No Brainer
jwyoungjr said:
I would like to replace one mag on my rv-6a /0-360 /cs prop with either a light speed or a p-mag. Now that there is more experience with the p-mag, would you give me your take of performance, gph, and installation. Thank you
What difference would it make if some one posted they got 3% better economy verses 4%, or picked up 2 mph verses 3 mph. Would that make a difference to your decision? Have you decided on the P-mag already or are you on the fence about EI at all?
(I am surprised no one has answered you but than again it may be because its difficult to pin down hard numbers. I don't have P/E-mag spacific experience, but have used electronic ignition and followed the P/E mag folks developments. I guess when I read your post/question I am wondering why you need to switch from a magneto in the first place. I am all for EI. I think a more important question than performance and economy gain is reliability, installation, operation and support. All EI will give you HP gain and lower fuel burn. So to answer your question I'll give you my rant and rave on performance claims first. Last I give my take on the differnt brands, read at your own risk. 
In the end may be no EI is best for you. Why have EI? If you don't fly a lot or long distance much, its not going to make economic sense if you already have working magnetos. You have to save lots of gas to pay for an EI.)
First if you have the time plow thru the CAFE FOUNDATION ORG research articles, find the 3 part article comparing an Electroair EI to Magnetos.
THESE ARE THE HARD NUMBERS you are looking for, but it took The Cafe Foundation to publish a 3 part article and LOTS of graphs to explain. They also go in single EI and dual EI combos.
The Electroair and P/E-mag should give very similar performance since they use the same technology. The P/E-mag might make some compromises or concessions to fit their unit in that small package, but it should be close.
(OPINON ALERT: I don't think the P/Emag is a "Performance EI", but the differences are very small between EI brands. Even P/E-mag states that absolute performance was not the goal. I am reading between the lines but that means they made a concession to get the unit into a stand alone compact package (which is awesome). Also P/Emag does not publish technical specs like Lightspeed. Bottom line, between EI and traditional magnetos there is a clear difference.)
http://www.cafefoundation.org/research.htm
There are times you burn MORE fuel with EI, because it allows you to burn more fuel efficiently. Granted you are rewarded with more power and thus airspeed. It makes sense, you make more power you will go faster, but nothing is FREE, you will burn more fuel. Now if you want to save fuel, EI does that as well. To get better MPG with EI depends in part on the pilot and how you fly. In general most of the economy gain with EI is by flying high (below 75% power). EI really shines in burning a lean mixture which is hard to do, but EI does it well, which allows you to run leaner and waste less fuel (oversimplified but makes point).
Bottom line is read the above research by cafe foundation OR believe me ANY electronic ignition on the market, Lasar, Lightspeed, P/E-mag or Electroair WILL all give you better performance/economy over all. Is it a big deal if is 3% verses 4%? Its ALL GOOD.
Exact numbers are hard to quantify and mean little out of context (ie how they actually fly). People that putt-putt around down low benifit less, where a fast RV-6 with 180hp c/s prop, going places, will benifit a lot. Even if you don't save HUGE fuel or go WAY faster there are other benefits that are not perf/econ numbers..........................
Here is my take:
-An EI of any brand is a no is a NO brainer, get it.
-Most benifit comes from the replacing the first mag.
-Round ball park numbers expect better overall power (2%-6%)
-Round ball park numbers expect better fuel economy in cruise (**caveat**)
-EI should be very reliable and cost of owner ship lower than typ Magneto
-It will give smoother operations
-Less maintenance
I guarantee from all I have read and from my own experience (but not with P-mag), you get a little more power and (potentially) better gas milage. I say potentially because there is no sure thing in fuel economy. The pilots hand on the throttle and mixture play an important part in economy.
Caveat:
At 75% power or less, using optimal leaning, a EI should return about 2% to 5% and better overall economy. The second EI will give an additional 1% to 2%. Max efficency in cruise should be 6%-10% in some (not all) flight conditions. Lightspeed says they see up to 15% better econ with dual Plasma ignition. I believe them, but it takes effort and tailored flying (real high) to achieve this.
