Ford Cortina / Rover V8 3.9 / bank fire / wasted spark

Testing and development of Megasquirt 3

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wes kiser
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Re: Ford Cortina / Rover V8 3.9 / sequential / wasted spark

Post by wes kiser »

jsmcortina wrote:Tested out the dev code (in between 0.18 and 0.19) just now.

I did some experimentation with fuel trim while looking at EGT. I only have three installed at present (despite a full set waiting on the bench.)

It seemed the inner cylinders on the V8 were running a lot hotter (say 70degC) than the outers. I added 12% to the inners, all over. I took 10% out of the outers in the idle region. I didn't want to pull any more out until I've really tested it and get all the EGTs in there. This resulted in all three sensors reporting around 580degC.

With those changes my idle immediately smoothed out, "sounded happier" and the AFR read rich (12.5.) I was able to take about 6% out of my idle VEs and still keep it smoother with low 13 AFRs.

There's plenty more tuning to be done, but this certainly looks a promising start. The trim results seem consistent with that aero engine paper that was linked here. The leaner running on inner cylinders is consistent with the fact that over the years when I've melted a piston on nitrous it has always been no.6.

James
It is relatively common for the inner cylinders of most v-8's (those with manifolds rooted in older carbureted designs) to tune out at a higher rpm than the outers (the runners are naturally longer).
86 Rx-7, swapped to 2.3 ford turbo (BW EFR 6758), ms3/ms3x sequential fuel /waste spark, ls2 coils
88 Tbird 2.3t, Microsquirt Module (PIMP), TFI ignition
jsmcortina
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Re: Ford Cortina / Rover V8 3.9 / bank fire / wasted spark

Post by jsmcortina »

Another positive update.

Yesterday I ran the Cortina on an UNHACKED Megasquirt for the first time ever, while using lots of features that formerly needed hardware mods and spaghetti inside the box.

V357 board
MS3
MS3X

4 MS3X logic spark outputs feeding external 4 way BIP ignition box driving 2x EDIS-style coilpacks.
8 sequential injectors from the MS3X
VR crank sensor
hall cam sensor
launch input switch
nitrous enable input
2 stages of nitrous output
shift light
tacho output
Idle-up switch input
Nitrous bottle temperature on MS3X ADC input
(Soon to come nitrous and fuel pressure ADC inputs)

I also have a CAN-connected "Extender" board for 8 EGT, wheel speed,
exhaust back pressure, accelerometer and real-time clock.

James
I can repair or upgrade Megasquirts in UK. http://www.jamesmurrayengineering.co.uk

My Success story: http://www.msextra.com/forums/viewtopic ... 04&t=34277
MSEXTRA documentation at: http://www.msextra.com/doc/index.html
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prof315
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Re: Ford Cortina / Rover V8 3.9 / bank fire / wasted spark

Post by prof315 »

Sweet, I especially like the idea if the external BIP box. Can you post pics of it... I am still undecided in how I want to do my ignition with the 20/20 turbo beast that is in the works and 4 BIPs with either Ford or BMW COPs is one possibilty. LS2 CNPs is the other option but I am a little worried about finding plug wires that will work for me.
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jsmcortina
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Re: Ford Cortina / Rover V8 3.9 / bank fire / wasted spark

Post by jsmcortina »

prof315 wrote:Sweet, I especially like the idea if the external BIP box. Can you post pics of it...
http://www.msextra.com/forums/viewtopic ... 67&t=36066

James
I can repair or upgrade Megasquirts in UK. http://www.jamesmurrayengineering.co.uk

My Success story: http://www.msextra.com/forums/viewtopic ... 04&t=34277
MSEXTRA documentation at: http://www.msextra.com/doc/index.html
New users, please read the "Forum Help Page".
jsmcortina
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Re: Ford Cortina / Rover V8 3.9 / bank fire / wasted spark

Post by jsmcortina »

I took advantage of the unusually cold UK temperatures today. The Cortina fired up beautifully at an indicated -5C. It took a few turns and then burst into life and idled just fine. No coaxing of the throttle, no stallouts. Ran great.

James
I can repair or upgrade Megasquirts in UK. http://www.jamesmurrayengineering.co.uk

My Success story: http://www.msextra.com/forums/viewtopic ... 04&t=34277
MSEXTRA documentation at: http://www.msextra.com/doc/index.html
New users, please read the "Forum Help Page".
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