Memcals: Knock sensors and limp home resistor packs

[hakhawk]

ok, just been doing some reading on thirdgen.org, and it seems the 2 ic's, one is for limp home, and the other is the netres, which actually determines how mnay cylinders the memcal is used for, i assume this is where things are ging haywire.

http://www.thirdgen.org/techboard/diy-prom/345727-cylinder-select-netres-values.html

this thread has the info, and from what i can gather, this image: http://i4.photobucket.com/albums/y103/gijim/netres.jpg

will help us modify a v6 memcal to work fine with a v8 binary, but obviously with weird limphome still. and can obviously be done the otherway, but i doubt thatll happen anytime soon. time to find which memcal in my pile is that camira one.

 

[TO4355]

holy crap theres some good info there......well done

im going to have a good read now

 

[Chuff]

OK. What I'm reading here then is that the knock board on the V8 & V6 memcals are identical, so if I were to take the knock board off a V6 memcal and solder it into a V8 memcal, and use a knock sensor from a V6 it should all work, correct?

 

[TO4355]

yes mate thats correct

you will have to enable the KS in the binary though

 

[hakhawk]

hey TO4355, could you grab a v8 memcal and measure the resistances on that picture i linked to, i just checked the v6 one and its same as the v6 one in the pic.

 

[TO4355]

same as pic mate
pin 3 to pin 13 is exactly 7.49K

pin 13 to pin 12 is open

pin 12 to pin 11 is 10K

 

[hakhawk]

cool, so you can test that next dyno run, make the v6 netres resistors like the v8 one.

one thing though:

So, turning a v6 into a v8 memcal seems simple, just cut the CAL56 and put a 7.5k resistor to CAL53, or on the 16 pin chip itself, put a 7.5k resistor from pin 3 to pin 13. *edit: err, pin 13 no longer has any connection to anything because you physically removed it. I meant a 7.5k resistor from pin 3 to the pin socket on the memcal where pin 13 used to be.

why put a 7.5k resistor in, when the netres already has a 7/5k resistor in exactly same spot?


edit: worked it out, i thought theyd lift pin 12 and be done with it, but theyve lifted pin 13, due to the fact that maybe pin 12 has other uses. tis all good.

 

[TO4355]

im thinking that pin 12 has to be cut..........so it doesnt interfere with the other resistance figure

so what has to be done with the pin 12 on the memcal maybe just put a 10K resistor between pin 12 and pin 11 to mock it back to how it was

 

[hakhawk]

dunno, id probably just do it how they have for a start, seems to have worked for them.

 

[TO4355]

how do they work out
CAL56
CAL53
CAL62 ?????