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  #11  
Old 06-30-2016, 06:00 PM
BD4Guy BD4Guy is offline
 
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Default Bump

Bump for this fascinating thread.!
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  #12  
Old 07-04-2016, 02:14 PM
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rv6ejguy rv6ejguy is offline
 
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Here's a photo of Dave's SDS installation along with the magic TB scoop. Inside the scoop is a tight fitting, large diameter, velocity stack which clamps to the TB snout.



Another update from Dave after some more flying:

"I have always let guys see what I’ve done if they were interested. Over the years i have just continued looking for practical applications of sound theory. Decreasing drag is more effective than increasing HP. It gets increasingly more difficult to find performance gains as you continue working. All the easy ones are already done and then even when you do something you know is sound science sometimes, it isn’t easy to prove it worked. I have made over 30 changes to my plane and some took perhaps 3-4 small changes together to be able to see any improvement.

I like the experimenting and then testing. I can already tell that the better atomization the SDS provides for the mixture at high altitude is so far superior to the old system I had, and the improvement in runway acceleration and climb is obvious, let alone the ease of operation. It just makes sense to get the maximum pwr out of the fuel you’re using. I had to call off my test yesterday when I saw the fuel leak between my legs at 17500’ but I’ll get that corrected and continue testing. (Seeping pipe plug fitting on pump module)

I’m really anxious to be able to peak each cylinder to see how far apart they are from each other at max pwr WOT and compare it to low power economy high alt cruise. As I’ve said, the CHT spread is smaller than ever before and I haven’t even been able to try tuning each cylinder yet."

Dave has done some more tests on moving the injector thermocouple to other injectors to see what differences are present. He's compiling data on that now.
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Ross Farnham, Calgary, Alberta
Turbo Subaru EJ22, Marcotte M-300, IVO, RV6A C-GVZX flying from CYBW- 417.4 hrs. on the Hobbs,
RV10 95% built- Sold 2016
http://www.sdsefi.com/aircraft.html
http://sdsefi.com/cpi.htm



Last edited by rv6ejguy : 07-04-2016 at 05:28 PM.
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  #13  
Old 07-04-2016, 05:08 PM
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Toobuilder Toobuilder is offline
 
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Ross,

Any interest from Dave to try your new direct port injectors? As much as he likes to tinker, it seems a natural upgrade to aim the nozzle discharge right at the intake valve instead of the tube mounted setup.
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  #14  
Old 07-04-2016, 05:26 PM
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rv6ejguy rv6ejguy is offline
 
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Quote:
Originally Posted by Toobuilder View Post
Ross,

Any interest from Dave to try your new direct port injectors? As much as he likes to tinker, it seems a natural upgrade to aim the nozzle discharge right at the intake valve instead of the tube mounted setup.
He hasn't said much yet about it. He spent several months getting the new engine and EFI installed. Now that it's all together, I think he wants to have everything well tested and tweaked before he heads to Reno in September. Beware other RV class entries. This thing is wicked fast.

That being said, since we do have an angle valve, top mount injector solution now, it would be interesting to have Dave test them back to back after having a good baseline with the tube mounted setup.

In race car stuff, it's been found that the injector being placed further from the port actually makes a bit more power than right in the port on most engines. Throttle response and cold starting is usually a bit worse though.
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Ross Farnham, Calgary, Alberta
Turbo Subaru EJ22, Marcotte M-300, IVO, RV6A C-GVZX flying from CYBW- 417.4 hrs. on the Hobbs,
RV10 95% built- Sold 2016
http://www.sdsefi.com/aircraft.html
http://sdsefi.com/cpi.htm


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  #15  
Old 07-04-2016, 05:29 PM
BillL BillL is offline
 
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Default Love looking under the "hood"

Like the exit chute w/side guides. I can't quite figure out the oil cooler exit? One day would be interested to see what he does under that plenum for cylinder and head shrouding and air flow management.

Thanks Ross. Thank Dave for us.
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  #16  
Old 07-04-2016, 06:07 PM
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rv6ejguy rv6ejguy is offline
 
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Dave sends me photos and test updates often. I have some more photos I can post here tomorrow if I get time, showing some different angles.

Airflow management in the cooling system is important for drag reduction and I know many people on VAF are interested in real world testing like Dave does.
Remember he's also cooling more hp than most other folks with similar sized engines.
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Ross Farnham, Calgary, Alberta
Turbo Subaru EJ22, Marcotte M-300, IVO, RV6A C-GVZX flying from CYBW- 417.4 hrs. on the Hobbs,
RV10 95% built- Sold 2016
http://www.sdsefi.com/aircraft.html
http://sdsefi.com/cpi.htm


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  #17  
Old 07-04-2016, 06:25 PM
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DanH DanH is offline
 
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Quote:
Originally Posted by rv6ejguy View Post
Here's a photo of Dave's SDS installation along with the magic TB scoop. Inside the scoop is a tight fitting, large diameter, velocity stack which clamps to the TB snout.
No magic there, just the optimization Dave talks about. I think he has been running the basic concept (a diffuser teamed with a velocity stack) quite a while. Downside is running filterless all the time.

Quote:
Originally Posted by BillL View Post
Like the exit chute w/side guides.
Dave has been doing that a long time too. He is not the only one.
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  #18  
Old 07-04-2016, 07:05 PM
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rv6ejguy rv6ejguy is offline
 
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Quote:
Originally Posted by DanH View Post
No magic there, just the optimization Dave talks about. I think he has been running the basic concept (a diffuser teamed with a velocity stack) quite a while. Downside is running filterless all the time.



Dave has been doing that a long time too. He is not the only one.
The latest iteration is much better than his last design and filter use is not important for Dave's mission or engine situation which is almost strictly about best performance possible.

I use the word "magic" loosely to describe stuff which works better than what most folks are doing in whatever field is involved. Dave's been doing this stuff a long time as you point out, so is a pioneer here in many ways. It's easy to copy, harder to innovate. Few others can match his accomplishments with an RV.
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Ross Farnham, Calgary, Alberta
Turbo Subaru EJ22, Marcotte M-300, IVO, RV6A C-GVZX flying from CYBW- 417.4 hrs. on the Hobbs,
RV10 95% built- Sold 2016
http://www.sdsefi.com/aircraft.html
http://sdsefi.com/cpi.htm



Last edited by rv6ejguy : 07-04-2016 at 07:20 PM.
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  #19  
Old 07-04-2016, 07:25 PM
BillL BillL is offline
 
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Default side chutes

Quote:
Originally Posted by DanH View Post
Dave has been doing that a long time too. He is not the only one.
Yes, I know, you have some too, Bob Axsom did some, pretty standard for good exit collection . . . . not radical though . . . . I still like 'em

I downloaded a presentation by Dave posted in a local EAA meeting from a while back ( could have been 2000) , too bad the pictures were not along with the text. It seems he added these in 1995.
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  #20  
Old 07-05-2016, 09:55 AM
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rv6ejguy rv6ejguy is offline
 
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Default Couple more photos



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Ross Farnham, Calgary, Alberta
Turbo Subaru EJ22, Marcotte M-300, IVO, RV6A C-GVZX flying from CYBW- 417.4 hrs. on the Hobbs,
RV10 95% built- Sold 2016
http://www.sdsefi.com/aircraft.html
http://sdsefi.com/cpi.htm


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