PIREP on DA40 Supercharged Performance

Any DA40 related topics

Moderators: Rick, Lance Murray

User avatar
pietromarx
4 Diamonds Member
4 Diamonds Member
Posts: 433
Joined: Fri Oct 07, 2016 2:52 am
First Name: Peter
Aircraft Type: DA40
Aircraft Registration: NZZZ
Airports: KWHP
Has thanked: 29 times
Been thanked: 156 times

Re: PIREP on DA40 Supercharged Performance

Post by pietromarx »

Sounds great. In talking with FAT, they've been great and open. I'm definitely into it as I am also on the edge of the country where all the bumps are.

Question: anyone try going into (or, better yet, out of) Aspen?

Thanks


Peter
User avatar
waynemcc999
5 Diamonds Member
5 Diamonds Member
Posts: 556
Joined: Sun Jun 08, 2014 3:38 pm
First Name: Wayne
Aircraft Type: DA40
Aircraft Registration: N211WP
Airports: KSBA
Has thanked: 1502 times
Been thanked: 399 times

Re: PIREP on DA40 Supercharged Performance

Post by waynemcc999 »

Thanks, Antoine, for the idea of the IAT probe. I'll check with my shop and FAT to see how doable that might be.

I only have an indirect feel on inlet temps by what effect the SC has had -- in fact, not had -- on maintaining CHTs. Before and after the SC install, I maintain climb CHTs <400 degF and cruise CHTs <375 degF. Both before and after the SC, at say 7000' DA I run -15 to -40 LOP, and at 10,000'+ DA I'm able to run closer to peak, in all cases with CHTs <375 degF.

Happy 2020!
Wayne
Wayne McClelland
PPL/IR, 2008 Diamond Star DA40-XLS 40.922, KSBA
Photo logs of PilotsNPaws | Flying Doctors | Angel Flight | YouTube @GeezerGeekPilot
Antoine
5 Diamonds Member
5 Diamonds Member
Posts: 2043
Joined: Fri Oct 15, 2010 11:00 pm
First Name: Antoine
Aircraft Type: OTHER
Aircraft Registration: N121AG
Airports: LSGG
Has thanked: 87 times
Been thanked: 220 times

Re: PIREP on DA40 Supercharged Performance

Post by Antoine »

That's good news Wayne. In fact, you may even be able to get away with a "cheaper" version of this idea:
If you can get your hands on a thermocouple based digital thermometer, you could stick the (very thin) thermocouple probe inside the duct between SC and engine inlet and do a single short ground test to whatever RPM you normally use in cruise, climb and take-off. .
I am guessing that the level of boost is only RPM dependent (not throttle), so as soon as you hit the target RPM, inlet air will reach its max temperature.
Then you'll know how many degrees are added to ambient. And this should be a constant for this given RPM setting.
User avatar
Ian Sage
2 Diamonds Member
2 Diamonds Member
Posts: 37
Joined: Thu Dec 13, 2018 12:29 am
First Name: Ian
Aircraft Type: OTHER
Aircraft Registration: NONE
Airports: KAPA
Has thanked: 32 times
Been thanked: 36 times

Re: PIREP on DA40 Supercharged Performance

Post by Ian Sage »

Antoine wrote: Mon Jan 13, 2020 12:23 pm Then you'll know how many degrees are added to ambient. And this should be a constant for this given RPM setting.
Antoine,

Every supercharger is bench tested prior to being serialized to ensure they function as designed. During normal operation IAT's should peak around 80°F above OAT. There are many factors that influence the temperature rise and they vary some from aircraft to aircraft but our systems produce relatively low boost numbers compared to pretty much anything else on the market. With a healthy supercharger this is the main factor that keeps the IAT's low in our systems.

While it is not a Diamond data point, the kits we produce for carbureted Cessna 182s do not produce enough heat to meet carburetor icing regulations. As a result we had to include carb heat as part of our system design to increase intake are temperatures beyond what the supercharger will produce to ensure safe operation.

Cheers,

Ian
User avatar
danno2000
3 Diamonds Member
3 Diamonds Member
Posts: 88
Joined: Thu Apr 06, 2017 4:26 pm
First Name: Dan
Aircraft Type: DA40
Aircraft Registration: N270DS
Airports: KAQW
Has thanked: 55 times
Been thanked: 75 times

Re: PIREP on DA40 Supercharged Performance

Post by danno2000 »

<i> Question: anyone try going into (or, better yet, out of) Aspen? </i>

FWIW, I flew a non-modified Diamond DA40 rental out of Centennial KAPA to Aspen KASE (via Leadville KLXV) and back during instrument training. No performance issues but density altitude was reasonable on a warm early spring day and payload was only two modest sized pilots. Can appreciate the need/wish for a performance boost in the height of summer.

