Classic Retrofit CDI+: Dyno Results

[Jonny042]

Originally Posted by Mothy

I have to agree with Jeff above.

Plus best value for me in that it replaced an old and risky device with something modern, adjustable, that increased performance in the area where I spend most of my time in the lower rev range.

The ability to avoid a costly 10k rev tacho conversion and have an adjustable rev limiter is a big bonus.

Cost difference with other alternatives is not big.

To me it represented good value. Thanks to Jonny for helping keep our older cars running well.

Tim

Along with all the above things, the ability to have adjustable control over the MFI cutoff solenoid is a huge plus for me, since I did not have the original speed sensitive relay. Again avoiding 40 year old electronics, and simplifying the car, and not adding another box from May Suddenly Die (MSD).

In fact I was one of the first to ask about this as a possibility (I think I figured that instead of controlling a shift light, it would be simple to connect it to the circuit for the cutoff solenoid). Jonny's response was to get back to me in the affirmative after looking into it, and now, after a simple software update, it is listed among the features. How is that for service and support?

[Jonny042]

Originally Posted by Mothy

I have to agree with Jeff above.

Plus best value for me in that it replaced an old and risky device with something modern, adjustable, that increased performance in the area where I spend most of my time in the lower rev range.

The ability to avoid a costly 10k rev tacho conversion and have an adjustable rev limiter is a big bonus.

Cost difference with other alternatives is not big.

To me it represented good value. Thanks to Jonny for helping keep our older cars running well.

Tim

You forgot the ability to lock out the distributor curve and program it with the CDI+!

[QueWhy]

I’m looking to switch from CIS to carbs. I know I need the distributor recurved and the ignition upgraded (MSD seems to be common). Would I be able to solve both of these problems with a CDI+ unit?

[Jonny H]

Originally Posted by QueWhy

I’m looking to switch from CIS to carbs. I know I need the distributor recurved and the ignition upgraded (MSD seems to be common). Would I be able to solve both of these problems with a CDI+ unit?

In a word, yes. As long as the distributor bearings are ok, save your money on a rebuild and mechanical recurve.

Also, see post 163 a few pages back for a CIS car coverted to carbs. You can expect some pretty nice results!

[QueWhy]

Originally Posted by Jonny H

In a word, yes. As long as the distributor bearings are ok, save your money on a rebuild and mechanical recurve.

Also, see post 163 a few pages back for a CIS car coverted to carbs. You can expect some pretty nice results!

Awesome, thanks for the quick reply. I think a CDI+ will be my first step, I can use it with my current CIS setup and then with the carbs when I finally get everything else purchased and ready to install.

[Lundegaard]

Just mounted classicretrofit CDI+on my 1980 911 sc with lamba.
Had it on Dyno in October 2018 just before I drove it in the garage for the winter and it showed 176.8 HP at 4900 rpm and 267NM at 4200 rpm which I was actually very pleased with when the factory spec says 247NM.
But just look what the numbers show now after classic retrofit ignition is mounted, I'm impressed.
191.4HP at 4500 rpm and 294NM at 4200 rpm on a complete standard engine.
The only change is the classic retrofit ignition and another air filter inlet box, nothing else.

[Jonny H]

^ Thanks for posting. Nice result and well done for bringing this back on topic!

I must admit the first few pages of this thread wore me down so it is really nice to see people take the time to post their actual experiences.

[Jonny H]

Nice little 69 T 2.0. These early LWB cars ran standard inductive ignition, with only the E and S models getting CDI systems.

Big uplift in performance installing CDI+ with no other modifications. Still runs the original Marelli Distributor.



https://www.instagram.com/p/CLqthPOl5kX/

[mar2mar]

I've been using a CDI+ on my 70S for the past 4 years and I highly recommend it. It is a solid high quality product. From idle to redline car runs smother, and with less vibrations compared to my rebuilt Bosch CDI.

[Fubawu]

Do you have any comparisons to the MSD 6AL?

[Jonny H]

Thanks for the post. Early 'S' models do seem to respond particularly well.

Lovely looking car btw.

[Jonny H]

Originally Posted by Fubawu

Do you have any comparisons to the MSD 6AL?

Oddly, only on a Jaguar E-type 3.8 6 cylinder. Both MSD and CDI+ made around 25HP over the standard Kettering system. CDI+ showed better mid range power ( 3000 - 5000 ). MSD is not that common over here (UK). In fact, I don't know any 911 engine builders in the UK or mainland Europe who use MSD.

CDI+ is plug and play with the original coil, leads, cap, rotor and it looks right in the engine bay.

MSD wants a new coil (which is a $10 Chinese made coil) , leads and removing resistors from rotors. The primary coil voltage is ridiculously high at 530 volts which is more demanding of coils, leads and also why the rotor resistor burns out. Plus, all that bright red makes my eyes hurt.

By spec:

MSD : Voltage 530v. Spark Interval 1000us, Multispark to: 3000 RPM

CDI+: Voltage 400V. Spark Interval 400us, Dual spark to: 12000 RPM

[Mark Henry]

Originally Posted by Jonny H

MSD is not that common over here (UK). In fact, I don't know any 911 engine builders in the UK or mainland Europe who use MSD.

CDI+ is plug and play with the original coil, leads, cap, rotor and it looks right in the engine bay.

MSD wants a new coil (which is a $10 Chinese made coil) , leads and removing resistors from rotors. The primary coil voltage is ridiculously high at 530 volts which is more demanding of coils, leads and also why the rotor resistor burns out.

Builders use them because they're cheap and plentiful this side of the pond.
Their primary coil voltage is ridiculously high because they are made to fire monster V8's with blowers. In my case, 914/6 conversion, they're a good solution when you have none of the original kit. Plus my PMS/Jarvis/Jaguar twin plug dizzy has MSD guts, so for me it's a plug in.

[mysocal911]

A more recent discussion is here;

Best advance curve for SC 180 HP ROW full stock?

[RDM]

After delaying for two years thinking it was something else, I finally ponied up for the CDI+. Installation was 10 minutes (including checking the timing before and after), and the car runs much better. The mid-range stumble when tipping in the throttle is gone now, and the idle is rock solid. Well thought out, well executed product.

I plan on doing the study and locking down the distributor as part of winter projects. Does anyone have a curve they like for an SC with 964 cams and SSIs that I can use as a starting point?

Strangely, my wife believes the car is quieter now, too. Any basis for that? I'll take it either way....

[mike sampsel]

Originally Posted by RDM

After delaying for two years thinking it was something else, I finally ponied up for the CDI+. Installation was 10 minutes (including checking the timing before and after), and the car runs much better. The mid-range stumble when tipping in the throttle is gone now, and the idle is rock solid. Well thought out, well executed product.

I plan on doing the study and locking down the distributor as part of winter projects. Does anyone have a curve they like for an SC with 964 cams and SSIs that I can use as a starting point?

Strangely, my wife believes the car is quieter now, too. Any basis for that? I'll take it either way....

marvelous, simply marvelous. Dru.
I'll be watching and learning.