Ultimate 930 Distributor, advance, retard, timing, Turbo lag, MSD, mod, thread.

[911st]

Viva la CIS and those other nutts that love it to!

[911st]

Thierry,

No.

I do believe you and applaud you.

You have got this stuff down and I wish I had some of you skills.

You also have better fuel and weather at your disposal. There is a difference between street duty and track. Your success in doing helps us to question how far we can go.

To offer a sobering thought, I knew of one stock 89 930 that ran 1 bar for a long time on the street. Then one day I saw his motor all over the work bench after he burned a piston. Worked great for years. Then it was a hot-day, or he had a dirty injector or something...

It is just how far one wants to push the limits. I know the water cooled turbo guys run those types of values often on even a higher base compression. when I had my dyno work on my C2T the guy wanted to stay around 12.2 AFR. No I accept one EFI 930's suggestion that a EFI 930 running the fuel we have available today should stay to the rich side of 11.8 AFR. With CIS I might be a bit richer than that.

I still have no idea how far we can push the advance on boost. I just have a good idea where the factory came in on the 930.

Keep up the good work.

[smurfbus]

Thierry, what fuel do you use? V-power 100 oct RON? Nice gadget that USB scope. Do you have more info of it?

[JFairman]

Thanks for the info Cole...
I was thinking of calling MSD about that but havn't done that yet.
The tape for a 5.25" diameter pulley is cheaper than buying another timing lite with the advance delay dial on the back.

Jim

Originally Posted by cole930

J,

Been meaning to let you know. MSD sells timing tape in packs of 8 you can find it on Evilbay runs about $4.00 covers pully dia. up to 8".

Cole

[cole930]

Jim,

My old Mac Tool timing lite croaked last week. Found a special going on Amazon
for Equus 3568's for $60.50. That's a good buy and it will be here this comming week.


Cole

[JFairman]

I've heard some timing lights are fried by MSD ignitions even though they are induction triggered.

Maybe the MSD multiple sparks below 3000rpm are too much for some of the older ones and they need something to buffer the signal to hang with it.

Jim

[WinRice]

Originally Posted by JFairman

I've heard some timing lights are fried by MSD ignitions even though they are induction triggered.

Maybe the MSD multiple sparks below 3000rpm are too much for some of the older ones and they need something to buffer the signal to hang with it.

Jim

Some of the old lights couldn't filter out the multiple sparks, so you didn't get a reliable reading, never saw one damaged because of it. Maybe a bad plug wire with cracked insulation could put the HV directly to the pickup?

FWIW my Equus 5568 works fine with all my MSD 6A equiped vehicles, so I'm guessing the 3568 would do fine.

[cole930]

Guys,

The Old One needs some help here. My age, stubbornness, and total distain for computers forces me to ask; could any of you tell me what hardware I need at the usb port on the DWUR to communicate with my
wireless laptop. Before you start pimping about my lack of computer skills
you have to understand I took my college final in Statics with a slide rule
and I still have the first TI four function calculater.

Jim & Win,

The MSD did not get my timing light , it was a Chevy pick up. My buddy managed to back over it. He was bumping the ignition to get to TDC and left the truck in gear.

Cole

[JFairman]

MSD timing tape ebay search result.
MSD Ignition 8985 Timing Tape 5.250 to 8 in. Dimeter:eBay Motors (item 370302115184 end time Dec-12-09 06:03:24 PST)

I could probably just print this at the correct size/resoloution, cut out the bottom strip or resize the top one and try glueing it on...


If thats not right I can clone out the MSD logo in p-shop and resave it in about 3 seconds.

[mark houghton]

Originally Posted by cole930

Guys,

Before you start pimping about my lack of computer skills
you have to understand I took my college final in Statics with a slide rule
and I still have the first TI four function calculater.

Cole

Cole, you made Mr. Gimpy laugh on that one! Did you keep your slide rule in a leather pouch attached to your belt? At one time someone showed me how to use one of those arcane instruments, but then I bought my very first TI new-fangled calculator and trudged off to the U. It was high-tech at the time, cost something like $75, and besides the normal add subtract multiply divide functions - and a memory function, it also did square roots. What a bonus! So, who out there still knows how to calculate square roots long-hand....hmmmm? (and who really cares).

You ought to sell the TI on Ebay....probably worth - well, nothing. Or put it in a time capsule and bury it in the backyard.

[ertech]

Anyone have a step by step with pics in how to modify the limit on the distributor internals .
Thanks

[JFairman]

"The MSD did not get my timing light , it was a Chevy pick up. My buddy managed to back over it."
lol... don't ya hate it when that happens..

"Anyone have a step by step with pics in how to modify the limit on the distributor internals."

