From: "Stephen Izett stephen.izett@gmail.com" <flyrotary@lancaironline.net>
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Subject: Re: [FlyRotary] Re: timing on renesis engines
Date: Thu, 11 Jul 2019 08:04:51 +0800
References: <list-12749192@logan.com>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
In-Reply-To: <list-12749192@logan.com>
Message-Id: <8CB7B596-D8E7-474A-954B-7B83D5ACBECE@gmail.com>

Thank Matt
An adjustment during cranking (voltage) made sense, particularly for =
lower energy coils.
I didn=E2=80=99t realise that they adjusted dwell to RPM or MAP these =
days.=20

So at say 14v bus the dwell is adjusted from 4.16mS at 0-4400RPM then =
down to 3.36mS at 7600RPM.
So I=E2=80=99m wondering if the dwell would be safer set at 3.5mS for =
the sake of the higher RPM's

I have cool air feeding the coils.

Cheers

Steve

> On 10 Jul 2019, at 10:03 pm, Matt Boiteau mattboiteau@gmail.com =
<flyrotary@lancaironline.net> wrote:
>=20
> I attached the GM dwell settings for LS2 truck coils. Depending on the =
RPM & volts, it adjusts the dwell timing
>=20
> Yes the coils get the bus volts. On most first gen ECUs, all you got =
was one dwell setting to cover it all. Next generation added battery =
correction, so at least you could give more timing during crank vs high =
speed. Latest gen added RPM and MAP to adjust the dwell timing. Tracy's =
ECU was light years ahead of the curve back in the 2000s. We are 20 =
years later now and I would guess (don't quote me), you probably just =
get one dwell timing to cover it all.
>=20
> Are you going to notice any different, probably not.... Will your =
coils burn out any sooner? probably not compared to flying hours vs how =
many hours vehicles get. If you are concerned about coil life, change =
them every xxx hours.
>=20
> I'm running megasquirt, so they have RPM vs MAP with a general battery =
correction applied. Also with the truck coils having heatsinks, perfect =
place to add blast tubes.
>=20
> - Matt Boiteau
>> On 2019-07-10 4:31:14 AM, Stephen Izett stephen.izett@gmail.com =
<flyrotary@lancaironline.net> wrote:
>>=20
>> Hi Fin=20
>>=20
>> The coil trigger will come direct from the processor outputs I =
expect.=20
>> So your right, the coils will see whatever the bus is, whatever the =
alternator is doing.=20
>>=20
>> Steve=20
>>=20
>> > On 9 Jul 2019, at 10:52 pm, Finn Lassen finn.lassen@verizon.net =
wrote:=20
>> >=20
>> > Disregard. Those drivers are most likely for the injectors. Don't =
have the EC3 schematic so no clue what drives the coils.=20
>> >=20
>> > Finn=20
>> >=20
>> > On 7/9/2019 10:35 AM, Finn Lassen finn.lassen@verizon.net wrote:=20
>> >> All EC3 drivers are IRL530NS power MOSFETs with a on-resistance of =
0.1 ohms.=20
>> >>=20
>> >> So the voltage the coils see will pretty much be whatever your 12 =
volt bus is -- whatever the alternator outputs.=20
>> >>=20
>> >> Haven't looked at the program code but suspect that coil sees full =
voltage during the dwell time -- simple on/off.=20
>> >>=20
>> >> Finn=20
>> >>=20
>> >> On 7/8/2019 9:24 PM, Matt Boiteau mattboiteau@gmail.com wrote:=20
>> >>> Depends what voltage it's??nominal at.=20
>> >>> Look at the Miata link, it shows actual GM dwell settings from =
their ECU.=20
>> >>>=20
>> >>> You'll see RPM vs voltage for the dwell settings. I don't know =
how Tracy's computer handles the dwell.=20
>> >>>=20
>> >>> - Matt Boiteau=20
>> >>>> On 2019-07-08 7:17:34 PM, Stephen Izett stephen.izett@gmail.com =
wrote:=20
>> >>>>=20
>> >>>> So which MS document do we take as being the good oil for the =
LS2 coils. Is it 4.0mS or 3.5mS ?=20
>> >>>>=20
>> >>>> Steve Izett=20
>> >>>>=20
