costech

Any news on a fix for the revcounter problem on the coilpack conversion.
So I could buy one

foreigneRS

costech

what rev counter do you have, and how are driving the coilpack?

costech

I dont have a coilpack yet, i mailed stu for one but he said that he dident want to sell on before the revcounter problem was fixed.
That´s why i´m asking because i whant one for my winter car

foreigneRS

what winter car is it? what rev counter?

costech

O sorry it´s a 4x4 Sierra Cosworth
I have a Stack revcounter so for me it´s not a problem with
the counter signal, the problem is that stu don´t want to sell
the driver board before it works properly.
I understand why he wants to sort it out first, he´s
only selling top stuff

foreigneRS

oh right. yeah, with a stack you'll have no problem.

what i don't quite understand is how anyone expects a fix to come from SECS for this rev counter issue?

the coilpack driver board just splits the pulse to the amplifier in 2, but the rev counter on a sierra cosworth is driven by the green wire from the coil. if that only ever comes from 1 coil in a pair, it can only ever be half as frequent, so the rev counter will show half speed.

the modification will surely have to be done on the rev counter, nothing to do with the coilpack driver board?

Dave Henshall

he has incorporated some circuitry onto the coilpack driver board to drive the rev counter aswell, this has an extra wire that runs through the new sub loom and effectively connects to the green wire. it works aswell as long as the car is not on boost, its only then that the problems start, with the first revisoin of boards p8's were affected the worst but only some, not all, i had mine swapped to a rev 2 board for free by stu when mine stopped working (but in fact it wasnt the board at all, it was the tdc sensor it turned out) and the later baords are much better, but still read about 700 rpm low at the top end.....

im sure he will sort it, its just a matter of time... and as it doesnt affect the running of my car i'm not too bothered, would just like it to be right eventually...

foreigneRS

oh right dave. i get it now

i didn't know that the driver board also connected to the rev counter instead of the usual place on the coil

Dave Henshall

yep but as kjc has found, it may well be worth reconnecting the green wire to read half what it should from one side of the coilpack and fit a later coilpack xr3i rev counter, as this solves the problem, albeit a bit more work and expense, but its right then...

Azrael

What about connecting the wire to both sides somehow? Impossible?

Anonymous

Does seem like a simple solution that one!

Couple of diodes to make sure the signal only goes one way and jobs a good'un

But im sure there must be more to it than that or they would have done it ages ago!

Azrael

chip-3door I know nearly nothing about such electronics but if it isn't possible someone would know why....

Anonymous

Im sure Stu or SECS will be along later to point out something about that idea that we will feel embarssed for not thinking of ourselves mate

Azrael

chip-3door I'm embarrassed enough with my foolishness about my car in last 3 years, more won't make much difference



I have a very talented friend working in electronics. He custom makes lotts of different circutry. If there was interest for a fix to that and some documentation of the problem he could probably produce something easily.

foreigneRS

that has been tried. there's been a couple of topics about it.

as far as i am concerned, i will be leaving the green wire connected to one coil, and modifying my rev counter to double up the speed.

Azrael

foreigneRS so you stay in Cossie world after all? I remember that you were to sell up...

foreigneRS

Azrael sadly not, i will be selling up.

but that's something that i plan to do to the car before selling it. more out of interest than adding value though i guess.

Azrael

I see. Sad anyway :-(

foreigneRS

i will still have a 1/3rd share in a cossie, so all is not lost. Maybe I would buy the other 2/3 after getting a house

Azrael

foreigneRS good plan

Shame you don't own some blown up LHD Escos :-/

Dave Henshall

yep, the 2 wires with diodes works on some cars, but not all, apparently secs said there are times when both coils are energised at high engines speeds, which would leave no signal to the rev counter using this method

foreigneRS

you would imagine that there should be a time when both coils are energised - otherwise, what's the point of 2 coils?

Dave Henshall

costech

Another guestion does the secs coilpack driverboard have
builtin dwell control or does it just split the trigger signal in
two and use "intellegent" amplifiers to control dwell ?

the original

my secs board is a great product, but i have looked and even at high rpm it does not charge both coils at once which i believed should be one of the main reasons for designing such a system

Dave Henshall

aparently is does have active dwell.. have a read on the post on stus sig

the original

by active dwell i normally take that to mean fixed dwell time, or slightly longer dwell at high rpm/boost, which is 'active' compared to points and coil (percentage dwell)
on my secs board i'm getting around 10ms at 1000rpm, 10ms at 3000rpm but only 2ms at 6200rpm
must stress no misfires or problems though, thought at first maybe the amps had some circuitry but looks like the spark is triggered on the falling edge

Garage19

This is the circuit i have always used to drive a tacho from a ford coil pack. Has always worked fine so far.

Dave Henshall

dunno m8, would have to ask SECS....

the diagram above works for some people on some cars but not others, escos rev counters in particular dont seem to work with that setup

Ryan

as said escort cosworth clocks dont like this setup

jon@work

iTrader: (5)

if the circuit above doesn't work, try adding a 4.7K ohm 3W resistor between the zener output and earth - worked for a friend 2 weeks ago on another Ford tacho that didn't like the basic circuit - about 35 pence from RS.