best,
dan
Antoine
5 Diamonds Member
5 Diamonds Member
Posts: 2043
Joined: Fri Oct 15, 2010 11:00 pm
First Name: Antoine
Aircraft Type: OTHER
Aircraft Registration: N121AG
Airports: LSGG
Has thanked: 87 times
Been thanked: 220 times

Re: PIREP on DA40 Supercharged Performance

Post by Antoine »

Ian Sage wrote: Mon Jan 13, 2020 1:20 pm
Every supercharger is bench tested prior to being serialized to ensure they function as designed. During normal operation IAT's should peak around 80°F above OAT.
Ian thanks for your openness. I would like to re-state here that I love your product and STC, and as a former DA40 owner would have loved to have it installed.

Just for my understanding: am I correct to say that IAT increase for a given installation and RPM is relatively constant? The higher the RPM the higher the IAT?
And would this 80F IAT increase actually mean that the engine can operate normally on a 100 F day (IAT =100+80 = 180F)? My inclination would have been to treat it as a turbocharged engine on hot days (John Deakin red fin)
User avatar
Ian Sage
2 Diamonds Member
2 Diamonds Member
Posts: 37
Joined: Thu Dec 13, 2018 12:29 am
First Name: Ian
Aircraft Type: OTHER
Aircraft Registration: NONE
Airports: KAPA
Has thanked: 32 times
Been thanked: 36 times

Re: PIREP on DA40 Supercharged Performance

Post by Ian Sage »

Antoine wrote: Mon Jan 13, 2020 2:48 pm Ian thanks for your openness. . .
Antoine,

We try to be as open and forthcoming as possible. We have received some criticism in the past for not releasing "all the data" in the past but as a company with a unique product there is some proprietary data that we simply can not put on public display without putting our livelihood at risk. Beyond that constraint I am happy to answer any questions you have. Just be warned it may turn into a TL:DR wall of text.
Antoine wrote: Mon Jan 13, 2020 2:48 pm Just for my understanding: am I correct to say that IAT increase for a given installation and RPM is relatively constant? The higher the RPM the higher the IAT?
The temperature rise is influenced by a number of factors, mostly the compressor RPM which is controlled by engine RPM. So the short answer to your question is yes. Lower RPM compresses less air/power/heat, higher RPM compresses more air/power/heat. Now the longer answer. . .

In our system the second most influential factor is the position of the boost controlling mechanism. In a Cirrus we have a custom (and very expensive) controller valve positioned between the supercharger and the throttle body. It is basically an butterfly valve that monitors manifold pressure and adjusts itself constantly to prevent over boosting. In a DA-40 or 182 this is done by only opening the throttle (also a butterfly valve) part way. The reason this is impacts the IAT temperature rise is the same as the reason the supercharger impacts it. Compressing air causes it to warm up, decompressing air causes it to cool down. Lets follow a volume of air through it's life cycle using the Cirrus as an example.

Our air mass is enjoying a quiet 29.92" day at a sea level airport when suddenly it finds itself being slapped around by a propeller and sucked through an air filter. Moments later several spinning metal blades chop it up, smash it back together at 36" with an accompanying 80°F temperature rise and spit it out the end of a snail. As our air is thrust rapidly down a narrow tube it encounters a metal disk partially blocking the tube (this is the previously mentioned expensive controller valve). As the air struggles to get past the troublesome disk it decompresses back to 29.5" and cools off 20° before continuing it's journey through the tubing, past the throttle body and into the intake manifold before reaching it's unfortunate demise inside the cylinder. The end result is a 60° rise at full RPM. As the plane gains altitude the intake air pressure goes down and the volume of air being decompressed by the valve goes down (35"-29.5, then 34"-29.5) until somewhere around 7000' the supercharger is compressing air to 29.5" and the controller valve is wide open. It is here at 7000' that you would see the full 80° OAT/IAT difference.

In a DA-40 that decompression of the air would happen at the throttle. If you wanted to duplicate our testing you would want to measure both the air between the supercharger and the throttle body, then the air temperature between the throttle body and the intake valve. Due to the shorter ductwork between the supercharger and the throttle it won't be the full 20° observed in the long ductwork on a Cirrus but just as compressing air warms up, decompressing air cools off.

