Building the new Bushbaby SAFARI

[Oupa-G]

My informants have told me that the article in the Popular Mechanics was published in the May edition. The proof reading was very factual and I hope the real article follows suit. I have no doubt because Sean who wrote the article did a lot of homework and it was very nice working with a professional of this caliber. No wonder he is the Sub editor of the magazine. They asked no pics till the host site is up and running. Tomorrow is the breakfast run at Morning Star airfield. I will have to take the Vansin as to many parts have been cannibalized from my trike so that the Bosvark could run. Sorry no pics


Cheers Oupa-G

[DarkHelmet]

Go ahead - post pics!

[Boet]

At long last, ITS BACK The B team have been busy too with the 2nd Safari.....

[Boet]

My aerie wich will also get a BeeEm enjaain, is coming together FAST. I work on it every evenig for about an hour or so. Spoke to Oupa this afternoon, and thing are starting to come alive....but rather let him tell you about it. Foudies asb Oupa??

[KFA]

Ek sien jy het toe maar besluit om die wielietjie op die regte plek te sit

[Boet]

Nope.......waiting for my nosewheel arm....... Taily gear is so I do not have to CARRY it around. Sorrreee.

[Oupa-G]

Tonight I connected some of the probes of the engine . My biggest interest at this stage are the temp of the engine. We are monitoring Cyl Head temps , EGT's . Oil temps of the core of engine the inlet of the oil cooler and the outlet. This will give a good insight to the efficiency of the whole cooling system. Also I will connect a pressure sensor for air pressure in the cowling . We will measure pressure in the pressure side of the baffle and then also the negative side under the cowling then we will see if we need to adjust the openings ,or if the eyeball engineering is correct. Enjoy the pics the focusing is still a bit of a problem on the screen.

Cheers Oupa-G

[Oupa-G]

For all the electrical boffins here is the electrical diagram of the Bosvark as drawn by our own in house Rocket scientist Otto.

The Bosvark was wired like that and it has been tested. Enjoy the puzzle.

Cheers Oupa-G

[Stephan van Tonder]

Not a huge puzzle. So the backup ECU doesn't run as a rule but you can switch to it and try to restart?. I was wondering how you were going to run redundant management systems at the same time..

[Oupa-G]

Dear Stephan

We actually run both ECU's and both plugs but only one fuel system , when you switch you run the other fuel system. So theoretically you can run the spark from one box and the fuel from the other box. The idea is that you start on the backup box it has no TPS ( throttle position switch) you do not need that for starting only for acceleration. Then you switch to the main system so on startup you have done your "mag" check. You also close down on the backup system. If you pull the circuit breaker between the alternator and the battery you isolate the two seperate systems and that is how you have full redundency. If your alternator packs up or shorts out the circuit breaker will pop and then you have the battery to work from with a full batt the load is 3 amp and a 17 amp hrs bat taking 50% usage you have about 3 hrs to land . If you can't do that it is time the gene pool gets adjusted. If the batt shorts out the system will continue on the alt the only problem is you then cannot start mid-air for that reason I use the Hawker Genesis Bat it is an absorbed glass mat bat and they are more reliable then the ordinary gel bat.
The price may be a prohibitive factor to some people. I have used these bat for years I even use them in my cars and other aeroplanes I have never had a bat failure to date and seeing there life expectancy is between 10 and 15 years they are actually cheap to run . Hope this casts some light on the subject.

Cheers Oupa-G

[Stephan van Tonder]

Ok I hear what you say but the scetch shows both systems reading TPS Redundant just doesn't read air temp. Then I'm trying to understand how the spark side is run - I assume you are running something like coilpacks fired by the management - not the usual 'magneto' system as per airplanes normally?. So each system can fire the coilpacks seperately? - can you have both ECU's 'live' to the spark side? - probably not. Unless the one system runs the one sparkplug and coilpack and the other system runs the other spark plug meaning they are always 'on' and you have the redundant 'mag' setup then which is what I think I'm seeing in the sketch.
Then Each ECU has a fully redundant Fuel system to itself - meaning you can shouldn't run them together for the fuelling side as it will then double the fuelling up?

You don't use manifold pressure at all for tuning or do you? TPS is great but doesn't actually show load on the motor the same way. I prefer to tune car engines using both but of course it's slightly different for airplane engines. I assume you also use variable timing seeing it is available in an EFI system as opposed to running 'locked' timing. Makes for easier starting for a start..
Yes I know AGM batteries - use one in my landcruiser to run the fridge..

[Oupa-G]

Stephan I should actually talk to you on the telephone because there are many small facets to take into consideration. To start of with the ECU is altitude compensated . It is very difficult to measure manifold pressure because the two throttle bodies are very short and there is a lot of pulsation but if you have the ambient pressure and the TPS position or value you have the load and that gives your position on the 3D map. Your final tuning is in the airplane for the propellor airframe combination . With a fixed pitch prop you can get away with a 2D map but as soon as you have a variable pitch you need a 3D map. As I said before we run both ECU's each driving their own coil packs actually for the main plugs we use a coilpack and for the second system coil on plugs. We only use one fuel system at a time. You can send me a personal mail with your tel# and I will explain everything in detail. We did a lot of research and have been running this dual system now for the last 6years. We have played extensively with all the scenarios. Hope this explanation helps Ps. We do use variable timing otherwise you can't start the engine we re.tard the timing to TDC and give a shower of sparks for easier starting . The timing is then adjusted according to the load


Cheers Oupa-G

[Carel]

Any chance the BMW powered trike will be sold to a previous and still financially disadvantaged person ?

[Oupa-G]

Dear Carel

My BMW trike engine is going into Boet's Explorer and my Trike is getting a new 1200 and the Bosvark is getting the 1200 110hp . I will definitely not stop trike flying. The 1100S engine in the Explorer must do lots of hours because we want to monitor it. Sorry!!!!

Cheers Oupa-G

[MICHIEL]

Baie geluk met n puik projek sover wat werklik baanbrekerswerk is.
Hoop daardie Jabi inlaat pype le daar iewers waar julle hulle gereeld sien sodat daar solank iets in die agterkoppe broei..... groete,Giel