Ignition Upgrade Question

[Jnduda]

Has anyone swapped out their stock Bosch ignition with Perma Tune or MSD? Was it worth while for performance gain?

Looking to get a little power gain out of my 3.0 Ltr (75 911) engine but not sure if an MSD unit will show any noticeable performance results.

Thanks

[waynesco1]

All the performance will start to show up on the slippery slope as you wallet gets very thin and starts to burn a hole in your ars and as you start to visualize and come to the conclution I should jist learn how to drive this car first !!!!!!

[dlague]

does the 1975 have points? Not sure I remember.

[Jnduda]

Engine has points, it's the 930.02 (euro).

Likewise, good driving takes you to a level that you want more power. Also don't want to do a complete tear down and rebuild just yet.

[911st]

From what I understand, Porsche makes a great ignition out of the box.

There seems to be no real value to go to MSD unless you are having a problem with miss fires at lower rpms due to a too rich Air/Fuel condition like on a race MFI system or such. Another time would be if you needed an on boost retard function if you were going to turbo.

Put a cat bypass and good sport muffler and maybe have someone that is an expert tune it on the dyno for the best bang for the buck.

Putting on carbs and back dating the exhaust to a pre 74 or headers is a proven set up.

Then concentrate on suspension set up and making it lighter.

[dlague]

The Porsche well Bosch CDI box does a good job. I would keep that and make sure your distributor cap, wires and plugs are in good shape.

In my opinion you will see the biggest difference by removing the points and installing a Hall effect solid state unit such as the Pertronix Ignitor II.


I would STRONGLY recommend replacing the points with a Pertronix Ignitor II unit. This is an easy and quite economical upgrade.....$100.00, and I find it to be really worthwhile. You will not have to worry about point adjustments and the timing getting off because of point wear. Also the spark is very consistent and everything just works better.

Installation is easy. Bolt in replacement for the points in the distributor. You only have to supply 12 VDC to the Pertronix in the distributor.

I find the idle to be more consistent, and the whole ignition more consistent throughout the rev range.

I also installed Nology wires on my 1973 2.7 about 5 years ago and feel it makes a big difference. I am also using a Nology coil.....not sure how big a difference that makes, but it has worked fine.

If you upgrade to MSD later the Pertronix will work well with it.

[Jnduda]

Have you tried some of the new spark plugs on the market? They post 5hp gains in US cars but I have never seen anything for the older Porsche's in terms of numbers.

Thanks of the tips, will do a search for the Pertronix Ignitor II.

[dlague]

don't know about spark plugs. Fresh plugs with a good properly timed voltage is what you are looking for.

My first step would be to be sure that everything in the system is good. Plug wires, plugs, rotor, cap.

If you are still using points, there is a no brainer place to start for more consistant spark and reliability.

Again just my 2 cents.....and my personal experience.

[dlague]

don't know about spark plugs. Fresh plugs with a good properly timed voltage is what you are looking for.

My first step would be to be sure that everything in the system is good. Plug wires, plugs, rotor, cap.

If you are still using points, there is a no brainer place to start for more consistant spark and reliability.

Again just my 2 cents.....and my personal experience.

[dlague]

Pelican parts sells Pertronix II. Available other places. I would be happy to supply help and anwer questions. I want to post a how-to with photos......just don't have a lot of time right now.

there is a Pertronix how-to on this forum. Wiring can and should be simpler than in this post. It is quite and easy job.

Dick