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Last Subie Flight of 2007

R

rv6ejguy

Well Known Member
I took my turbo Subie 6A for a final blast today before the annual comes due on the 28th. I was solo with about 15 gallons of fuel, OAT 2C. Using 4600 rpm and 38 inches, I was airborne after a 8 second ground roll into a 10 knot wind (not holding it on the brakes). I was at circuit altitude (5000MSL) 44 seconds after brake release climbing at 85 KIAS using 4800 rpm and 35 inches.

I guess it was pretty impressive from the ground. The tower asked me if this was the turbocharged one, we have some car and airplane guys up here today. Yep I replied, 2000 fpm. Yee Haa. Sounding gooood!:):cool:

VZX, turn crosswind at your discretion. You are #1. Roger.

Not bad for a 134 cubic inch car engine.
 
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Only 2000fpm?

And there was me thinking my IO360 was old fashioned...Guess 2600fpm is not bad either.....:)

Than again I live at 247'MSL

Frank
 
You got me I think. :(

That translates into about 2160fpm still at 5000 MSL. Yee haa

Gotta love RVs whatever powers 'em.:)

We have to give those poor controllers something interesting to watch besides 172s.

Merry Christmas guys and gals on VAF. Fly safe in oh8.:D
 
Cool report, Ross.

That turbo does make a difference. I just don't trust the belt and won't have one so it takes me about twice the time to get up there starting with 29 inches.
(or maybe you don't have a belt but a true turbo charger with exhaust driven compressor)
 
We can do our inspections any time not exceeding 364 days up here. My annual is due on the 28th and the weather forecast did not look good so I did it early, especially with Christmas here.

Yeah David, I have a turbocharger so no belts to worry about. Never been a big fan of superchargers, especially non centrifugal types. Anything a blower can do, a turbo can do better on an airplane.:D It is very nice at altitude as the climb rate pretty much stays right there.

David, I feel like you and me are the only guys flying Subie's regularly here on VAF. Any others want to pipe up?
 
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Auto engines will never work!
Liquid cooled engines will never work!
The earth is flat!
Hopefully I will be joining you guys soon! Instead of the Chevy vs Ford battle we can have the chevy vs. Sube battle!
I might take the Tiger out today for my last flight of the year!
Have a Merry Christmas and a happy New Year!
 
Adventures with an EJ25 9A

Hi Ross

I have 110 hrs on an NSI Subaru 9A in Australia. Had a bit of fun about a month ago when things went wrong about 7 NM off the coast of Flinders Island in Bass Strait (famous for ship wrecks).

The NSI motor is a 2.5 block with 2.2 SOHC heads and modified cams. A large horizontal radiator (fed by ducts on the inside of the lower cowl), header tank and oil/water heat exchanger are positioned behind the engine. Unfortunately mine was one of a couple of engines with mismatched cams. Cams designed for a friction rocker arm were supplied with engines with roller arms and there is a 3? difference in the keyway position (as well as some rollers not being centered over their lobes). The result was a 50 psi difference between cranking compression of the 1 & 3 and 2 & 4 cylinder banks. The advice from NSI was that this would not matter when the engine was running but I think that it may have led to my engine failure which resulted from the engine making metal and also possibly a MAP sensor failure.

I had climbed to 8,500' for the trip home from the island and had just reduced power by coarsening pitch to slow the engine to 4,500 rpm and set the AP when I had a few "misses" which rapidly became worse. Switched to the backup ECU and fuel system with no result so turned back to the island and pulled the throttle. The engine quit but because the NSI gearbox has a sprague clutch the prop kept spinning so unless you looked at the tacho it felt perfectly normal.

The plane glides well - say 1.8 NM per 1000' at 90 KIAS so it was easy to make land but I had to dive thru a smallish hole in the cloud about a mile abeam the strip and was a bit limited by the surrounding mountains from making a wide approach so had way too much speed over the threshold - about 110 KIAS. The strip (thankfully) was 4,000' but downhill and I was beginning to wonder 2/3 rds of the way along but managed to pull up OK at the end.

I have brought the FWF assembly home and replaced the NSI engine with one from MPS which is essentially a straight SOHC EJ25 Subaru. The Motec ECUs were fuel mapped four days ago using the prop in reverse pitch to generate about 70% power and the data logging function with O2 sensor for tuning. Looks to be running really well but will know for sure when I re-install everything and start flying again.

The MPS engine is about 12 lbs heavier and 1.5" wider than the NSI but, with a bit of work, should fit OK. After flying a Subaru I don't really want to go back to a Lyc.