If you take it apart you'll see what you have to do.
There's 2 pins on the mechanical advance plate that fit into slots on an adjacent plate that limit how far the advance weights will advance the breaker plate, reluctor, or whatever it's called in an electronic distributor.
Last time I did it was on an old points type bosch euro distributor on a BMW.

You can put bushings on the pins to make them thicker and as long as they are not too thick to fit in the slots then that will limit their travel in the slots, or you can put something in the ends of the slots to shorten them and limit the travel of the pins.
It's made of steel so you could braze some brass into the slots and regrind them with a 1/4" carbide burr in a die grinder to the length you want.

That would probably be alot of trial and error and repetitively removing and installing the distributor until you got it where you want it.

An ebay deal on an MSD 8762 BTM may be a more attractive alternative and you can adjust the timing under boost from inside the car on the fly.
There are 2 models of the MSD Boost Timing Module. One is for MSD ignitions and the other is for OEM and other CDI's.

With a loud muffler or zork it may be impossible to hear trace pinging while the windows are rolled up under full boost if the timing is too far advanced for the fuel octane, boost, and temperature conditions though.

[WinRice]

Originally Posted by cole930

I took my college final in Statics with a slide rule

Post or Pickett made out of Hemmi Bamboo?.........................LOL

My Dad gave me one when I was young, and I actually learned how to use it.

[Thierry25]

Originally Posted by smurfbus

Thierry, what fuel do you use? V-power 100 oct RON? Nice gadget that USB scope. Do you have more info of it?

Hello

I am using EURO 98 fuel.

As to the scope, I bought a "PICOSCOPE 2204 "

You can see it on the following link .

PicoScope Ultra-Compact Oscilloscopes from Pico

For those who are interesting to make similar measurements, the flywheel trigger must be connected via a differential sensor or via the "hot" (+) output only... the (-) of the trigger can not be connected to the ground .

[JFairman]

"could any of you tell me what hardware I need at the usb port on the DWUR to communicate with my wireless laptop."

I remember people saying the DWUR uses a serial port connection, or maybe it's just the early versions.
Strange they used that since those have been kinda obsolete and usually absent from laptop PC computers for a few years now.

I think you need a serial to USB port adaptor.
It's a small passive device and i don't think they cost much.

[Thierry25]

Originally Posted by 911st

Thierry,

No.

I do believe you and applaud you.

You have got this stuff down and I wish I had some of you skills.

You also have better fuel and weather at your disposal. There is a difference between street duty and track. Your success in doing helps us to question how far we can go.

To offer a sobering thought, I knew of one stock 89 930 that ran 1 bar for a long time on the street. Then one day I saw his motor all over the work bench after he burned a piston. Worked great for years. Then it was a hot-day, or he had a dirty injector or something...

It is just how far one wants to push the limits. I know the water cooled turbo guys run those types of values often on even a higher base compression. when I had my dyno work on my C2T the guy wanted to stay around 12.2 AFR. No I accept one EFI 930's suggestion that a EFI 930 running the fuel we have available today should stay to the rich side of 11.8 AFR. With CIS I might be a bit richer than that.

I still have no idea how far we can push the advance on boost. I just have a good idea where the factory came in on the 930.

Keep up the good work.

Hello Keith

Sorry, maybe I misunderstood your last post.

Something I can tell you about the AFR. As said, I ran about 8000km with my car since I made the setup ( and engine rebuild) . My AFR was adjusted arround 11.8. Recently, my workshop inspected the spark plug. It was really black with few little stain of not complete combustion.

Just after this inspection, I changed my datalogger ( which was deffective for EGT input). So after changing, I was able to measure the EGT. So I made both 11.8 and 12.5 AFR test.... The EGT is decreasing a little bit at high RPM ( beyond 5500 rpm) while I tried 12.5. ( So the EGT is higher with 11.8). However, the EGT doesn't increase on the max torque range ( from 3700 to 5200).

Most of people ( me either before) think it is a good point to decrease AFR to nearly 12 until the red line ( 6500). At present time, I suspect Porsche got some good reasons (considering the original timing at high RPM) to adjust the original AFR to nearly 13 at high RPM. Past the max TQ point, I think the air filling in the barrels is low. As the iginition timing is also a bit low, it is probably not a good thing to increase AFR...

As to the fuel, I don't know what is the standart in US (Sorry for my poor knowledge) . Do you have fuel similar to EURO 98 ?

As to the weather, we reach about 35°C during summer in my province... it is true that during days at those temp, I don't like to pull too much my engine.

As you , I like the CIS !!!!!!!!!!!

[Thierry25]

Originally Posted by mark houghton

Good stuff, Thierry. Unfortunately I haven't a clue on the differences for a C2T vs. my '87 930. I would be very reluctant to run 25 degrees advance on my car at 1.0 bar boost. Maybe 18, or on a nice cold winter day and fresh high octane gas maybe 20. I can't believe you're getting away with that timing unless your compression ratio is something like 6:0:1. It's worth thinking about!