>> >>>> > On 9 Jul 2019, at 6:04 am, Matt Boiteau mattboiteau@gmail.com =
wrote:=20
>> >>>> >=20
>> >>>> > That's an outdated page. I'm not sure why they even keep them =
alive.=20
>> >>>> > http://www.msextra.com/doc/pdf/MS3baseV30_Hardware-1.4.pdf=20
>> >>>> > Page 93=20
>> >>>> >=20
>> >>>> > Of course that number depends what voltage is consider at =
"nominal". Not sure if Tracy's changes value based on voltage or not. =
And RPM vs Manifold pressure=20
>> >>>> >=20
>> >>>> > =
https://www.miataturbo.net/diy-turbo-discussion-14/lsx-coil-thread-82744/p=
age8/#post1380088=20
>> >>>> >=20
>> >>>> >=20
>> >>>> >=20
>> >>>> > - Matt Boiteau=20
>> >>>> >> On 2019-07-08 11:58:11 AM, Bobby J. Hughes bhughes@qnsi.net =
wrote:=20
>> >>>> >>=20
>> >>>> >> Matt,=20
>> >>>> >>=20
>> >>>> >>=20
>> >>>> >>=20
>> >>>> >> How did you end up with 3.5ms for the D585???s? At least one =
Megasquirt resource shows 4.0ms at 14VDC. My concern is the wide range =
between Tracy???s LS1 4.3ms and the 3.5ms referenced. If the megasqiurt =
information is correct then Tracy was very conservative with the LS1 =
settings. 4.0ms vs 5.6ms.=20
>> >>>> >>=20
>> >>>> >>=20
>> >>>> >>=20
>> >>>> >>=20
>> >>>> >>=20
>> >>>> >> http://www.megamanual.com/seq/coils.htm=20
>> >>>> >>=20
>> >>>> >>=20
>> >>>> >>=20
>> >>>> >> Bobby=20
>> >>>> >>=20
>> >>>> >>=20
>> >>>> >>=20
>> >>>> >> From: Rotary motors in aircraft =
[mailto:flyrotary@lancaironline.net]=20
>> >>>> >> Sent: Friday, July 05, 2019 8:03 PM=20
>> >>>> >> To: Rotary motors in aircraft=20
>> >>>> >> Subject: [FlyRotary] Re: timing on renesis engines=20
>> >>>> >>=20
>> >>>> >>=20
>> >>>> >>=20
>> >>>> >> For the LS2 - D585 truck coils, 3.5ms is the recommended =
dwell.=20
>> >>>> >>=20
>> >>>> >>=20
>> >>>> >>=20
>> >>>> >>=20
>> >>>> >> - Matt Boiteau=20
>> >>>> >>=20
>> >>>> >> On 2019-07-05 7:37:10 PM, Stephen Izett =
stephen.izett@gmail.com wrote:=20
>> >>>> >>=20
>> >>>> >> Thanks Bobby and Lyn.=20
>> >>>> >>=20
>> >>>> >> According to Tracy???s code - 2.6 mSec RX8, 3.5 mSec RX7, 4.0 =
mSec LS2, 4.3 mSec LS1.=20
>> >>>> >> I also wondered about the timing difference between the =
various coils trigger circuit actually firing.=20
>> >>>> >> Now I suppose that difference might be a few uSec and =
insignificant, but if its 100uSec=20
>> >>>> >> then the timing difference between various coil types might =
become significant.=20
>> >>>> >>=20
>> >>>> >> @ 7000 RPM=20
>> >>>> >> 1 rev takes 8.6mSec=20
>> >>>> >> So each degree of EShaft rotation is 24uSec.=20
>> >>>> >>=20
>> >>>> >> Thanks again for the help.=20
>> >>>> >>=20
>> >>>> >> Steve=20
>> >>>> >>=20
>> >>>> >>=20
>> >>>> >>=20
>> >>>> >>=20
>> >>>> >>=20
>> >>>> >>=20
>> >>>> >>=20
>> >>>> >> > On 6 Jul 2019, at 2:52 am, Bobby J. Hughes bhughes@qnsi.net =
wrote:=20
>> >>>> >> >=20
>> >>>> >> > Lynn,=20
>> >>>> >> >=20
>> >>>> >> > Default is what ever Tracy set it to. The CAS location is =
not adjustable so default is set in his code.=20
>> >>>> >> >=20
>> >>>> >> > Bobby=20
>> >>>> >> >=20
>> >>>> >> > Sent from my iPhone=20
>> >>>> >> >=20
>> >>>> >> > On Jul 5, 2019, at 12:43 PM, lehanover lehanover@aol.com =
wrote:=20
>> >>>> >> >=20
>> >>>> >> >> What is the "Default" advance? Is that checked with a =
timing light? Easy starting can be up to 15 degrees of advance. For full =
power use up to 27 degrees of advance is good up to 10,500 RPM. Boosted =
engines require less advance as boost increases. Because the effective =
compression ratio as well as charge temperature is going up. Very high =
boost my have advance closer to zero. Advance is used to allow full =
combustion=20
>> >>>> >> >> of the charge before the exhaust port opens. At higher =
