Does it seem like the stock distributor advance curve is lazy? Only reached 29.3 degrees at 5000 rpm.

Will be interesting to see an optimized advance curve, and how much it changes the power.

I assume you will get plunked on the torque not crossing hp at 5252.

Nice power from the engine too. Cdi+ seems to help some, in stock trim. 2-3 hp gain.

It's pretty obvious from the charts that if your Bosch CDI is still working, and/or can be repaired reasonably, there is NO reason to switch to the CDI+...

And what happened to the "gain" below 2400 RPM?

"..We..."

And how many of that "we" team is/was involved in the CDI+ design..?

And just what level is your contribution to that team..??

And still, what is the advantage of a 10 degree spark predictive computation vs a 60 degree one..??

Wwest, here's your answer:
NUNYA.

Torque and horsepower always cross at 5252 since:

HP = Torque x RPM ÷ 5252

(Some dynos use delivered torque which is scaled though)

5 to 10 ft-lbs of extra torque across the rev range is most certainly noticeable in the driver's seat.

Yes, when we get on to timing changes it will get interesting.



[Mr West, from this point on, I am not going to respond to any of your questions or comments. If you want to know more about who we are, I suggest you contact one of our clients]

Thanks Johnny H, at last, for the good comparative data. Some of the very small increase in torque
at various points can possibly be explained by the very small increase in advance of the CDI+ over
the Bosch CDI, i.e. for every one degree in advance, the typical increase in HP is about 3-4 HP.

Bottom Line: The 50 year old Bosch CDI technology doesn't "leave much on the table".

Except that the cdi+ advance was a tick less than the Bosch. And delivered more torque and power.

Thanks for the compliment, but I wish I had his Porsche knowledge and background.
I heard he does work for the SoCal Porsche dealers and independents troubleshooting
and rebuilding ECUs. Maybe at a future Porsche event, I may meet the guy.

True at some points, but the difference overall is "in-the-noise-level".

^ That's right. We deliberately disadvantaged the CDI+ in the 4500 rpm run by retarding it 2 degrees.

Results were the same, more torque.

I agree, when you don't have a good, responsive, answer then no answer is best.

Did you get hurt patting yourself on the back like that? And you have the balls to even advertise yourself.

That is so lame and obvious. Good grief.

^ Bit of a contradiction there! First you say that 1 degree makes 3-4 HP difference, then you say that 1 degree is in the noise and makes no difference?

The second statement is closer to the mark. On this engine, 1-2 degrees did not make a broadbrush step change in power across most of the rev range. Hardly measureable.

The CDI+ however, has given a step change in power output across most of the rev range. This in itself is proof that the CDI+ is not messing with the timing in any way. The fact that the timing is measured independently is further validation.

For those who are thinking that 5 - 10% is not significant, think again.

Neil tells me that if you had an extra 10% power at the top end you would hardly notice. Yet to gain 5 - 10% torque in the mid range makes a significant difference to acceleration.

oh that explains a lot. cheers.

that's the general consensus given the similarities in style, diction, and generally behaving like an "BLEEP"

Having personally tuned a lot of older engines and converting them to a modern ignition system where you can adjust the timing with RPM based maps is definitely a bonus.

Sure if the mechanical max advance is optimum for the engine then no gain can be had at the top end but mid range is where we spend 90% of our time. Increasing the area below the dyno line is the important part, a car can feel transformed by a custom timing map. I would definitely recommend this device to anyone wishing to add some fun to their car. Wideband monitoring would be crucial for optimum results.

Jonny H... congratulations on your hard work!!

Thanks Omegaman. Yes, a whole lot of work had gone in to this. I just checked the original design document and found it was dated June 2013! So two years and 9 months!

A report on the CDI+ dyno test conducted by Neil Bainbridge at BS Motorsport is now available to download.

Click on the PDF towards the bottom of this page: CDI+

Jonny, Do you plan on doing a best power dyno run? it seems all the tests done were using the same timing plot as the standard dizzy. I would have thought you could get some decent gains if you increased the advance low down.

Jonny, have you compared the discharge current into the coil between the old Bosch unit and your CDI+ ? Many times during the repair of the old Bosch units, I find the discharge capacitor is on its way out ... often only slapping the coil with about 1/2 the current that a new part provides. I was wondering if you had verified that you were getting an apples to apples comparison ... i.e., if you are using an 'old' Bosch unit that has its original, possibly degraded, capacitor?

That all being said, hats off to your product ... the concept of being able to program an advance curve is cool, even if it does require some software (wink! wink!) --Bob