Has anyone here put a turbo on a -10?

[rv6ejguy]

Originally Posted by rvbuilder2002

Another challenge that (I don't think)has not been mentioned is engine cooling.

The biggest benefit of a turbo (If you truly discount the speed benefits up high) is to help performance on high density altitude days. High density altitude days by definition are HOT days.

If The turbo provides more power at high altitude than you could produce if normally aspirated, then you will have to have the ability to cool that additional power. The air begins to get mighty thin even in the upper teens.

The few people that have successfully integrate a turbo on an RV have found this to be the biggest challenge. It requires a huge amount of cowling and cooling system modification.

Given the low Vne, you wouldn't want to maintain SL power to 18 or 24K as you'd bust that speed as soon as you lowered to nose at 30 inches MAP. I'd say you'd be running closer to 22-25 inches and 2200-2300 rpm.

If you can cool 260hp at SL at 170 kts. and say 25C, you can cool 182hp (70% power) at 190 KTAS and 18,000 feet at 0C. You need intercooling to keep the induction temps down and as I said before, you'll need a bigger oil cooler for sure. The extra airflow for these will add some drag of course.

Very doable but is 20 knots worth the trouble and expense?

[rocketman1988]

...and now we get to the heart of the matter...

"...Very doable but is 20 knots worth the trouble and expense?..."

That is definitely the question...

Of course what would really be cool is a couple of small jets bolted to the wings of the -10!

[burrm]

Originally Posted by rocketman1988

...and now we get to the heart of the matter...

"...Very doable but is 20 knots worth the trouble and expense?..."

That is definitely the question...

Not necessarily. In my mind at least (and presumably that of the OP), it's less about the 20 knots and more about the potential increase in climb performance and service ceiling (for example getting on top of weather, increased safety margin over mountainous terrain, crossing large bodies of water, etc).

Whether it's "worth" it or not would depend on what those gains actually are, and the cost (in terms of both time and $) to overcome some of the practical design challenges that have been mentioned such as cowling mods, cooling considerations, etc..

Does anybody know the builders/owners of that plane in the youtube videos and if they would be willing to chime in here with their building experience and real-world performance data?

[jeffwhip]

Originally Posted by smash603

That?s what I am saying, Guys run 170kts consistently.... is there a problem with targeting 195kts? Or is the margins that Vans built in not enough margin?

I think trying to target 195 TAS is a foolish plan. That is only 2.5% from VNE. I have over 18,000 hours total and have had several instances where I?ve exceeded VNE (not in a Vans RV) due to circumstances beyond my control. Winds, mountain wave, or an aircraft malfunction are just some of the ways that can cause you to exceed VNE.

If you want to go faster I would encourage you to consider another airframe. Just my $.02.

[rvbuilder2002]

Originally Posted by rv6ejguy

Given the low Vne, you wouldn't want to maintain SL power to 18 or 24K as you'd bust that speed as soon as you lowered to nose at 30 inches MAP. I'd say you'd be running closer to 22-25 inches and 2200-2300 rpm.

If you can cool 260hp at SL at 170 kts. and say 25C, you can cool 182hp (70% power) at 190 KTAS and 18,000 feet at 0C. You need intercooling to keep the induction temps down and as I said before, you'll need a bigger oil cooler for sure. The extra airflow for these will add some drag of course.

Very doable but is 20 knots worth the trouble and expense?

I defer to your experience Ross, so maybe you are right. I was just quoting from the experience that a couple of RV modifiers have had.
They could easily cool down low but as soon as the got in the upper teens / lower 20's and tried to operate at normal max continuous power, they couldn't keep the temps under control until they did some rather radical (and ugly in my opinion) adjustments to the cowl cooling air inlet and outlet sizes.

[rongawer]

Originally Posted by rvbuilder2002

Another challenge that (I don't think)has not been mentioned is engine cooling.

The biggest benefit of a turbo (If you truly discount the speed benefits up high) is to help performance on high density altitude days. High density altitude days by definition are HOT days.

