X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from willowsprings.uwyo.edu ([129.72.10.31] verified) by logan.com (CommuniGate Pro SMTP 5.4c2) with ESMTPS id 4901358 for flyrotary@lancaironline.net; Wed, 09 Mar 2011 20:37:06 -0500 Received-SPF: none receiver=logan.com; client-ip=129.72.10.31; envelope-from=SBoese@uwyo.edu Received: from ponyexpress-ht1.uwyo.edu (ponyexpress-ht1.uwyo.edu [10.84.60.208]) by willowsprings.uwyo.edu (8.14.4/8.14.4) with ESMTP id p2A1aT0c004185 (version=TLSv1/SSLv3 cipher=AES128-SHA bits=128 verify=FAIL) for ; Wed, 9 Mar 2011 18:36:30 -0700 (MST) (envelope-from SBoese@uwyo.edu) Received: from ponyexpress-mb5.uwyo.edu ([fe80::9813:248c:2d68:a28b]) by ponyexpress-ht1 ([10.84.60.208]) with mapi; Wed, 9 Mar 2011 18:36:29 -0700 From: "Steven W. Boese" To: Rotary motors in aircraft Date: Wed, 9 Mar 2011 18:36:15 -0700 Subject: RE: [FlyRotary] Injectors dead time was : [FlyRotary] Re: more staging and tuning Thread-Topic: [FlyRotary] Injectors dead time was : [FlyRotary] Re: more staging and tuning Thread-Index: AcvevugOmiORo8uoTWy/KpffLuMg5AAAM5fg Message-ID: References: In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US Content-Type: multipart/alternative; boundary="_000_E1AA3B1AF41D8049B1E3FBD5E22562600887397165ponyexpressmb_" MIME-Version: 1.0 --_000_E1AA3B1AF41D8049B1E3FBD5E22562600887397165ponyexpressmb_ Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Ed, Thanks for the information you found. I considered constructing the circuit that I use to extend the pulse width = in such a way as to reduce the current during that extended pulse time. Th= at would approach peak and hold operation to some extent. I decided not to= do this in the interest of making incremental changes instead of several a= t once. An added resistor for each channel would do this, but the short ti= me that the current would be reduced at the end of the pulse isn't really w= hat one would want. Each channel is individually adjustable in terms of th= e added pulse width, though. In the interest of putting my money where my mouth is (or where socks may s= oon be) I have used the information Bill provided and have a set of blue an= d red RX8 injectors on the way. Assuming that they check out and that I ca= n install them without too much trouble on my engine stand, we'll find out = if the tuning works as I hope. The proof is not in the saying but in the d= oing. Looking forward to giving a tuning demonstration at the next Rotary Roundup= or some unique cuisine. Steve From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Beh= alf Of Ed Anderson Sent: Wednesday, March 09, 2011 6:02 PM To: Rotary motors in aircraft Subject: [FlyRotary] Injectors dead time was : [FlyRotary] Re: more staging= and tuning Thanks, for the additional annotation on the chart, Steve. That does make = it clear what is happening during the "perturbation" phase. Here is a sample of some "dead time" of various fuel injectors I found on t= he web - the first number is dead time in microseconds. So as can be seen = the dead time due to injector latency can vary (in this case from a low of = 540 usec (approx 1/2 msec) to a high of 1600 usec or 1.6 msec. Stock Blue injectors: 728/420CC STI Pink injectors: 728/ 550CC PE 650's : 1500/650CC PE 800's : 1600/850CC Helix 660: 1180/660cc UR 785s: 770/785CC UR 785 D type 540/785CC Helix 820CC: 1120/820CC SIDE FEED injectors: Stock US STI: 1050/500CC Nismo 720cc : 880/720CC PE850s : 850/850CC Here is a link to even more injectors and their dead times http://injector-rehab.com/shop/lag.html Interestingly in this link also shows the apparent effect of voltage on dea= d time and the advantage of peak and hold injectors in reducing (but not el= iminating dead time) Ed --_000_E1AA3B1AF41D8049B1E3FBD5E22562600887397165ponyexpressmb_ Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Ed,

 

Thanks for the information you found.

<= p class=3DMsoNormal> 

I considered constructing the circ= uit that I use to extend the pulse width in such a way as to reduce the cur= rent during that extended pulse time.  That would approach peak and ho= ld operation to some extent.  I decided not to do this in the interest= of making incremental changes instead of several at once.  An added r= esistor for each channel would do this, but the short time that the current= would be reduced at the end of the pulse isn’t really what one would= want.  Each channel is individually adjustable in terms of the added = pulse width, though.

 <= /p>

In the interest of putting my money where my mouth is (or where s= ocks may soon be) I have used the information Bill provided and have a set = of blue and red RX8 injectors on the way.  Assuming that they check ou= t and that I can install them without too much trouble on my engine stand, = we’ll find out if the tuning works as I hope.  The proof is not = in the saying but in the doing.

<= span style=3D'font-family:"Arial","sans-serif";color:black'> 

Looking forward to giving a tuning demonstration at the= next Rotary Roundup or some unique cuisine.

<= o:p> 

Steve

&n= bsp;

 

From: Rotary motors in aircraft [mailto:= flyrotary@lancaironline.net] On Behalf Of Ed Anderson
Sent: Wednesday, March 09, 2011 6:02 PM
To: Rotary motors in aircraft=
Subject: [FlyRotary] Injectors dead time was : [FlyRotary] Re: m= ore staging and tuning

 

Thanks, for the additional annotation on the chart, = Steve.  That does make it clear what is happening during the "per= turbation" phase.  

 

Here is a sample of some "dea= d time" of various fuel injectors I found on the web - the first numbe= r is dead time in microseconds.  So as can be seen the dead time due t= o injector latency can vary (in this case from a low of 540 usec (approx 1/= 2 msec) to a high of 1600 usec or 1.6 msec.   <= /p>

 

 

Stock Blu= e injectors: 728/420CC
STI Pink injectors: 728/ 550CC
PE 650's : 1500= /650CC
PE 800's : 1600/850CC
Helix 660: 1180/660cc
UR 785s: 770/78= 5CC
UR 785 D type 540/785CC
Helix 820CC: 1120/820CC


SIDE F= EED injectors:

Stock US STI: 1050/500CC
Nismo 720cc : 880/720CCPE850s : 850/850CC

Here is a link to even more injectors and their dead times

 

&= nbsp;

Interestingly in this link also shows the apparen= t effect of voltage on dead time and the advantage of peak and hold injecto= rs in reducing (but not eliminating dead time)

<= div>

 

 

 

Ed

 

=  

= --_000_E1AA3B1AF41D8049B1E3FBD5E22562600887397165ponyexpressmb_--