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Hello everyone. This is my first post to this forum though I am a regular on the other Diamond forum. My home field is a grass strip not far from KVUO.

I wanted to write and update you on a little project that I have been privileged to be involved with. Namely - Supercharging a DA40. Last November I delivered 40.649 to Rod the owner of Forced Aeromotive Technologies (http://www.forcedaeromotive.com/) or FAT for short. The goal is to supercharge my DA40 then for FAT to create an STC for everyone to use. My interest is strictly to better the airplane (specifically mine) while FAT's interest is to add a new product to their business. I'm not getting compensated for "advertising" but do it because the STC will only be applied for if there is encough interest to make it pay for it's self. In the mean time my airplane will be under an experimental "market survey" certificate until either I get a one time STC or the final STC is approved.

So here is where the project currently stands. The plane has been ground run and was able to produce over 30" MAP even though the field elevation was 6,000' (Denver, Co area). A newer pulley has since been installed which should provide even more boost. The design goal is to achieve sea level power upto between 7 & 9,000'.

The joke is, even though they use the letters FAT it can be said that this installation is anything but fat. So far it only weights 18.4 lbs and is expected to grow less than 1 lb by the time it is all finished. That means that those of you with the 20 lbs of ballast should be able to remove the ballast and install the supercharger. Trading dead weight for something really useful.

The supercharger being pulley driven has one failure mode. Which would be the supercharger failing to provide boost because of a broken belt or other event. If this were to happen then the aircraft, so I am told, just reverts to normally aspirated minus about 0.2" MAP.

Management of the boost will be completely the pilot's responsibility. With this system the pilot must push in the throttle so that the MAP reads a no more than a maximum allowed value. I don't yet know what that limit is. Should be someplace between 29 & 30". What ever was used when the engine was certified to 180hp.

The FAA is scheduled to sign off the paperwork on Tuesday 22 MAR 11. Then it will be ready for the first flight tests. I will post flight data on currusreports and make it public once FAT gets the file to me.

The installation requires a bump in the cowl. You can see attached photos of the work being done on the cowl and a very early mock-up of the installation (which has since changed considerably) to give you an idea of what is being done.

Welcome to DAN, Brock! I've been following your thread on DAA with a great deal of interest. I was hoping you'd post some updates over here as well since I don't check DAA nearly as often as this site.

The FAT install progress is very interesting to me since I fly in the same environment as you (we are based out of KHIO) and thus would really like to get some better performance above FL100. I've done two round trips back to the Midwest, and flying over the Rockies at max weight just isn't much fun with the reduced performance we get above 12k.

Note that you can post your flight logs to the reports section on this site instead of (or in addition to) cirrusreports. I believe the reports section here has many of the same capabilities as the cirrus site and is continually getting improvements.

Welcome here Brock, looking forward to your updates!
Has Rod set the final price for the production version and STC?

Best regards from mountaineous Switzerland

A friend of mine is to test fly this 40 in the next week or two. I will let you know what he thinks.

What reduced performance?? I get 143 true easy at 14K over the rockies. No problem. I do it all the time. Climbing up to that point is another matter.

Before anyone gets too caught up in the potential gains from a supercharger I suggest reading the following - http://www.vansaircraft.com/pdf/hp_limts.pdf

Erik S

Erik S. wrote:What reduced performance?? I get 143 true easy at 14K over the rockies. No problem. I do it all the time. Climbing up to that point is another matter.

Climb rate and the ability to hold altitude in the presence of turbulence (near max weight) is what's notably missing above 12k. Airspeed (TAS) is fine up there, though I'd always love to have more.

I've read the Van's article before and found it enlightening. It's been debated as to where the flutter limit (based on TAS) is in a DA-40, but it's not documented anywhere as far as I can tell. What is clear is that the documented Vne is based on IAS which implies (at least to me) that below 16,400' you won't reach the flutter limit if you stay under 178 KIAS. That said, I'd be ecstatic to have to live with only 178 KTAS if I could have 600fpm climb rate at altitude

I am looking forward to hearing what your friend and Brock think about the system after it's installed. Measured performance and practical limitations of the system in the real world is what really matters in the end.

Eric, I agree with Chris. It's not all about the speed. Above 10,000' climb rate for me was marginal. What I mean by marginal was that keeping 500 fpm (a magical IFR #) is hard to do. I've had problems with climb rate mostly because I'm pig-headed about staying below 400 cht in climb and 380 in cruise.

As it turns out though, Rod seems to have found my problem (or a problem). He said I had a significant baffle gap in the order of 1". So Chris you might want to have some one hold a bright light in the cowl from underneath and look for gaps through the air inlets.

I do have a theory about heat. We will know if a few days if it's correct. That is even though the DA40-S will have more power in thinner air, being able to climb at a faster IAS will work the cooling system better. Seems my DA40 cools (used to) best at 110 IAS.

Hearsay. It's just hearsay but Rod thinks the DA40 will gain more performance than the Sirus did. He says this based upon wing design. BTW - The sirus gained 15 KIAS I believe. We are likely to gain an even 500 fpm above 7000'.

Brock,

Welcome to DAN.

The picture links were linked to a password protected site. You can see them while you have the DAA cookie, but others who don't have the cookie will not be able to see the picture.

Just upload the pictures locally as an attachment or use links of a site everyone can reach. If you post them into the Gallery http://www.diamondaviators.net/forum/gallery, I will be able to replace the links in your post with thumbnails of the pictures you meant to post.

To upload your reports, please use our reports-section, it works the same way as the Cirrus reports site: http://www.diamondaviators.net/reports

Chris wrote:...I think you need to get to ten posts in order to create a signature. There is a "Ranks" thread in the Announcement section which describes what abilities you are granted as you make more posts.

OK, finally put on my reading glasses and found the "Browse..." button. Here are the images that belong on the first post. Hmmm, seems to have a limit of two images. Have you found this to be true? I sense the need for a dedicated web page for this project.

Seems like a pretty minor cowl bump. Pretty impressive that they were able to fit everything in there without a more significant modification to the cowling.

Looks like Brock has broken 150 KTAS at FL120...

http://cirrusreports.com/flights/N8QQ/

the bad news is the fuel flow. 13 GPH...