Coming in at third in this list of OAT/IAT influences is the influence of the system components themselves. Moving the air over cool surfaces cools the air off (this is why intercoolers work) and moving air over warm surfaces warms them up. I already mentioned that the Cirrus kit has a lot of long ductwork and most of that is above the baffle where the cool air coming into the cowling can keep all that surface area cool. No, it is not as effective as an intercooler but it is impactful. Unfortunately the DA-40 throttle assembly is below the baffle in the hotter portion of the cowling. To counter the potential negative impact this could have the duct work is short and entirely silicon or composite with some heat shielding. The other major component here is the compressor itself. We've all seen pictures of turbo's that are glowing red and shrouds with "no touch" warnings on them. The air passing through those turbos receives not only the temperature rise cause by compression but also gains temperature from being passed through the super heated housing. The self lubricated superchargers in our systems run both case and oil temperatures cooler than the engine. We have video of me holding onto one during a full power ground run. It was similar to holding a hot cup of coffee. I wanted to let go because it was not comfortable but there was no risk of being burned. The cool operation of the supercharger itself helps mitigate the added heat associated with traditional exhaust driven turbo systems as well.

Ending with a fourth factor that heavily influences the temperature rise that is not unique to our system, air compression is not linear. For example, if our supercharger spinning 36000rpm can compress 30" air to 36" for a 6" increase, it may only be able to compress 18" air to 23.5" for a 5.5" increase. The ratio is a fairly flat curve but it does impact how much air is compressed and as a result, how much temperature rise.
Antoine wrote: Mon Jan 13, 2020 2:48 pm And would this 80F IAT increase actually mean that the engine can operate normally on a 100 F day (IAT =100+80 = 180F)? My inclination would have been to treat it as a turbocharged engine on hot days (John Deakin red fin)
Disclaimer first = Stay out of the Red Fin
DIsclaimer out of the way, part of our STC involves modifying the fuel servo to provide more max fuel flow. Depending on your use of the word "normally", you should be able to operate normally yes. Compared to normally aspirated there are some changes to the take off/climb/decent procedures primarily related to making sure you do not over boost the engine but you should have enough fuel to operate comfortably rich of the red fin if desired. Another fuel system part of the STC is the addition of "turbo" injectors and the associated upper deck reference system. If you are not familiar with this it bleeds air off of the supercharger to pressurize the injectors and assist with fuel atomization for smooth LOP operation at altitude.

Cheers,

Ian
User avatar
perossichi
3 Diamonds Member
3 Diamonds Member
Posts: 188
Joined: Tue Sep 18, 2018 4:05 am
First Name: Peter
Aircraft Type: DA40
Aircraft Registration: N925RH
Airports: KVNY
Has thanked: 31 times
Been thanked: 75 times

Re: PIREP on DA40 Supercharged Performance

Post by perossichi »

Could those with experience comment on what cowling mods are required to install FAT supercharger? I couldn’t find anything about this on the FAT website.

Thx!!!
Sold 2002. Powerflo, Hartzell composite two blade, 530W/430, 345 transponder.
Antoine
5 Diamonds Member
5 Diamonds Member
Posts: 2043
Joined: Fri Oct 15, 2010 11:00 pm
First Name: Antoine
Aircraft Type: OTHER
Aircraft Registration: N121AG
Airports: LSGG
Has thanked: 87 times
Been thanked: 220 times

Re: PIREP on DA40 Supercharged Performance

Post by Antoine »

Thanks again for your openness Ian. Your post fully answers my questions. I am familiar with turbocharged engines but not with mild supercharging and now I understand much better the issues, solutions and operational consequences of the STC.
Wishing you lots of success.
PS, just posted some info on EuroGA on the DA40 thread.
User avatar
Ian Sage
2 Diamonds Member
2 Diamonds Member
Posts: 37
Joined: Thu Dec 13, 2018 12:29 am
First Name: Ian
Aircraft Type: OTHER
Aircraft Registration: NONE
Airports: KAPA
Has thanked: 32 times
Been thanked: 36 times

Re: PIREP on DA40 Supercharged Performance

Post by Ian Sage »

perossichi wrote: Tue Jan 14, 2020 7:38 am Could those with experience comment on what cowling mods are required to install FAT supercharger? I couldn’t find anything about this on the FAT website.

Thx!!!
Perossichi,

The supercharger does not fit inside the factory cowling. The STC includes a composite bump/blister that is used to modify the existing cowl, providing the additional room needed to fit the supercharger. Any competent composite shop should be able to perform the work using standard practices. Once the blister is installed the cowl is repainted on the outside and fire resistant paint is applied to the inside of the cowl.

The blister itself was designed to flow with the original lines of the plane as much as possible. The most noticeable change is a more downward angle from the pilots side cowl inlet before sweep backwards. Once it is painted and installed on the plane the aesthetic change is subtle enough that most people don't notice when they walk by. Depending on the position of the propeller you almost can't see it when looking directly from the front. If the blade is out of the way the change becomes obvious when viewed head on. For comparison, here is a picture of the co-pilots side which is unchanged Image and the pilots side of the same aircraft. It is there and distinct, but it does not draw attention to itself overtly.

Cheers,

Ian
Post Reply