CHT balance - ljet

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type11969
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Re: CHT balance - ljet

Post by type11969 » Sun Aug 27, 2017 9:12 pm

Good to know, I'm definitely interested to dig in to the details - will I be able to tweak inj duty cycle per cyl? Assuming yes, but if not, I'll fall back on megasquirt. Once I have the hardware set up, the move from one to the other should be "easy".

I have a few year old "ign-4" waste spark module and a pair of bip363 drivers . . . Kinda wish I had sprung for "smart" coils, but I'll start with these. Not really sure where to start on the ignition map side, I think I have a better idea about fuel. Definitely more research to do.

In more analog news, I finally took the time today to figure out how the AFM/adjustments work. Assuming this post is accurate

https://www.thesamba.com/vw/forum/viewt ... 7d913ff921

my flapper was much too tight/running lean. Certainly CHTs agree along with my almost fully threaded in idle mix screw. Anyway, I loosened up the cog by 9 or so teeth to get to the 60gram target. Pretty much dropped the afr 1-1.5 points across the map - idle mix screw is now back at mid point. More importantly, #3 is now running at least 10-15 deg cooler - around 380 now when I used to almost be pushing 400. Good news. I do think that it's a bit too rich under light, lower speed, conditions, but I don't know that I have enough adjustability to correct.

Anyway, at least good enough to keep me going until the speeduino is operational.

-Chris

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Piledriver
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Re: CHT balance - ljet

Post by Piledriver » Mon Aug 28, 2017 1:01 am

The 4 tower 106(x) can be had for ~$40 new... and next to nothing used, with a pigtail...almost not worth modding the box.
I ran my first setup with the drivers all in an external box, had to run 5v to them for pullups when I switched to ls2 coils.
Worked fine.
I, for one, regularly embrace our new robot overlords, as I am the guy fixing the robots...

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type11969
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Re: CHT balance - ljet

Post by type11969 » Mon Aug 28, 2017 6:33 pm

Pile-

Thanks, does the 106(x) have internal drivers? Can you share a PN or link for it and/or the ls2 truck coil? Cutting out an external driver sounds like a good move.

-Chris

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Re: CHT balance - ljet

Post by Piledriver » Mon Aug 28, 2017 10:10 pm

Both types are logic driven.

Good price on VW 106(e) coil latest version IIRC genuine Beru.(OE)
http://www.autohausaz.com/search/produc ... oFEALw_wcB

Here's an OE LS2 truck coil new, not the greatest price, but part# and image are useful, also google for mounts as they are somewhat difficult to mount neatly, std LS2 coils are easier to mount.

https://www.summitracing.com/parts/ado- ... KHEALw_wcB
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type11969
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Re: CHT balance - ljet

Post by type11969 » Tue Aug 29, 2017 6:49 pm

Perfect, thanks

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Clatter
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Re: CHT balance - ljet

Post by Clatter » Wed Aug 30, 2017 5:36 pm

FWIW, you are going to want to re-visit the two major adjustments on the AFM. (And the minor one at idle when you are all done.)

Once you get your cog wheel spring to where your cruise AFM is right,
Then you can adjust the 'wiper', to tweak the baseline so low-speeds and idle are nice and lean (where you don't have to worry about getting hot).

Then re-visit your cog wheel...

Did you ever switch the injectors around to see if the problem follows the injector?
IIRC, there are some who say #1 is hottest, and some who say #3..
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type11969
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Re: CHT balance - ljet

Post by type11969 » Wed Aug 30, 2017 7:24 pm

Thanks for the feedback. I did swap the injectors, but I also adjusted the AFM at the same time (limited time to fiddle on Sunday). All of the temps went down, so inconclusive if the injector was a factor, but considering the current #3 temp, even if the injector was a factor, it wasn't much of one.

Regarding revisiting the adjustments, the only way (I think) I can keep running this cool on #3 is to not lean out at all at cruise. If I move the wiper, I move the entire curve in the lean direction - including at cruise. But, if the flap position to fuel delivery curve is very flat around where I am currently "cruising", I can see how moving the wiper wouldn't impact cruise mix significantly. Any feel for curve "flatness"? I thought I read that the wiper had a significant impact at higher rpm, but that could be hearsay.

Or I can lean out via the cog and richen up via the wiper in hopes of ending up in the same spot at cruise. Or vice versa. But the only "constant" I have right now is the 60gram door "cracked" number, I think if I relax all of the constraints, I'll just chase myself in circles.

Any tips/tricks appreciated.

-Chris

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