You will not see this at the pumps. Also when you talk % economy most gain comes at LOW power setting when FF is already at less, 6% may only be 1/2 GPH. If you only fly around with your hair on fire down in the weeds and never lean, than no EI will help.
As far as power, its hard to measure a few HP and top speed, but LASAR claims you see as much as 6% hp. This increase is above 8,000 feet, when the engine is at lower percent power (68% to 72%). At 12,000 feet they claim 12% more power!
That illustrates the point, to get the best economy advantage with EI you need to fly higher. So performance numbers from someone means little since they can vary from nothing to 12%. The point is there are overall benifits in many areas.
Decision:
It makes sense to get an EI, but than its a GRAND or MORE! Magnetos work just fine. They do. How much fuel do you have to save to pay for EI? With EI you are running spark plugs with HUGE gaps (way bigger than a magneto could fire), because the ignition can fire at those gaps. Your resultant spark is VERY hot. Next is duration. The sparks are FAT and last for a longer duration/crank rotation. Last timing's NOT fixed. It advances at lower power automatically. Magnetos are fixed at 25 degrees BTDC, but works pretty damn well, but not great. If cars drove around with fixed 25 magnetos they would get 2 miles to the gallon. However a plane operates in a very narrow RPM and power band 90% of the time, so 25 degrees is a good compromise, working surprisingly well.
What Brand:
The question is what EI is better. It seems you are attracted to the P-mag and made that choice already. Good choice. I don't have one but it looks like a winner. I noticed they just went thru a major revision of their design, all for the better. The decision of brand is more about features, fit, form and function, than performance for most.
Lightspeed: From pure performance and performance minded features the Lightspeed is hands down winner in my book. It is the only CDI ignition and will give better performance and operate at a lower voltage. Down side, if you want to think of it as a CON, is the separate coil/box and it cost more. However if PURE performance and/or economy is the goal, plus the added features (RPM/MAP and Cockpit timing adjust display) appeal to you, than its the way to go. Here is a page on their site that gives some perf and econ claims:
http://www.lightspeedengineering.com/Products/DualSystems.htm
P/E-mag is the winner of easiest to install. Plus its the only self powered design. The thing I DON'T like about the P/E-mag was the odd computer connectors they used. I don't see those as being suitable for aircraft engine compartments. They have revised the connector design. It's better but still not crazy about it. MIL spec electrical coupling connectors are heavy duty but expensive. No doubt they made a compromise. They also had little deicate dip swithces but got rid of those. I have not heard of major problems anyway. They don't make performance or econ claims.
There are no published specs: spark intensity, duration and total advance like lightspeed does? Only from the fact the coil package is smaller and drives 4 plugs VS. 2 plugs, I guess it could have a little less ZAP. I could be totally wrong and don't think its a huge deal.
Electroair uses same technology with the P/E-mag. They both use INDUCTIVE automotive style coils, which works well and is a lower cost technology. The separate brain box and hall effect triggers may appeal to many. I think having the electronics in a cool location, not shaking, is a good thing, however it adds wiring that P/E-mag does not need. Electroair has some IMO inflated economy claims from min 10% to 30%. Also they need to come down in price. They are the most expensive.
LASAR: I don't care for it; however if you have a certified plane its the only game in town. The LASAR falls back on the built-in magneto if the EI part fails, which is the negative of the design for me. No doubt that was the best and easiest way to get it certified. However, I don't want to carry around a completed set of magnetos to back up the EI. For some reason folks seem to have more CHT problems with LASAR? That's a different thread, but I have seen bargain deals for them on eBay. Interesting, look at there site for there claims. It should give you an idea of what you can expect from most EI's. I do think the LASAR give good performance.
http://www.unisonindustries.com/products/lasar_performance_gains/lasar_perform_gains_eight.html
http://www.unisonindustries.com/products/lasar_performance_gains/lasar_perform_gains_seven.html
Good luck, George