Dear Mark

No my compression ratio is strictly stock .

As said before, I use standard EURO 98 fuel.

I do believe the detonation or knock are much far away from the usual beliefs. That's probably why some tuners can reach such high torque and power (I speak about 500 to 600 HP ) . There is no secret..... they fill much more air inside the barrels (with more fuel of (course) ...and they are still using ignition equal or superior to 21°.... So using a 25° or more on a midly modified C2T/930 can make sense.

Having said that, we all know here that a power/ torque increase always decrease engine reliability !!!

[mark houghton]

Originally Posted by Thierry25

Dear Mark

No my compression ratio is strictly stock .

As said before, I use standard EURO 98 fuel.

I do believe the detonation or knock are much far away from the usual beliefs. That's probably why some tuners can reach such high torque and power (I speak about 500 to 600 HP ) . There is no secret..... they fill much more air inside the barrels (with more fuel of (course) ...and they are still using ignition equal or superior to 21°.... So using a 25° or more on a midly modified C2T/930 can make sense.

Having said that, we all know here that a power/ torque increase always decrease engine reliability !!!

I suspect you are correct. What it all comes down to is engine longevity and the cost for rebuilds. For the track racer with sponsers or just plain deep pockets, it's less of an issue - knowing right up front that competing at that level takes a different focus and financial committment. But for street guys like me that just like to terrorize the surrounding backroads occasionally, for us to really push the tuning envelope would be foolish. But still, we want the strongest performing machines we can get....so it's a real balancing act sometimes.

98 octane fuel? 93 is the highest available in my town.

[JFairman]

"Do you have fuel similar to EURO 98 ?"
Unfortunately the highest octane pump gas in the states is 93.
Big difference from 98 so that alone lets you run more advance or more boost or a little of both.

************************************************** *************
Mark and Cole, if you see this I did more short duration 3rd gear full boost 1.1 bar acceleration runs on the interstate last night with the windows up so I can hear the motor good while it was about 70 degrees out.
The intercooler was not heat soaked and gas is Chevron 93 octane pump gas with "at least 10% ethanol" here in S. Florida.

I have a modified Imagine Auto/Flowtech USA fuel head and B.L. adjustable WUR keeping it sane with high boost control pressure's so my AFR's are a little richer/safer than stock up there.
I don't put my cars specs in my profile so it always shows in a post, so I'll mention the car has a half bay garretson long neck intercooler on it and k27 7006 turbo with manual boost valve controller and 964 cams which have more lift, different lobe centers, and a little more overlap compared to SC cams.

At around 5000 rpm I could hear the beginnings of faint trace pinging from the motor with the MSD 8762 BTM boost threshold or start point set to 5psi and pinging started with the slope dial set at 1 degree retard per psi of boost.

When you hear the begiining of trace pinging that means advance is on the edge and is as far as it should be allowed to go.
As you know any more advance will not make any more power and will eventually hurt the motor.

Turning the boost retard slope knob to halfway between 1 and 2 degrees per psi of boost made the trace pinging go away and I couldn't hear any pinging or detonation but these were short duration 3rd gear runs because you come up on I-95 traffic in front of you quickly.

Anyway, the short version is we both have the same year car with the same distributor.
The distributor is turned clockwise and advanced as far as the adjustment slot allows, both vacuum lines are hooked up, the MSD 8762 retard start point is 5psi and the seperate boost retard slope knob is at 1.5 degrees retard per pound of boost for the best performance I've gotten so far.

I still havn't put timing tape on the engine pulley and pressurized the 8762 hose nipple with 15 psi and held the motor at 4000+ rpm with a timing light to see what timing actually is, but I eventually will..

If it was summer hot out I may be safer to leave the slope knob set to 2.
I like having the fast acting slope adjustment in the car on top of the autoheat box.

Next time I have the intercooler off I'll remove the distributor and lengthen the adjustment slot in the advance direction a little so I can try more initial advance, then set the slope knob to 2 and try that.

With slightly longer duration cams like 964 compared to SC or stock, the intake valve closes later in the beginning of the compression stroke so static compression is lower, (but at high rpms with ram effect [and boost] it becomes higher) and you can run more initial ignition advance than a motor with shorter duration cams because of that.

[cole930]

Jim, Win, and Mr. Gimpy

My dad did the same with me but he took it away because I was in the 5th grade and was doing my homework with it. He told me I need to memorize my multiplication tables before I could use it.

No leather case on the belt or nerd pack in the pocket. I was the only guy in the class with a leather jacket and and old junk Harley Springer for transportation, Now that I remember times like that, I guess I have always been socially unacceptable.

Jim is making me Jones for a 930 fix. It's been so long I can't stand it. I may have to come see one of you guys and bribe you with beer for a ride.


Cole