Rupert Clarke
 
Glad you made it back to the runway Rupert. I think you are far better off with stock Sube internals. Those Motec ECUs are pricey but nice!
 
Thanks David & Ross.

Will report on performance when I return. The NSI motor dynoed at 160 hp @ 5,800 rpm at the prop flange and was good for 155 KTAS at 8,500.

I think that a SOHC EJ25 is meant to develop 170 hp but no doubt there will be losses so hopefully performance will be similar.

There is a fair bit of weight in my installation:
Bare engine 195 lbs
Engine in FWF assembly including oils, gearbox & coolant 379 lbs
Exhaust system 18.3 lbs
Prop & spinner 30 lbs

I am thinking of going to integral coil/plugs to get rid of the two heavy Electromotive coil packs. The other heavy item is the two radiator fans but at the moment they are helpful for ground running. I intend to improve my cowl outlet set up so might be able to ditch them also.

How are you going with the cooling for the 10 Ross ?

Rupert
 
New Subaru 3.6 liter

Ross,

What do you think about the new 3.6 liter subaru engine? Same dimensions as the 3.0 but with an improved cooling system. Maybe weight is the same too. Sounds like a better mousetrap down the road. Just needs a turbo and after market fuel injection. Any thoughts?
 
On the -10 I have a ventral radiator in a dedicated duct with controllable exit door like a Hawker Hurricane. I also have a cowling mounted barrel heat exchanger which can either divert hot air overboard for extra engine cooling or into the cabin for heat.

On the new 3.6, I think this finally has enough displacement to do the job in atmo form to compare with Lyco 360s turning reasonable rpms. With forged pistons and turbos, this would be very competitive with an IO-540.

All EJ/ EG/ EZ Subes have well designed internal cooling systems- the best I've seen on any engine in fact. Fuji went to great pains to make this right. We just need to get rid of the coolant heat efficiently with properly designed radiator systems. Mine runs very cool now in the -6A. I think I finally get it.
 
Currently flying Subarus

I have been flying my RV9A N462BD since it was signed off in June. I have an Eggenfellner 2.5 SOHC naturally aspirated with some minor mods- a mild port job on the heads, three angle valve seats, and a ram air induction with a K&N filter. I currently have 125 hours on it. I have been using it to commute to my job in Seattle from my home near Spokane, but the continuing series of storms moving across the area has put a crimp on that. I managed after two tries to keep my home grass airstrip plowed clear long enough to get the plane home Dec. 24th. I am going to park it for a month or so to install the Gen. 3 gearbox and install the main gear fairings.
I have been happy with the performance so far. At 8,000' I get 140 knots at 2,400 prop RPM with the main wheels and attach brackets hanging out in the wind. My goal at the start was a 150 KTAS cruise speed, so I'm almost there. Climb performance is very good. I timed a climb from sea level at BFI to 11,000' at full gross (mine is 1,800#) in twelve minutes eighteen seconds at ninety knots. Not O-360 territory but still pretty good compared to the Cessnas I used to fly. I think I'll get a couple hundred additional FPM from the 2.02 ratio gearbox and maybe a knot or two in speed. I think these four cylinder engines are a perfect match for the RV9 and with a little more massaging I think I'll end up with very similar performance to the O-320 Lycomings.
Bob House
 
Thanks Bob, those are pretty darn good numbers for a 2.5 at 1800 lbs.

What prop do you have?

I too think the 2.5 is a lighter, better match for the RV9 than the EZ30. Too bad they are not being offered anymore.

What is your empty weight?
 
Currently flying Subarus

I have a MTV-7-C prop that I bought from Eggenfellner Aircraft. The only drawback to it is that it doesn't make any additional thrust above 2,500 prop RPM. Running it at the rated 2700 prop RPM gets no additional FPM in climb. That may change with the 2.02 gearbox and 400 more engine RPM. The theory is that more RPM & therefore power will keep the prop pitch in a more efficient range. This engine runs quite happily and very smoothly at higher revs.
My empty weight came in at 1,170# minus the wheel pants, with a full IFR panel, Aero Classics interior, and lots of soundproofing. I installed my Super Trap muffler just aft of the rear baggage bulkhead in an effort to reduce noise, but then discovered as have others that simply installing a tailpipe with a downward bend is more effective. I am going to move the muffler forward and save the weight of 5' of exhaust pipe I have hung under the fuse now. I am going to move both batteries from just aft of the firewall to just aft of the baggage bulkhead. The plane flies better with a more aft CG and I might gain a little speed. I'll weigh the plane again when I finish my mods and post the results.

Bob House
 
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