pressure and temps the flame front speeds are increasing. So, less time =
is needed. Thus less advance is needed. Lowering intake air temps with =
an inter-cooler and adding water spray can allow higher boost.=20
>> >>>> >> >>=20
>> >>>> >> >> Boosting to maintain sea level performance would probably =
not shorten engine life. Boosting for additional performance does =
shorten engine life. The kids get over 600 HP with boosted drag racing =
engines. This is fine if you only need the engine for 9 seconds. You =
have to know what the actual advance is to make any decision. Mark the =
flex plate or flywheel teeth with paint so you can check actual advance =
during any RPM.=20
>> >>>> >> >>=20
>> >>>> >> >>=20
>> >>>> >> >> It is difficult to detonate an NA engine. It is not =
difficult detonate a boosted engine.=20
>> >>>> >> >>=20
>> >>>> >> >> Lynn E. Hanover=20
>> >>>> >> >>=20
>> >>>> >> >>=20
>> >>>> >> >> In a message dated 7/5/2019 10:22:44 AM Eastern Standard =
Time, flyrotary@lancaironline.net writes:=20
>> >>>> >> >>=20
>> >>>> >> >> Steve,=20
>> >>>> >> >> I???m running default timing or maybe 1 degree advanced. =
Early on I experimented with 1-2 degrees advance for many flight hours =
and did not detect any noticeable change in engine performance. I did =
push the engine to what I believe was detonation during a ground tuning =
session. I was tuning under boost (44??? MP) , 7000 rpm with a wideband =
O2 on each runner and adjusting Mode 9 and Mode 4. With F/A balanced =
between each rotor and EGT???s under 1600F I was trying to see if =
increasing timing would lower EGT???s. F/A was in the 11???s. This was =
at the end of the session and the engine and supercharger were already =
hot. I think I had added 4-5 degrees advance with no noticeable EGT =
decrease when I encountered a mild bang or misfire. This condition was =
well above my 38??? MP limit I sometimes use for takeoff.=20
>> >>>> >> >>=20
>> >>>> >> >> I???m curious about the dwell time setting difference =
between LS1 and LS2 coils. I switched to LS2 coils sometime back with no =
failures to date. I remember seeing an option setting in some of the =
code you or Finn posted. Internet research indicates LS2 coils require =
less dwell time than LS1. Possibly 0.5-1 ms less.=20
>> >>>> >> >>=20
>> >>>> >> >> Bobby=20
>> >>>> >> >>=20
>> >>>> >> >> Sent from my iPad=20
>> >>>> >> >>=20
>> >>>> >> >> > On Jul 5, 2019, at 12:58 AM, Stephen Izett =
stephen.izett@gmail.com wrote:=20
>> >>>> >> >> >=20
>> >>>> >> >> > Hi there Guys=20
>> >>>> >> >> >=20
>> >>>> >> >> > Of the guys with Renesis engines using EC2/3 can you =
comment on your timing settings.=20
>> >>>> >> >> > I???ve to date left the timing at the default setting =
figuring its set by the location of the CAS.=20
>> >>>> >> >> > Not sure if the various coil options have different =
trigger timing latency.=20
>> >>>> >> >> >=20
>> >>>> >> >> > Thanks=20
>> >>>> >> >> >=20
>> >>>> >> >> > Steve Izett=20
>> >>>> >> >> >=20
>> >>>> >> >> >=20
>> >>>> >> >> >=20
>> >>>> >> >> >=20
>> >>>> >> >> > --=20
>> >>>> >> >> > Homepage: http://www.flyrotary.com/=20
>> >>>> >> >> > Archive and UnSub: =
http://mail.lancaironline.net:81/lists/flyrotary/List.html=20
>> >>>> >> >>=20
>> >>>> >> >> --=20
>> >>>> >> >> Homepage: http://www.flyrotary.com/=20
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>> >>>> >>=20
>> >>>> >> --=20
>> >>>> >> Homepage: http://www.flyrotary.com/=20
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>> >>>> >>=20
>> >>>>=20
>> >>>>=20
>> >>>> --=20
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>> >>=20
>> >=20
>> >=20
>>=20
>>=20
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