CIS conversion ?s

Fuel Supply & Ignition Systems

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you
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Re: CIS conversion ?s

Post by you » Thu Jul 18, 2013 10:51 am

just a shot of sensor location if thats what youre looking for, wombat

Image

heres a little cone comparison for those interested...numbers are estimates and the math is fuzzy but its close enough to give an idea of how they differ...the values on the right are the differences between plate area and cone area at the profile change..not at all accurate as the plate would be at an angle but provides a roughstimate idea of air flow past the plate

Image

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Jadewombat
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Re: CIS conversion ?s

Post by Jadewombat » Tue Jul 23, 2013 8:53 pm

Just curious about your intake, TB, and airbox. I played with a couple of them, the rabbit fuel meter and Golf TB seemed to work best for my 1600.

you
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Re: CIS conversion ?s

Post by you » Tue Jul 23, 2013 11:32 pm

wombat, pics of it all are posted in one of the previous pages...

ive noticed that i have a bit of a flat spot at times between 1500-2500rpms...might be spark related but im thinking fueling..maybe a 60mm plate will help with velocity thru the meter and reduce the lag...i dunno, just thinkin out loud....

i put in the 80mm volvo cone out of curiosity to see how it performs...havent fired it up yet with that in it but it has the steepest full throttle enrichment section if the engine even pulls enough air to get into that portion of the profile..the part throttle section is not so far off from the jetta one i was running...itll be interesting to see....

another thing ive noticed is that with the jetta cone it runs pig rich if im at a lite cruise and have the throttle only slightly open, ie foot on pedal but not really depressed...seems to like either being on throttle or off...im wondering if using a basic cis air meter wont help with that..the volvo "idle" cicuit is not so steep as the jetta

ill update once theres something to report

on another note, just looking at the smc switches and data sheets it appears my electronics theory isnt quite up to snuff...anyone familiar with npn current sourcing/sinking versus an analog output?...right now im under the assumption i would need an analog output to drive the dpr

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Piledriver
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Re: CIS conversion ?s

Post by Piledriver » Wed Jul 24, 2013 12:27 pm

it's a digital out as far as the switch is concerned, but analog out as far as the DPR sees.

SMC switch and a potentiometer for one setting that kicks in/out. (may need a relay or buffer transistor to supply current)
Switch turns on>adds more current>more fuel. Adjust the pot to set the current.

A MS or such could do the same with PWM output, with a wide range if you were really motivated.
I, for one, regularly embrace our new robot overlords, as I am the guy fixing the robots...

you
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Re: CIS conversion ?s

Post by you » Fri Jul 26, 2013 9:04 am

smc and sunx offer soo many options...i was inclined to get one that would drive the dpr directly just to make the wiring simpler and allow me to make the necessary adjustments at the switch rather than a pot...guess it will all come down to what unit im able to find and afford

fired up the van with the big volvo airmeter and drove it around the block...the tuning was crude but the full throttle enrichment appears to work fairly well...i dont have the idle and off idle adjusted right yet but at cruise the afr sat at 13.5 and when i got on the gas it kicked down to 12.5...need to dial in the lower rpm range and take it for a longer drive....

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