# Turbo Charged 2.1L Aerovee (VW) producing 100+ HP in Sonex tests

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#### dwehrly

##### Active Member
If you don't want to watch the whole video, here are a few bits of info I got out of it:
1) the 80HP Aerovee weighs about 161 lbs; 152 lbs with the Nikasil cylinders.
2) It cost $6995 (80hp) and you assemble it yourself. 3) The turbo charged version in test weighs about 185 lbs. 4) Although they avoided directly quoting price and delivery, it would seem that their target is under$10k for 2012.
5) the turbo charged prototype is somewhat quieter, runs smoother, and heat distribution is more even: CHT's & EGT's are stable and not too high (they would'nt say what the temps were.)
6) They are in the process of testing different props, but they are seeing cruise speeds at altitude that rival the Jabiru 3300 (6cyl-120hp) in the sonex aircraft.

Sounds like one sweet little 4-banger. I'm in the process of building a Waiex, and I think this engine will give outstanding performance for price & weight. It'll probably put the corvair guys on the fence too.

#### Vigilant1

##### Well-Known Member
Sonex has announced the price and specs for the Aerovee Turbo kits:
Complete kit (turbo plus enfine): $10,995 Turbo only (for those who already have an Aerovee engine):$3,995

Those fitting the turbo to their existing engines will also need to factor in the cost of a new prop.

Specs for the engine and performance for the kit installed in a Sonex (all as provided by Sonex):

 AeroVee Turbo Specifications:
Horsepower:100 hp @3400 RPM
Max. Cont. RPM (Below 5000' MSL):3200 RPM
Max. Cont. MAP:40 in HG
Oil Capacity:3 US Quarts
Weight (Dry):185 lbs
Full engine specifications found at: www.AeroConversions.com
 Sonex/AeroVee Turbo Performance:
Rate of Climb - Dual:700-1100 fpm
Rate of Climb - Solo:1000-1300 fpm
Cruise Speed @ Sea Level:135 mph TAS*
Cruise Speed @ 8,000':175 mph TAS
Max Level Flight Speed @ 8,000' (WOT):187 mph TAS
*Meets Sport Pilot Requirements

More info at their site: Sonex -- The Sport Aircraft Reality Check!
The claimed 135 MPH max cruise at SL is, ummh, something that keeps the plane within the LSA rules.

An interesting note from that site:
The AeroVee Turbo is a pull-through turbo arrangement utilizing the standard AeroVee-sized 32mm AeroInjector. As a "free-floating" system, boost is controlled only by throttle setting limited by a fixed waste gate and power still diminishes with gains in altitude, but losses are not nearly as-drastic as those with a normally-aspirated engine. This allows the cruise speed of an AeroVee Turbo in a Sonex Aircraft at-altitude to eclipse the performance of the 120hp Jabiru 3300 engine.
It will be interesting to see how these installations deal with the heat, and how the exhaust valves hold up. If it develops a good reputation over time, they could sell a lot of them. History has not been kind to companies and individuals who have tread here before, but maybe Sonex will succeed. I wish them luck, and will watch closely.

#### mcrae0104

##### Well-Known Member
HBA Supporter
Log Member
It will be interesting to see how these installations deal with the heat, and how the exhaust valves hold up. If it develops a good reputation over time, they could sell a lot of them. History has not been kind to companies and individuals who have tread here before, but maybe Sonex will succeed. I wish them luck, and will watch closely.
You're right that time will tell. I'm planning to be in the AeroVee Turbo forum on Thursday. If we learn anything that isn't already covered on their website or in the EAA webinar on the engine, I'll pass it on.

#### Pops

##### Well-Known Member
HBA Supporter
Log Member
Stock fin VW heads can just cool so much heat. Expect CHT heating problems. Revmaster make their own heads with bigger fin area that will cool better. Can also order Turbo models with provisions for a oil controlled propeller. Not a kit engine. » NEW R-2300 ENGINE
Dan

#### Rienk

##### Well-Known Member
Stock fin VW heads can just cool so much heat. Expect CHT heating problems. Revmaster make their own heads with bigger fin area that will cool better. Can also order Turbo models with provisions for a oil controlled propeller. Not a kit engine. » NEW R-2300 ENGINE
Dan
I didn't see an TC version of the RevMaster... can you provide a link?
I would love to use one just for turbo normalizing, so cooling hopefully wouldn't be an issue (with the larger fins?).

I really like that they have complete dual ignition/sparkplugs. Does anyone know if they intend to ASTM certify this engine?

#### mcrae0104

##### Well-Known Member
HBA Supporter
Log Member
Turbo question

I'm planning to be in the AeroVee Turbo forum on Thursday. If we learn anything that isn't already covered on their website or in the EAA webinar on the engine, I'll pass it on.
Since the AeroVee Turbo is a fixed wastegate and the max. power is 100hp, I would expect the power vs. altitude of this engine to look something like this:

However, AeroConversions says that at some (unspecified) altitude, it outperforms a Jabiru 3300. I spoke with Jeremy Monnett briefly after his forum, and he said that although the power diminishes with increased altitude, it does not do so as rapidly as a normally-aspirated engine. Assuming I understood him correctly, I would think that the graph looks like this...

...but that doesn't make sense to me unless the boost is gradually increased with altitude (contrary to its fixed wastegate). Can anyone educate me and point out what I'm not understanding?

