advance canaster to breath. The key here is where you connect the advance canister, you move it from throttle body vacuum to manifold vacumme which allows the boost pressure to negate the advance vacuume.

The timing advance produced by the vacumme advance is never figured into total timing. Hence, why you remove and plug the vacumme advance line when you set inital / idle timing. You leave the line connected when you set total timing at 4000 RPM because there is little or no vacumme at that speed.

Theoretically the curve is going to be 10*- 12* inital timing add 16*-18* between on throttle and 2800- 3000 RPM ( I would start by programming it in at 1* pr. 100 RPM from 1000 RPM to 2800 RPM), have your total advance at 4000RPM set at 26*- 29* Then once you can look at your MAP feed back for manifold pressure you going to plot your retard map based on manifold pressure/ RPM. Knowing that with 7:1 compression your relativly safe at lower boost levels. Your danger of detonation areas are going to be at the points of highest manifold pressure. We know our torque curve is pretty liniar and that curve is following manifold pressure. Now pull timing by 10*- 12* based on those highest manifold pressure points.

I think I' pretty close here but I am always open to constructive critisum. I'm trying to do this in a logical progression that creates the safest learning condition.

I am going to add a disclaimer here on the vacuume advance issue. There are so many varying opinions on this that I think it needs to be researched further. Any input here would be apprecited. I think will try it both ways. Run with the vacuume advance hooked up, then pull and plug the line and try again.

Cole

OK Cole, I think you've got it figured out. When you tear into your distributor, please do a photo shoot. I could probably figure it out once I got into it, but all those internal mechanics have to be figured out (springs, weights, and pinning). I always figured on disabling all vacuum lines (whether they act as vacuum-driven retard at idle, or boost pressure retard, or whatever the heck they do), and locking down the mechanical advance to where the only timing to be had would be completely dependent on the electronic gizzmo programming.

Did you also need to purchase and install a MAP sensor to go with your 6AL-2? I think the anwer is yes, just confirming. I need to download the installation manual and programming software to get more familiar.

Exciting stuff. I think what I would do would be to initially program the unit to very closely approximate what we think we know about the stock timing curve. Do this to verify that the car runs "normal", then move on to progressive programming - as you've described - to get the additional advance we're after. I like the fact that you're planning on puting all the timing in by 2800-3000 rpm, vs. the stock dizzy curve of having it all in at 4000. As to the slope (1* per each 100 rpm) that's probably safe.

Thanks for keeping us in the loop as you break new ground.

if it's any help to the CIS guys i'll tell you what i've found that makes my engine most responsive.... TONS of timing. My idle timing is 28* and within 1000rpm over idle the timing is all in at 38*. I've tried a slow ramp in timing as rpm climbs but for stomping the throttle from a rolling idle in 1st gear nothing beats alot of timing. Now granted I can pull the timing under every condition with EFI but these low compression engines seem to love lots of timing (before the onset of boost) so don't be afraid to advance - advance - advance

BTW
Happy Holidays

Mark,

I bought a GM 3 bar MAP a year or so ago on EvilBay with the connector for $20.00. I got a 3 bar because I'm tying it into the LM-1 and it is actually reading from a 1 bar starting point because of atmosphere and then reads boost from there on up. That way if it happens to go over 1 bar of boost it will still display rather than max out at 2 bar which would be 1bar of atmosphere and 1bar of boost. Also if you use a 3bar you can program it in to read neg. numbers for Atmosphere (vacuum) and then go Pos. for 2bar of boost readings.

The GM MAP sensors are supposed to be the best you can get and are compatible with nearly any application out there, They do require a 5vdc input/output and there isn't 5 vdc to be found on our cars. I built a 5 vdc power supply from Radio Shack parts for about $5.00 total works great. It
converts 12vdc to 5vdc and I added a couple caps so you get a nice clean output signal. If you need the info. let me know.

Still kicking around the vacuum advance question, it has a real contribution of extra advance at idle, cruise, and light load but at WOT and boost it is nill. This would give you the extra timing during the typical lean driving conditions, more low end throttle response, and a total of around 40* at cruise. Trying to find if there is any downside. HELP !!!!!


