Perma-Tune Distributor and CDI

[porschedude996]

Does anyone have any experience on perma-Tune products? I’m thinking about pulling the “Trigger”.

Distributor:

https://www.pelicanparts.com/cgi-bin/smart/more_info.cgi?pn=PRMT-911SC126#techArticlesAnc

CD

https://www.pelicanparts.com/cgi-bin/smart/more_info.cgi?pn=PRMT-911SC906

[HarryD]

Do some reading on this BBS and decide for yourself.

[Tremelune]

There is some debate over the "best" ignition system for these cars, and it changes if you have ITBs and EFI and what not. It seems like the two modern "best" are CDI+ from Classic Retrofit and a 123ignition distributor. If your car is otherwise stock, I'd probably lock the distributor and use the CDI+. If you need to replace the distributor anyway, I'd probably go with the 123ignition...If you're willing to spend money to be "done with it", Ignition123 distributor with a CDI+ seems to be about as good as it gets before you're in a crank-trigger EFI setup. The downside there is cost and overlapping capabilities between the two products.

Tell us more about your engine and goals.

[porschedude996]

Originally Posted by Tremelune

There is some debate over the "best" ignition system for these cars, and it changes if you have ITBs and EFI and what not. It seems like the two modern "best" are CDI+ from Classic Retrofit and a 123ignition distributor. If your car is otherwise stock, I'd probably lock the distributor and use the CDI+. If you need to replace the distributor anyway, I'd probably go with the 123ignition...If you're willing to spend money to be "done with it", Ignition123 distributor with a CDI+ seems to be about as good as it gets before you're in a crank-trigger EFI setup. The downside there is cost and overlapping capabilities between the two products.

Tell us more about your engine and goals.

Thanks for speaking up.

My car is a 1983 911SC, stock 3.0L, 49 State Emissions, no California certification.

I’ve been working on the CIS for some time getting dialed in to repeat a miserable 1st emission test (Gross Polluter).

I’ve removed tested all the air valves, rebuilt distributor, checked/set timing. Adjusted valves, replaced injectors and o-rings, new plugs, ignition wires, Ran CIS pressure tests. Replaced most flex vacuums hoses. Smoke tested the intake system, no leaks. Repaired, adjusted Auxiliary Air Regulator. New WUR timer switch. New cat and Lamda Sensor. Replaced accumulator, and fuel filter.

Found the retard side of the distributor vacuum pod unable to hold any vacuum.

Tested Frequency Valve with a oscilloscope running about 45% Duty Cycle at idle, 50-65% off idle and rapidly advancing throttle. No miss firings, no smoke.

Cold starts well, warm starts well. Runs smooth.

My worries are the retard side of the vacuum/retard pod. The minus 5 degrees that is pulled in at idle is not functioning which lowers CO and Hydrocarbons at idle.

My plans are to keep it mostly stock and for the remainder of my life.

I was able to find a modified vacuum advance/retard pod, was not happy with the modifications to this Mercedes pod.

I think the retard function is my last steps before second emission test.

Using the Perm-Tune CDI and Distributor. That would fix the retard problem. I did purchase a Rauch and Spiegel dual diaphragm pod, but would surely fail the visual part of the emission inspection. No CARB EO approval, they don’t plan on presenting it to CARB for approval.

Being the Perma-Tune looks stock, works better than stock, and they plan on getting the CARB approval, I think its best to buy the Perma-Tune CDI, Distributor, and Coil.

Did I miss any points of interest?

[mysocal911]

Originally Posted by Tremelune

There is some debate over the "best" ignition system for these cars, and it changes if you have ITBs and EFI and what not. It seems like the two modern "best" are CDI+ from Classic Retrofit and a 123ignition distributor. If your car is otherwise stock, I'd probably lock the distributor and use the CDI+. If you need to replace the distributor anyway, I'd probably go with the 123ignition...If you're willing to spend money to be "done with it", Ignition123 distributor with a CDI+ seems to be about as good as it gets before you're in a crank-trigger EFI setup. The downside there is cost and overlapping capabilities between the two products.

Tell us more about your engine and goals.

Really? And how did you arrive at that conclusion, i.e. you've done extensive testing and you have data you can provide, right?
Furthermore, you evaluated these two ignitions for long term reliability, right? Have you found specific problems with the original Bosch CDI?
As an engineer, can you provide some technical data, e.g. spark energy, spark pulse width & voltage, etc. for your recommendations?

[mysocal911]

Originally Posted by porschedude996

Thanks for speaking up.