#### Hot Wings

##### Grumpy Cynic
HBA Supporter
Log Member
Re: Turbo question

...but that doesn't make sense to me unless the boost is gradually increased with altitude (contrary to its fixed wastegate). Can anyone educate me and point out what I'm not understanding?
It depends on way is meant by a "fixed" waste gate. It's my understanding that the engine in question is a turbo normalized one. In this case the waste gate would be fixed to maintain sea level manifold pressure. The boost, or PSIG, would increase as altitude was gained. Manifold pressure, or PSIA, would remain constant until the altitude where the turbo ran out of its pumping ability. Then the manifold pressure would begin to decline with any further increase in altitude.

The power graph would have a horizontal line until the critical altitude was reached than it would decline directly with the further decrease in ambient pressure.

#### rv6ejguy

##### Well-Known Member
Re: Turbo question

Since the AeroVee Turbo is a fixed wastegate and the max. power is 100hp, I would expect the power vs. altitude of this engine to look something like this:

View attachment 33914

However, AeroConversions says that at some (unspecified) altitude, it outperforms a Jabiru 3300. I spoke with Jeremy Monnett briefly after his forum, and he said that although the power diminishes with increased altitude, it does not do so as rapidly as a normally-aspirated engine. Assuming I understood him correctly, I would think that the graph looks like this...

View attachment 33915
...but that doesn't make sense to me unless the boost is gradually increased with altitude (contrary to its fixed wastegate). Can anyone educate me and point out what I'm not understanding?
This is what's really called a free-floating turbo system with the fixed wastegate setting MAP at roughly 40 inches Ab at WOT at SL. The pressure ratio differential is roughly maintained with altitude increase. MAP will of course change with throttle opening and OAT along with turbine back pressure.

The Jab 3300 would make about 82-84 hp at 10,000 feet, the turbo VW around 82hp. The free floating setup involves various compromises for simplicity but is probably a good choice for the fixed pitch application and an engine with limited head cooling ability. With a conventional turbo system using a variable wastegate, you'd really need a VP prop to take full advantage of the power up high or trade off a lot of TO and climb performance with an overpitched cruise prop.

I'd expect CHT problems at high altitude with people running it hard and possible detonation issues as well without an intercooler. Valve life depends a lot on the material used for seats and valves. Might be ok if operated below 8000 feet with the MAP reduced a bit. The TAS increase at least helps offset the drop in cooling mass flow with altitude. Time will tell as others have said. This screams out for liquid cooled heads, then they'd have a neat package.

#### rv6ejguy

##### Well-Known Member
Re: Turbo question

It depends on way is meant by a "fixed" waste gate. It's my understanding that the engine in question is a turbo normalized one. In this case the waste gate would be fixed to maintain sea level manifold pressure. The boost, or PSIG, would increase as altitude was gained. Manifold pressure, or PSIA, would remain constant until the altitude where the turbo ran out of its pumping ability. Then the manifold pressure would begin to decline with any further increase in altitude.

The power graph would have a horizontal line until the critical altitude was reached than it would decline directly with the further decrease in ambient pressure.
This engine is running 40 inches Ab so it's not normalized.

The power graph is a fairly straight line but with a more shallow downslope compared to a naturally aspirated engine.

#### Hot Wings

##### Grumpy Cynic
HBA Supporter
Log Member
Re: Turbo question

This engine is running 40 inches Ab so it's not normalized.
40" sure isn't normalized. Seems like lot for a VW without H2O heads.

#### mcrae0104

##### Well-Known Member
HBA Supporter
Log Member
Re: Turbo question

This is what's really called a free-floating turbo system with the fixed wastegate setting MAP at roughly 40 inches Ab at WOT at SL. The pressure ratio differential is roughly maintained with altitude increase. MAP will of course change with throttle opening and OAT along with turbine back pressure.

The Jab 3300 would make about 82-84 hp at 10,000 feet, the turbo VW around 82hp. The free floating setup involves various compromises for simplicity but is probably a good choice for the fixed pitch application and an engine with limited head cooling ability. With a conventional turbo system using a variable wastegate, you'd really need a VP prop to take full advantage of the power up high or trade off a lot of TO and climb performance with an overpitched cruise prop.

I'd expect CHT problems at high altitude with people running it hard and possible detonation issues as well without an intercooler. Valve life depends a lot on the material used for seats and valves. Might be ok if operated below 8000 feet with the MAP reduced a bit. The TAS increase at least helps offset the drop in cooling mass flow with altitude. Time will tell as others have said. This screams out for liquid cooled heads, then they'd have a neat package.
Thank you Ross! I googled free floating turbo and turned up this helpful book (in particular, Supercharging at Sea Level, pp. 103-104). The mistake in my thinking was that the 120hp curve should have more slope than the 80hp N.A. curve. When boosted by 10" (roughly maintained with altitude increase as you point out), the curve shifts right, keeping its original, shallower slope. Therefore, the second graph is correct in concept and what Jeremy said makes sense to me now. Much appreciated.

S

#### SvingenB

Re: Turbo question

Looking at the price for the Aerovee turbo kit. It's US$11k which is € 10.4k. The engine has 100 HP at 3400 rpm. Continuous HP is 80 at some lower RPM, not sure what, but typically around 3000. The Sauer 2400 UL can run continuous at 3000 rpm and delivers 90 HP. At 80 HP the rpm is 2600-2700 rpm. Obviously the Aerovee turbo will perform better at altitude, but it can also run a larger prop due to lower rpm and has more continuous HP at low alt. The funny thing when looking at prices, the Sauer 2400 UL is € 11.5. Keeping in mind that comparing a Sauer and a Aerovee kit is like comparing a ready to run BMW and a make it yourself Ford, the price for for the turbo Aerovee is very steep. The price for US$ is record high these days, and this makes the price for US VW conversions ridiculously high compared with Sauer engines.