If The turbo provides more power at high altitude than you could produce if normally aspirated, then you will have to have the ability to cool that additional power. The air begins to get mighty thin even in the upper teens.

The few people that have successfully integrate a turbo on an RV have found this to be the biggest challenge. It requires a huge amount of cowling and cooling system modification.

That's only true for developing more power than 260hp with a turbo. Maybe the OP only wants to maintain 260 in the climb well into the teens. I personally am targeting 18,000 as a max operating altitude, simply because I hate wearing a mask...but others may desire higher.

If the cowl can handle 260 hp NA, it can handle 260 hp turbo'd - as in turbo-normalizing. Going beyond 260, yes, then you need modified air flow.

However, let's say you want to use a 2.0L engine that normally produces 200 hp, but with a turbo to develops 260 hp. Let's say you would cruise at about a 200 hp setting, the airflow of the Van's cowl would be fine in this installation. It's a turbocharged installation, but the heat developed would be no more than the total sum developed by 260 hp.

[rvbuilder2002]

Originally Posted by rongawer

That's only true for developing more power than 260hp with a turbo. Maybe the OP only wants to maintain 260 in the climb well into the teens. I personally am targeting 18,000 as a max operating altitude, simply because I hate wearing a mask...but others may desire higher.

If the cowl can handle 260 hp NA, it can handle 260 hp turbo'd - as in turbo-normalizing. Going beyond 260, yes, then you need modified air flow.

However, let's say you want to use a 2.0L engine that normally produces 200 hp, but with a turbo to develops 260 hp. Let's say you would cruise at about a 200 hp setting, the airflow of the Van's cowl would be fine in this installation. It's a turbocharged installation, but the heat developed would be no more than the total sum developed by 260 hp.

In theory that may be correct but in practice by those that have actually done it, it hasn't worked that way.

Cooling the engine at 8000 ft while producing 75% power and cooling it at 18000 while still producing 75% power are two totally different situations.

[rv6ejguy]

Scott is correct. Cooling becomes more challenging as air density falls with altitude. Remember cooling is about mass flow. Cooling in the climb, where power is high and mass flow is low is most challenging.

Wanting to run more than 30 inches up high may need some mods on a -10.

In an atmo engine, power conveniently drops off as altitude increases which lowers the heat load. This doesn't happen on a normalized engine or boosted one. Might be ok on cool or cold days but not on over standard ones once you get above 10,000 or so.

It comes down a lot on how much power you want to push, what altitude and the OAT.

I don't think it's realistic to think you'll be able to run 35 inches at 18,000 feet without cooling mods and you couldn't use that much MAP in a -10 anyway up there as you'd be way over Vne.

As far as increased climb capability, yes that's a benefit but you may find you have to keep the nose lowered to keep the CHTs down so the ROC may be little better with the turbo as with an atmo engine.

[rongawer]

Think liquid cooling to solve CHT issues.

Regardless of your altitude, the heat load from a fixed horsepower is the same; yes, thinner air requires more flow to obtain the same mass flow rate. And yes, you need additional air flow for an intercooler. But these are not reasons to not use a turbo, they're just implementations you need to engineer to use one.

I'm solidly in the camp that turbos are a good thing to improve engine efficiency and maintain power through the climb and into cruise.

There are many good turbo-charged aircraft out there, turbo-normalized too, both certified and experimental. It's just a matter of what your goals are and the effort you're willing to apply to achieve them.

Very doable on a -10.

[rv6ejguy]

Yes very doable if you address all these areas.

Liquid cooling solves many of these issues but that's not applicable to a Lyc 540. Not sure if the Cool Jugs are still being made?

At Reno they're pushing insane hp numbers but lots of ADI and spray bar water, lower altitudes and much higher speeds (mass flow) to compensate. CHTs are also running higher than what you'd want on your cross country plane.

I'm all for seeing some more people try a turbo installation on a -10.