My car is a 1983 911SC, stock 3.0L, 49 State Emissions, no California certification.

I’ve been working on the CIS for some time getting dialed in to repeat a miserable 1st emission test (Gross Polluter).

I’ve removed tested all the air valves, rebuilt distributor, checked/set timing. Adjusted valves, replaced injectors and o-rings, new plugs, ignition wires, Ran CIS pressure tests. Replaced most flex vacuums hoses. Smoke tested the intake system, no leaks. Repaired, adjusted Auxiliary Air Regulator. New WUR timer switch. New cat and Lamda Sensor. Replaced accumulator, and fuel filter.

Found the retard side of the distributor vacuum pod unable to hold any vacuum.

Tested Frequency Valve with a oscilloscope running about 45% Duty Cycle at idle, 50-65% off idle and rapidly advancing throttle. No miss firings, no smoke.

Cold starts well, warm starts well. Runs smooth.

My worries are the retard side of the vacuum/retard pod. The minus 5 degrees that is pulled in at idle is not functioning which lowers CO and Hydrocarbons at idle.

My plans are to keep it mostly stock and for the remainder of my life.

I was able to find a modified vacuum advance/retard pod, was not happy with the modifications to this Mercedes pod.

I think the retard function is my last steps before second emission test.

Using the Perm-Tune CDI and Distributor. That would fix the retard problem. I did purchase a Rauch and Spiegel dual diaphragm pod, but would surely fail the visual part of the emission inspection. No CARB EO approval, they don’t plan on presenting it to CARB for approval.

Being the Perma-Tune looks stock, works better than stock, and they plan on getting the CARB approval, I think its best to buy the Perma-Tune CDI, Distributor, and Coil.

Did I miss any points of interest?

You are aware the most all emission testing, e.g. CA, is not done at idle?
And CO and hydrocarbons are not reduced significantly by retarding the ignition timing, right?
Your Lambda ECU in closed loop should be reducing the CO to less than 1.0-1.5%, if the base open-loop mixture is set properly.

Your engine emission problems are NOT going to be helped by switching to an aftermarket ignition!

[porschedude996]

I beg to differ. I live in an area where it is not an enhanced inspection on a chassis dyno. Half the test is in fact at idle. 2,500 rpm no load and idle at 900 rpm. I’ve found that the retarding to zero advance or ATDC is beneficial in reducing the emissions. My CO was low and HC was 4 times the listed Porsche specifications on the emissions sticker.

[mysocal911]

Originally Posted by porschedude996

I beg to differ. I live in an area where it is not an enhanced inspection on a chassis dyno. Half the test is in fact at idle. 2,500 rpm no load and idle at 900 rpm. I’ve found that the retarding to zero advance or ATDC is beneficial in reducing the emissions. My CO was low and HC was 4 times the listed Porsche specifications on the emissions sticker.

None of the so-called "modern" ignitions is going to solve that problem. Remember, you not only need to reduce your emissions,
but comply with the maximum requirements. A properly functioning and setup CIS fuel injection system can typically pass most emission tests.

Check the functioning of CIS:
1. test the control & system fuel pressures
2. test the Lambda for;
a. O2 sensor input pin 2
b. cold enrichment switch input pin 7
3. 12V to the WUR heater
4. auxiliary air function
5. open-loop warm CO mixture set to 1.5%

[porschedude996]

Originally Posted by mysocal911

None of the so-called "modern" ignitions is going to solve that problem. Remember, you not only need to reduce your emissions,
but comply with the maximum requirements. A properly functioning and setup CIS fuel injection system can typically pass most emission tests.

Check the functioning of CIS:
1. test the control & system fuel pressures
2. test the Lambda for;
a. O2 sensor input pin 2
b. cold enrichment switch input pin 7
3. 12V to the WUR heater
4. auxiliary air function
5. open-loop warm CO mixture set to 1.5%

As stated above, i’ve bench test each of the majority components. Shy the Frequency Valve, and I believe it is operating as tested with a oscilloscope. I have an old automotive CO meter, but would like to check the accuracy.

Going back to the distributor retard. I is integral to the emissions system. I had an old 1967 Jeep pickup truck that I put 5 advance static and the hydrocarbons went well over the maximum. Brought it back to TDC (spec) and it passed fine. I can’t find a any Advance/Retard pod for the 2983 911SC. I did find a New Porsche OEM distributor. I’ll install that, check the Fuel-Air Ratio and CO. Maybe before and after the Cat. The Cat is new 49 state unit.

[Jonny H]

Agree, sort out the CIS first but disagree that a modern ignition can't reduce emissions.

