Mailing List flyrotary@lancaironline.net Message #46518
From: Bill Bradburry <bbradburry@bellsouth.net>
Subject: RE: [FlyRotary] Re: 295cc vs 495 cc was [FlyRotary] responses to responses, not developing full power
Date: Fri, 19 Jun 2009 13:13:29 -0400
To: 'Rotary motors in aircraft' <flyrotary@lancaironline.net>

By the way, I just discovered that the fuel pressure spec for the RX-8 is over 56 lbs! See the link.

 

 http://www.myrotarycar.com/portal/forum/uploads/RX8TX/Manuals/CD05-xx-03le/index.html

 

Most of us have our pressure way lower than that and that will greatly lower the output of the stock injectors since they are sized to deliver fuel at that pressure.  Could be why some of us are not getting throttle response above 2/3 throttle?  What about you guys with superchargers?  Do you go lean?

 

Bill B

 


From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Bill Bradburry
Sent: Friday, June 19, 2009 10:58 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: 295cc vs 495 cc was [FlyRotary] responses to responses, not developing full power

Oh,

If you happen to be using the 6 port and plan to use only 4 of the yellow injectors, they are only good for between 173 and 197 HP at 80% duty cycle and BSFC of .5.  You would have to use all 6 to realize that higher HP that they are supposed to make.

I am thinking that they are sized small in the car because they don’t expect you to be at WOT for long in the car and they will have a chance to cool down.  In our case they will be at WOT for hours and could overheat if they were at a high duty cycle.

Thoughts??

 

Bill B 

 


From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Bill Bradburry
Sent: Friday, June 19, 2009 10:38 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: 295cc vs 495 cc was [FlyRotary] responses to responses, not developing full power

Bryan,

Well, ain’t that interesting!

That indicates that the injectors (according to calculators I found on the web) will support between 183 and 206 HP with a duty cycle of 80% and an BSFC of .5.

So much for all these wild guesses we have been making about how much power we will get with the Renesis.

 

Bill B

 


From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Bryan Winberry
Sent: Friday, June 19, 2009 10:03 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: 295cc vs 495 cc was [FlyRotary] responses to responses, not developing full power

Bill,

According to the manual, the flow rates are:

Red 69-78 ccm/15s

Blue  118-133

Yellow  89-101

 

I’m assuming the 15s means 15 seconds.  So, multiply these values by 4.

Bryan

 


From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Bill Bradburry
Sent: Friday, June 19, 2009 9:44 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: 295cc vs 495 cc was [FlyRotary] responses to responses, not developing full power

 

What is the actual size of the stock Renesis injectors?  I was under the understanding that the red primary was 295 ccm and the blue secondary was 610 ccm.  I heard that the yellow injectors from the hi power 6 port were a different size, but have never heard what size they were supposed to be.

Don, did you say you had your injectors cleaned and flowed?  What did they flow? 

Where can this information be found? Is is listed in a Mazda book somewhere?

 

Bill B

 


From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Tracy Crook
Sent: Friday, June 19, 2009 9:24 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: 295cc vs 495 cc was [FlyRotary] responses to responses, not developing full power

Mode 6 would handle it but that is for normal staging only.  The 'injector set  disabled'  is a special case In which the EC2/3 does not know which set has been disabled and therefore can't know exactly what to do.  It's up to the pilot to make the appropriate response on the mixture knob if the injectors are not the same size.

Tracy

On Fri, Jun 19, 2009 at 10:17 AM, Al Gietzen <ALVentures@cox.net> wrote:

When you switch the primary injectors off and secondary

injectors on - the EC2 is still providing the same pulse duration (assuming

engine manifold pressure, etc are the same) for the almost twice as large

secondary injectors as it did for the smaller primary injectors. Ergo, you

are feeding the engine almost twice the fuel (for the same engine

conditions) as you did when on the primary injectors.  The engine is choking

on too much fuel. 

 

Unless, of course, you have made the mode 6 adjustment to compensate for the difference in the flow rates – or will mode 6 not handle such a big differential.

 

Al G

 

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