DR,

I think the EFI and EDIS-6 are everything one could want to make these old sleds go but I'm still stuck on doing it with CIS. Old Farts get hung up on old technology I guess and then there's the dollars involved. Couldn't agree more with tons of timing to get her off her ass but then CIS wants to go lean, you can't change timing on the fly and that limits you too. Trying to do it with CIS creates a
comedy of dichotomies. I presently have enough fuel, I can control afr's with the DWUR, I can program timing with the MSD6AL-2, and keeping the vacuum advance
may fill in the blanks. So I just have to give it a try !!!!!


Where's, Keith, I can't believe he isn't all over this ?????

Cole

Any MAP sensor or pressure gauge should be calibrated so the readings you're looking for are in the middle of it's range. That way you will have a much more accurate reading than if your operating range was at the top or bottom end of it's sensing or display range.

When used with current day EFI, Manifold Absolute Pressure sensors take a quick reading of the ambient barometric pressure when you turn the ignition key through and then past the 'on' position to get to the 'start' position as you start the motor so the MAP sensor and ECU has a current barometric air pressure reference point because barometric air pressure is constantly changing with the weather or the altitude you're at.
I'm curious if the MSD 6AL2 does this. It seems it would have to or else your settings would completely change and become wrong if you drive up or down a mountain or drive through a changing weather front.

I'm perfectly satisfied with the stock distributor advanced around 12 - 15 degrees from stock at idle, and the 8762 boost retard module with it's retard threshold or start point adjustment set to 5psi and the retard slope adjustment mounted in the car to compensate for that.

It doesn't make the car any faster under boost because total advance is about the same then, but it does give it alot more pep at low unboosted speeds and when starting from a stop.
I'd guess it's probably similar to raising the compression around 1/3 to almost a half point and leaving the timing stock as a comparison.

I got physical distributor advance curve modifications out of my system back when doing it over and over and over again while tinkering with old points and condensor BMW's with pertronix and MSD modifications so I have no desire to take apart a perfectly good working 930 distributor that only has around 25,000 miles on it and experiment with reluctor repositioning and centrifical and vacuum advance mechanism springs and pin in slot lengths.

I still have to get some timing tape for the AC pulley... According to MSD telephone tech support the adjustable timing lights are freaked out by the higher energy level from MSD ignition and completely unusable. They say only the plain old timing lights with no advance dial are the only ones that will work with MSD ignition.
I've only tried one adjustable timing light and sure enough it was totally freaked out by the MSD and did not work. It was a cheap one from harbor freight though so I want to try a more expensive higher quality one still.
FWIW, MSD tech support says it's the high energy level and it's magnetic flux around the wire and not the multiple sparks below 3000rpm that confuses the delay circutry in those timing lights.

carry on...

J,

Thanks for jumping, I always look forward to your input. The new MSD isn't here yet so I haven't seen what preperation is needed to set up the MAP feature but, like you say, it has to recalibrate at some point. I would like to hear your input on leaving the vacuum advance operable.

Cole

Hi Cole
I don't know so I don't really have an opinion on leaving the vacuum advance on your car with the MSD you're getting.
Your distributor is a little different than the '87 version I have and yours is likely a little better for performance.

There's people that have alot more experience modifying 930 distributors and ignition than me.

J,

Thanks anyway,

I didn't realize you have the 2 pot distributor.

Cole

So that's what it's come down to, huh? One-potter's vs. two-potter's. If only life were so simple....

My opinion (I left you a PM on this) is that you keep your vac advance. Since you have been able to map out your current distributor curve, you've got the information you need to program your 6AL-2 with that additional advance in mind. Drop your advance weights and springs but don't pin the plate. Keep in mind that I'm not speaking from experience, just logically on this one. JF has much more smarts on the inner workings of dizzy's.

I just wanted to chime in on a few things:

The mechanical and vacuum advance mechanisms are independent of each other. You can disable one without affecting the other.

I would leave the vacuum advance connected on a single pot. It has no effect under boost or over 4000 rpm.

GM 2 and 3 bar sensors are absolute pressure sensors and need no reference to baro in order to work.