We don't have the the closed-loop lambda cars in the UK, they are all open loop - but we still have the emissions test. We have many customers reporting lower emissions with CDI+, more often on the Turbo cars.

[porschedude996]

Originally Posted by Jonny H

Agree, sort out the CIS first but disagree that a modern ignition can't reduce emissions.

We don't have the the closed-loop lambda cars in the UK, they are all open loop - but we still have the emissions test. We have many customers reporting lower emissions with CDI+, more often on the Turbo cars.

I agree that the P-T will not improve over the stock unit, but in desperation to get everything working as designed, “vac pod”, I was going to get the P-T. I think the ability to hold the distributor spec to the ideal value is good, but I wouldn’t expect it would really make a difference if you had a proper working OEM.

[mysocal911]

Originally Posted by porschedude996

I agree that the P-T will not improve over the stock unit, but in desperation to get everything working as designed, “vac pod”, I was going to get the P-T. I think the ability to hold the distributor spec to the ideal value is good, but I wouldn’t expect it would really make a difference if you had a proper working OEM.

An ignition system that would contribute to reduced emissions is the IDI (inductive discharge ignition), which typically has a spark dwell time of about 10X a CDI,
i.e. approaching a millisecond. All present day ICEVs (internal combustion engine vehicles) use an IDI system. Some of the aftermarket ignitions systems,
e.g. https://123ignition.com/products/?filter_brand=porsche&filter_cylinders=6, provide a simple solution to directly drive an ignition coil.
The IDI is inherently more reliable than a CDI, no capacitor & less components.

[AndrewCologne]

Originally Posted by porschedude996

My worries are the retard side of the vacuum/retard pod. The minus 5 degrees that is pulled in at idle is not functioning which lowers CO and Hydrocarbons at idle.

CO will not be significantly affected by the ignition retard itself at idle, Im with Dave here.
Beside reducing HC Emissions an ignition retard at idle results in a much hotter exhaust gas flow which makes the OX sensor getting hotter at idle and therefore reacting much better.

[Jonny H]

Originally Posted by mysocal911

An ignition system that would contribute to reduced emissions is the IDI (inductive discharge ignition), which typically has a spark dwell time of about 10X a CDI,
i.e. approaching a millisecond. All present day ICEVs (internal combustion engine vehicles) use an IDI system. Some of the aftermarket ignitions systems,
e.g. https://123ignition.com/products/?filter_brand=porsche&filter_cylinders=6, provide a simple solution to directly drive an ignition coil.
The IDI is inherently more reliable than a CDI, no capacitor & less components.

Hold on, we are to take your words as gospel but everyone else has to provide 'data'?

[porschedude996]

Thanks everyone for insightful banter. I’m recovering from shoulder surgery (12/30/22) and will not have the ability to move on my project further. I’ll post my emission test results when i’m able. Can’t work in shop, can’t drive… It sucks at the moment.

[Tremelune]

Meet Len, everyone. He gets banned here from time to time. Something about ignitions and air conditioning lights sets him off.

[Schulisco]

I recently discovered this excellent video from Klassik ATS / Curt to the 123igniton:



https://youtu.be/4FYkm7vq8zs

Thomas

[porschedude996]

Originally Posted by Schulisco

I recently discovered this excellent video from Klassik ATS / Curt to the 123igniton:



https://youtu.be/4FYkm7vq8zs

Thomas

Thanks Schulisco for the link.

I’ve seen videos from them and purchased from them with much delight. The description on our host site states the proper programming is installed. In the Klassik video he says it doesn’t have the OEM curves. I commented on his video asking his thoughts on the current issued distributors. And also could he provide the file or values.

[Jonny H]

^ Note that he is using the 123 with the CDI box. So he can program a curve with the 123 and keep the original CDI ignition.

Another way to achieve the same result is to keep your 911 SC distributor and use one of our CDI+ boxes which is also fully programmable for ignition curve and rev limiters. You can lock the advance mechanism in the SC distributor easily or we sell a locking device.

The 911 SC distributors are ultra reliable in my experience - never seen a pickup failure.

[Jase77]

Hey Jonny and fellow Pelicans.

I have a 1977 911S and as far as I am aware I cannot lock the distributor advance in position. (If anyone knows better than please let me know)

I have the Classic Retrofit CDI+ installed and now I want to upgrade my distributor. Can anyone recommend an electronic points swap please?

I had the 123 distributor in my MGB a few years back and it was a very well made part that made a huge difference. Would it make sense to run this as well as the Classic Retrofit CDI+?

Cheers,
Jason.