Cdi + questions

[Sailkane]

Has anyone installed a Classic Restoration CDI + system?
Performance gains? What spark plugs and wires?
Looking to upgrade this winter.
Thank You for any information.

[Joe Bob]

If what you have works....stay with it.

[Jonny H]

Our CDI+ system is designed to work with the standard coil, plugs and leads. The dual spark features takes advantage of the fast Bosch black CDI coil. There is no other coil that can charge/discharge as fast. That’s how we can provide multi spark to 10000 RPM.

[QueWhy]

Originally Posted by Jonny H

Our CDI+ system is designed to work with the standard coil, plugs and leads. The dual spark features takes advantage of the fast Bosch black CDI coil. There is no other coil that can charge/discharge as fast. That’s how we can provide multi spark to 10000 RPM.

Bumping this thread with a question for Jonny H.

I have a silver replacement coil, the original black ones are super hard to find and the classic retrofit coil is sold out. Does this mean I can’t take advantage of the dual spark feature? If so what are my alternatives?

[Fred Winterburn]

'It don't mean a thing if it ain't got that swing'. Yeah, if you are timing the sparks to be close enough to matter (200-300µS between sparks maximum), and the coil inductance interferes with the next strike due to stored energy left over from the first spark, you need a low inductance coil to compensate. That helps in two ways. Lower inductance means lower energy losses, and the lower inductance means less destructive interference so the next potential spark in the series will actually 'spark'. The other way to do it, is to time the subsequent sparks such that they are enhanced by the natural oscillation and aid the next spark in the series (constructive interference). But, if brute force is the method, then a low inductance coil for CDI is a must because the timing for subsequent sparks will invariably be 'wrong'. Fred

Originally Posted by Jonny H

Our CDI+ system is designed to work with the standard coil, plugs and leads. The dual spark features takes advantage of the fast Bosch black CDI coil. There is no other coil that can charge/discharge as fast. That’s how we can provide multi spark to 10000 RPM.

[wreckah]

i noticed smoother and little bit healthier bottom end with no difference in ignition mapping. (flat map)

I noticed a big bump in bottom power when changing to a different timing map.

I never really had anyone tune it on a dyno, because quickly after i bought the CDI+, i converted my car to full EFI with spark.

I never really felt a difference at the top, because you are not above 6K RPM so regularly that you can feel these differences...the noise and the exhiliration overpower the experience.

It is a quality unit, great support, looks fab. Great resale value too.

[wreckah]

stock plugs and wires.

[Ginger77]

Is the MSD 8222 coil a good alternative for the black Bosch to use with the CDI+?

[Lundegaard]

I have check this.
Classic Retrofit CDI+: Dyno Results

[dicklague]

I got rid of my Bosch CDI in my 1973 911 MFI 2.7, and installed a more modern CDI. Not Classic retrofit but a good hi quality unit.

MFI can be rich at times. I find starting is much easier and the power is better throughoiut the RPM range. It is also stronger on top.

The Bosch is a 50 year old design with 50 year old parts. Technology and components have come a long way.

[Wasatch 911S]

I replaced my stock CDI in my '72 S with factory MFI about 2 years ago with the Classic Retrofit box and have been very happy. The car starts much easier and the throttle response improved. I also have an AFM installed and the comment above about MFI running rich is true. My AFR improved by just adding this system. I do like the reliability of the modern CDI box vs a 35 set of electronics when out driving. I put my stock CDI on the shelf for the next owner. My plugs look cleaner also. Not sure it added any power, but the car runs great.

With regard to a replacement coil, Johnny didn't offer one when I installed my system so i went with this one from Parts Klassic CDI Ignition Coil. It appeared to have the right specs, but I would love to hear from Johnny if it is still a good match for his system.

[QueWhy]

Originally Posted by Wasatch 911S

I replaced my stock CDI in my '72 S with factory MFI about 2 years ago with the Classic Retrofit box and have been very happy. The car starts much easier and the throttle response improved. I also have an AFM installed and the comment above about MFI running rich is true. My AFR improved by just adding this system. I do like the reliability of the modern CDI box vs a 35 set of electronics when out driving. I put my stock CDI on the shelf for the next owner. My plugs look cleaner also. Not sure it added any power, but the car runs great.

With regard to a replacement coil, Johnny didn't offer one when I installed my system so i went with this one from Parts Klassic CDI Ignition Coil. It appeared to have the right specs, but I would love to hear from Johnny if it is still a good match for his system.

This is what I am hoping to find out too. I’m going to be pretty disappointed if my $1000 CDI+ doesn’t offer any advantage over a $200 Streetfire without sourcing a NLA, nearly impossible to find used(~$300 if you do) Bosch black coil.