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Today I ran some tests at 9500 and 10500 with the same results - Better performance with the mags only.  I won't go into that detail because there is better information.  To wit:

 

Today I talked to one of the LASAR designer/developer personnel with the following results:

 

1. There can be a rare failure mode where switching relays just outside the mags chatter or fuse.  This causes a condition where both the mags and the controller are trying to mess with the spark at the same time and this does result in a symptom of the mags-only operation always performing better than the LASAR.  With both trying to operate, the spark is weak.

 

2.  After mag exposure to very high heat, there may be a "distributor" function breakdown in a mag.  Note that about 15 hours were flown on my airplane during which, for some period of that time, the #4 exhaust pipe was separated from the head by about one inch.

 

3. There is not much advance occurring at high rpm (say 2700 Vs 2400).  Thus, I should not expect much improvement at max high power.

 

4. Above about 27" MAP, the engine baseline timing is used (320 = 25 degrees BTDC). There is no attempt to retard timing at takeoff power.

 

5. The software is for certified standard engines.  It may not work as well in performance modified engines -- high compression pistons, effective ram air, etc.

 

6. Not all LASAR failures show up in diagnostic codes when a laptop is connected.

 

After our conversation, I hooked up my laptop and attempted to start the engine and see if there was a LASAR diagnostic code.  The first problem was that it took me 10 minutes to get it started since it wasn't switching to LASAR-Start mode (indicated by panel light) -- finally, after a rough start, it wouldn't stay in LASAR mode, ergo no codes available.  A further call seemed to indicate that problems 1 and/or 2 noted above were occurring and probably that the special mags needed replacing.  Luckily, this Unison location is in Rockford, a 1.5 hour drive away, and tomorrow I will pick up two new mags.

 

More info in a few days

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A week has elapsed and now for an update:

 

First of all, I have received exemplary support from Unison.  Not only thru numerous phone calls but because of my time constraints and the difficulty with starting, Unison also supplied me with another controller and 2 slick mags in case the LASAR problems were not resolved before the Cup Race.  I have Harry Fenton to thank for helping me thru this even though he was taking some vacation days.  I am now operating on the waranteed replacement LASAR equipment with the following preliminary results, observations and future actions.

 

A.  The old LASAR mags will receive a post mortem after AirVenture and the possible cause of their failure will be reported here.  Right now, #1 above seems to be the likely explanation.  With the Warranty replacement LASAR mags, once again the take off run is more sprightly and the climb more energetic.  I mentioned before that wouldn't try to quantify these results because of the degree of difficulty of recording data and flying the climb out.  Perhaps with a human daring enough to ride and write, I can at least get a comparison between mags and LASAR.

 

B.  As it turns out, the reason for the LASAR controller to fail enter LASAR mode for the start was that when the Unison supplied LASAR ->Laptop cable was actually hooked to a Laptop to collect data, it failed the controller.    It took a long time to figure this out since I would get a start with everything opened up, but not when buttoned up and trying to collect controller status information.  Harry said a few early cables were built incorrectly.  So, while I probably did not have to replace the controller, it is now a new one. Arrrrrgh!!  Anyway, I currently have no status or diagnostic data.  See #6 above.

 

C.  The first quickie test flight was marred by the failure of one EGT sensor, thus eliminating a precise leaning procedure.  Yesterday, I did get some preliminary numbers:

 

Using LASAR at a p-alt of 2630, D-Alt of 4100, 27*C, 28.6" MAP, 2650 RPM, 14 gph, 380 CHTs and 1300 EGTs, I saw 192 KIAS and 203 KTAS.  On switching to mags only, I saw the fuel flow drop to 13.2 gph, a slight rise in CHTs , 190 KIAS and 201 KTAS.

 

Dropping to 2510 RPM resulted in 184 KIAS and 196 KTAS on mags but 186 IAS and 197 TAS on the LASAR. 

 

Noting #3 and #4 above, this performance is probably due to the better, more consistent LASAR spark rather than spark advance.

 

On the return flight with LASAR  at 9500 feet, D-alt of 11500, 16*C, 21.9" MAP, 2660 RPM, 9.4 gph about 90*F ROP, I saw a 162 IAS and 192 TAS in smooth air.  Switching to mags only, the fuel flow increased to 9.7 gph and twiddled (don't remember why) to 10.1 gph, I saw 164 IAS with 194 TAS.

 

Harry and I will fly together after OSH so that he (and I) can get a better handle on what's happening.  Remember, I believe my LASAR's map was developed on a fixed pitch, O 320 commercially built (ugh) platform (See #5).  He freely admits that Unison has little or no data on experimental setups, what with various bells and whistles not present on spam cans.  What I am generally seeing is that if you put more wood on the fire, you go faster, given the constraints of the actions taken by the constant speed prop and it's efficiencies.

 

It is amazing on what information is developing after installing a simple switch to go between LASAR and mag modes.  I thank Unison and especially Harry for the prompt help and service.

 

BTW, if you have a 320 with a short engine mount, remote oil filter, etc, a mag change out is not a trivial experience - I think I could do it much faster now, though.

 

 

One small confounding issue: After the sensor mag was matched to TDC, it wanted to fire at about 30* BTDC.  After some adjustment to the TDC set up within specs, I could get the timing set to about 28.5* BTDC rather than the usual 25*.  Effect? I don't know yet.