Scott Will

Scott Will

Well Known Member
Due to space constraints and the fact that my engine builder already put the DB connectors on, is it OK to mount the Lightspeed Plasma box on the firewall and if so, is a cover really necessary? I seem to recall seeing pics of people's Lightspeeds mounted on the firewall without any special support or cover.

Any thoughts or recommendations? I appreciate it.
 
Scott,

I too received my aerosport engine with both ends of the crank sensor wires already terminated. I talked to the Lightspeed guy (Klaus?) and he was adament about not mounting the box unprotected on the firewall. He said the sensor wires could not run along with any "noisy" wires like alternator, solenoid, or P-lead etc. So instead of cutting a huge hole in the firewall just for the sensor wires I unsoldered the d-sub connector passed it through a small hole and reterminated with crimp sockets and a new connector. I haven't run it yet but should work fine. Also with the crimp connector you can un-pin it should the need arise.

Paul Danclovic
Carver, Minnesota
Painting 8A
 
Ran my duals LSE's on the firewall in the engine compartment for 1100+hours my 6 with no troubles.
 
LASAR Controller on FW

I mounted my LASAR control box (electronics) on the firewall with no problem. It is covered and the harness wiring is independently routed from all other wiring. The PWB and components probably don't know that it says LASAR on the outside.

Bob Axsom
 
backing plate?

Thanks guys!

Did you mount it directly on the hot side of the firewall with or without a backing/reinforcing plate?
 
My Installation

I mounted platenuts on two pieces of aluminum angle and riveted the the aluminum angles with the 3/16" platenuts to the back side of the firewall. The box is then installed with four AN3 bolts and AN960-3 washers. It is very sturdy. You really have to plan ahead if you go this way because of the items on the back of the firewall that will interfere if you don't locate everything properly.

Bob Axsom

lasarphoto0jv.jpg
 
Lse

I mounted my dual LSE's on the fire wall with platenuts. I was worried about over heating! I also have GRT EIS and EFIS system so I setup a temp sensor at the LSE location. Summer or winter the temp runs about 20f deg. higher than outside air temp.

Frank N821BF
 
Outside of putting the brain box on the firewall, does anyone have feedback on what other locations might be suitable on the RV-7? I'm thinking on the inside of the firewall above the rudder pedals, but I would be interested in pictures or comments on what others have done.

THnaks,
Scot
7A Finishing
 
Scott Will said:
Did you mount it directly on the hot side of the firewall with or without a backing/reinforcing plate?
Click to expand...
My Lasar is mounted using four 1/4" bolts and floating nutplates mounted to .063 reinforcing strips. I used a type of cork material from NAPA between the unit and the firewall to help isolate it a bit. A phone conversation with Unison's technical people said my planned installation was perfectly acceptable. Since the photo was taken, I ran a few inches of blast tube from the back baffle to it just for grins. Anyway, the LASAR has performed as advertised for 200 hours now. Still, I would contact Lightspeed and get their assurances before attempting the same type of installation with their product.

constructiondetails0952ga7.jpg
 
Scott, I would strongly second what others have posted - do not put the Lightspeed controller on the forward side of the firewall. It is absolutely not weatherproofed like the Lasar system controller. Even the Lasar controllers are affected by water (I helped someone dry their Lasar controller out after a rainstorm).

Of course, you may run them on the forward side and get away with it as others have, but the designer of the system recommends not doing it. Reliability is all about probabilities - more heat = less reliability. Moisture will also be a problem, and it may not manifest itself on startup.
 
Scott I did what Dan did (post #2)

I have been running now for over 45 hours, no problem. The box is mounted on the rib the runs fore and aft under the front top skin.

Kent
 
I built a shelf

I just finished trial fitting the shelf I built for my LSE install yesterday. I sized it large enough for 2 LSE II's even though I will only run a single LSE initially. Getting the length right took a bit of work because if you go all the way to the sub-panel won't clear the lip of the sub-panel when it swings down
,
lsemountxv7.jpg
 
thanks guys. I was thinking about putting on it in inside of the firewall (opposite where the Lasar picture is shown). I should be able to get it in and out via my access panels from there as well.

Scott
 
Wow I cant believe someone dug up this old thread. Just wanted to chime in now that I have come full circle ... my Lightspeed being mounted on the firewall is just fine. Been performing flawlessly for 67 hours now. You'll be happy with this unit!
 
Scott, with all due respect, flying for 67 hours does not mean that the Lightspeed controller likes being on the forward side of the firewall. Has your plane sat out in a good rain yet?
 
Working in the airline business, I know what reliability should be. I agree 67 hours is nothing. But my friends have had theirs on the firewall for over a thousand hours no problems. I just wanted to post after seeing this thing ressurected and I was the original poster.
 
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