Settings for Electromotive HPX ignition

[chuckw951]

Hi,

I have the electromotive HPX ignition in my car.
Here is a link to the product
The motor is a 1982 911SC motor with 9.3 to 1 compression (I believe) and PMO carbs. P&Cs are stock so I'm using CIS pistons. Also using stock cams.

I was given this information to use as the initial settings.

initial advance: 10 degrees
advance added at 3000: 32 degrees (+/- 1 degree)
advance added at 8000: 2 - 4
rpm limit: factory spec for '82 SC (what is redline? to be safe I set it at 5900rpms)

I am using Bosch W5D plugs gapped at a 27,000th.

What settings are other folks using on their single plug HPX ignitions? Am I using the right plugs? How about the plug gap?

Electromotive has the user manual online, but I don't quite understand the part about ignition advance.
Link to user's manual

Thanks.

Chuck

[cstreit]

Chuck,

Those settings sound about right. I used a few degrees less than that, but I am running twin plug. My settings are at:

Initial = 8 deg
3000 = 29 total (+21)
8000 = 26 total (-3)

You can set your rev limit higher though. 6200-6500 would be plenty safe. I'm using the standard plug-gap, I think at .035?

Not sure about the plugs though, I'm using NGK. I would stick with a stock heat range.

What are you having trouble with regarding the advance?

[chuckw951]

Chris,

Thanks for the info.

Originally posted by cstreit

What are you having trouble with regarding the advance?

I don't think I'm having any problems with advance but want to make sure that it set to deliver the best performance. I think I will bump up the rev limiter a bit.

[cstreit]

Well I know plenty of guys that run up to 35 degrees of advance at 6000 RPM... But you have to watch for pinging. You can probably advance a little more without worrying.

[thabaer]

How you you guys with HPX feel about replacing Magnecors every year

I'd hope tough wires would be good for 5 years with the HPX, did the manufacturer say different or just not want to talk about it ?

[cstreit]

I've never heard of replacing them every year... where did you see this?

Gawd I hope not considering what a set of 12 pre-cut costs!

[mm86911]

I run similar setup with W6D on track and W7D for street - both gapped at .032

[thabaer]

Originally posted by cstreit
... where did you see this?

In the PDF file for the HPX user guide, sounds like CYA FUD because they are worried about their higher voltage cooking wires.

Exactly the kind of thing I would blow off until I saw empirical evidence of a FUBAR problem.

need any more acronym zombie madness ? woof.

[chuckw951]

Originally posted by cstreit
Well I know plenty of guys that run up to 35 degrees of advance at 6000 RPM... But you have to watch for pinging. You can probably advance a little more without worrying.

Which dials do I adjust to get 35 degrees of advance at 6000rpm?

[chuckw951]

Originally posted by thabaer
In the PDF file for the HPX user guide, sounds like CYA FUD because they are worried about their higher voltage cooking wires. [/B]

Page two of the PDF file "Warnings and cautions" See #3.

"1. DANGER! The HPX generates high voltage that can be lethal. Do not ever touch a coil tower or spark
plug wire when there is a chance of a spark.
2. Without the spark plug wires on the coils and spark plugs, the system will generate dangerous levels of
voltage that can damage the HPX. This can also lead to fatal electrocution.
3. Do not let the spark plug wires touch the block, head, frame or body. The power of this ignition can burn
through most spark plug wire insulation. Use a quality 8mm (or larger) wire with two piece spring loaded
contacts and wire separators. Replace spark plugs wires every year (recommended)."

Any product that could cause "fatal electrocution" has to be cool. I think these warnings were recommended by the lawyers. I'm not going to replace my wires every year. I'll take the risk.

[cstreit]

CHuck,

Initial Advance at +10 degrees
3000 RPM Adv at +25
8000 RPM Adv at -4

THe effects of each advance dial are additive.

[chuckw951]

Originally posted by cstreit
CHuck,

Initial Advance at +10 degrees
3000 RPM Adv at +25
8000 RPM Adv at -4

THe effects of each advance dial are additive.

Thanks, I'll try those settings.

[chuckw951]

Originally posted by cstreit
CHuck,

Initial Advance at +10 degrees
3000 RPM Adv at +25
8000 RPM Adv at -4

THe effects of each advance dial are additive.

I tried these settings. My initial advance was set at like +12. I turned it down to +10 and the car started easier. Interesting.

I drove around for a hour or so and the seat of the pants meter tells me that the car has more top end power, but less mid-range pull. Does that make sense?


Chuck

[cstreit]

Chuck,

12 is really too high for intial advance and would result in harder starting. In fact the Electromotive and others have the ability to temporarily advance or retard the timing curve. Often high compression race cars will dial timing back to ZERO(!) to make them startable.

If you are flatter on the mid-range, you might try dialing a little advance out. In general advanced=horespower, retarded=torque. The electromotive curve in the mid-range is MUCH more advanced than stock.

Here is a graph that I used to define it when I dial in my curves for particular tracks...



The green and red are the top and bottom ranges for the factory advance curves on an early SC motor. The blue represents the initial advance curve from electromotive... I've found that while this setting works well in my race car with a close ratio gear box it doesn't work as well on a street car.

I think the higher advance at 3000RPM "steals" torque but gives a better HP curve. THis isn't necessarily proven or even scientifically accurate, but only based on my subjective experience at the track.

So try something like:

Intial +10
3000 RPM +(10-12)
8000 RPM +(8-10)

And I bet that will get rid of your flat spot.

chris

[Lorenfb]

Once you get above about 40KV on the coil output, it's of little value and
just stresses the whole ignition system. The same goes for the spark energy.
Anything over 60 to 100 millijoules is of little value. Check out this web site
(www.systemsc.com) on the Technical page in the Ignition Systems section.

[cstreit]

Loren,

I'm not sure how this ties in, can you elaborate?

[Lorenfb]

Chuckw951 raised the issue of the HPX high voltage. My response
assumed that it was one of those aftermarket units where extra
high energy and voltage is part of the marketing claims.

Sorry, to divert from the key focus which is timing. Also, this is
a great thread from the standpoint of setting the proper advance
curve. This is in contrast to what we've seen on the 3.2 discussion
threads, i.e. a little more intelligence and reality.

[cstreit]

Thanks Loren, I forgot about the "voltage and wire replacement" bit earlier in the thread!

CHeers.


Chuck,

Please post back if you have positive results!

[chuckw951]

Originally posted by cstreit

Please post back if you have positive results!

Ok, thanks for the good info, I'll try those settings next Saturday...the 911 is the weekend car.

[thabaer]

Originally posted by chuckw951
Any product that could cause "fatal electrocution" has to be cool.

muhahahahahah.....what's that old adage about shooting the FUD-makers

Tempting, tho'... matching up the ignition w/ the EFI conversion makes me think about not re-installing my CIS.