Am I crazy or could this work?

They go by many names, P01, P59, VPW, '0411 etc. Also covering E38 and newer here.
Chuff
Posts: 267
Joined: Thu Dec 20, 2012 5:28 pm
Location: Melbourne

Re: Am I crazy or could this work?

Post by Chuff »

I'm not sure whether or not it's possible to change the firing order, such as in your example from 18726543 to 13421342, and that's not the way I envisaged it. Using your firing orders I would wire up the coil & injectors as follows:

1 => 1
8 => nothing
7 => 3
2 => nothing
6 => 4
5 => nothing
4 => 2
3 => nothing

and then disable DTCs & fault flags for 8, 2, 5 & 3.

By your logic, if it works as I'd imagine it, each cylinder will receive a spark during the exhaust stroke which won't make a stick of difference such as in all wasted spark systems but it would also get a shot of fuel during the exhaust stroke & I'd imagine that would produce somewhat unwanted results. :wtf:

From the small bit of research I have done looking into this it should be possible to wire up the coils & injectors as I have stipulated above, as well as disable the DTCs & fault flags for the missing cylinders and simply work assuming you provide it with the correct crank & cam position signals.

Then comes the sticky bit as mentioned by antus earlier:
antus wrote:It would take a quite a bit of tuning, as it'd be set up for the amount of air and advance a v8 is expecting, and thats probably the biggest reason people dont do it. There are a lot of tables in those PCMs, and its a lot easier to start off with a pretty close platform and not need to change most the calibration. Moving to a 4cyl would be more work after you got the hardware working.
But, if you could get correct data into those tables then any custom/programmable V8 binary will work once the DTCs, flags and tables have been set accordingly.

Well, that's the way I see it, but I'm no expert.

Chuff
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NSFW
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Re: Am I crazy or could this work?

Post by NSFW »

I think the extra fuel pulse would happen during the combustion stroke, which ought to work just fine. I'd expect it to work better than throttle-body injection, for example... And way better than carburetors! :)

You'd just have to tell the PCM that the injectors flow twice as much as they actually do, so that it will cut the pulse times in half.

I think it's worth a try. If problems come up, I bet we can find ways around them.
Please don't PM me with technical questions - start a thread instead, and send me a link to it. That way I can answer in public, and help other people who have the same question. Thanks!
Yortt
Posts: 131
Joined: Mon Apr 13, 2009 10:11 am

Re: Am I crazy or could this work?

Post by Yortt »

PO1 4cyl testing
RIMG0667.JPG
RIMG0661.JPG
Attachments
RIMG0677.JPG
RIMG0676.JPG
RIMG0669.JPG
Thorwon
Posts: 95
Joined: Wed Jan 16, 2019 1:34 am
cars: 2007 Hemi powered JKUR
1987 YJ
1955 CJ5
1988 MJ Comanche
Location: Commerce GA.

Re: Am I crazy or could this work?

Post by Thorwon »

This is what I'm working on.
viewtopic.php?f=42&t=7810&p=116204#p116204
Bad things happen FAST!!!
Thorwon
Posts: 95
Joined: Wed Jan 16, 2019 1:34 am
cars: 2007 Hemi powered JKUR
1987 YJ
1955 CJ5
1988 MJ Comanche
Location: Commerce GA.

Re: Am I crazy or could this work?

Post by Thorwon »

Yortt wrote:PO1 4cyl testing
RIMG0667.JPG
RIMG0661.JPG
That looks like it'll be fun.
Tell me about your setup/programming.
Bad things happen FAST!!!
Yortt
Posts: 131
Joined: Mon Apr 13, 2009 10:11 am

Re: Am I crazy or could this work?

Post by Yortt »

Thorwon wrote:
Yortt wrote:PO1 4cyl testing
RIMG0667.JPG
RIMG0661.JPG
That looks like it'll be fun.
Tell me about your setup/programming.
My setup/programing was initiated after Dick at Dick's Electronics was progressing his conversion project on a 4 cylinder turbo Toyota we both have the cars running and drivable now but still require work sorting out fine tuning. Dick is using his RTLS1 hardware/software and operating system which is different to me. I am using HP Tuners with the 1290005 operating system on my turbo 4 cylinder engine. The start tune was sourced from my son's LS1 turbo running a developed E85 tune the PCM thinks it is running a V8 engine with appropriately connected coils and injectors to the 4 cylinder engine. So does it work YES, can the fine tuning be sorted out, time will tell.
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