Discussion
Got a 1600M, which at the moment has a ballast resistor. Its currently fitted with the standard 32DFM downdraught carb, and a Bosch distributor with lumenition electronic ignition.
However, we want to fit twin 40s to it, and so need a non-vac distributor. However, we've been told that the new/modern electronic ignition systems (which I think we should use because its better than points, but my dad doesn't) don't work with the ballast resistors.
Now we can't just scrap the resistor as the tacho won't work. While on the phone to bestek we were informed of a company who can replace the insides of the tacho with new bits so that you don't require the resistor but can retain the original dial etc, however my dad thinks this will be pretty expensive, an expense we could do without.
We don't seem to be able to get any accurate information from anyone really. So I'm turning to you guys,
.
Can anyone tell me what is required to get rid of the ballast resistor and keep the tacho working, thats relatively inexpensive. I'm not too bad with a soldering iron/electricals so if it can be done DIY style then thats fine.
I think thats everything, any helps guys???
However, we want to fit twin 40s to it, and so need a non-vac distributor. However, we've been told that the new/modern electronic ignition systems (which I think we should use because its better than points, but my dad doesn't) don't work with the ballast resistors.
Now we can't just scrap the resistor as the tacho won't work. While on the phone to bestek we were informed of a company who can replace the insides of the tacho with new bits so that you don't require the resistor but can retain the original dial etc, however my dad thinks this will be pretty expensive, an expense we could do without.
We don't seem to be able to get any accurate information from anyone really. So I'm turning to you guys,
.Can anyone tell me what is required to get rid of the ballast resistor and keep the tacho working, thats relatively inexpensive. I'm not too bad with a soldering iron/electricals so if it can be done DIY style then thats fine.
I think thats everything, any helps guys???
Old Coils are 9V hence ballast resistor.
New coils are 12V hence you don't need one and it can be removed. I was always under the impression that the instruments were still 12V so the Tacho connections can be made to the neg terminal of the coil (LT) and a permanent live.
If the Tacho is 9v than you can run a resistor in line on the positive feed to the tacho if required? This shouldn't affect the neg terminal on the tacho which in essence is just a pulse.
I am not the worlds greatest auto electrician though so I would double check my blurb.
N.
New coils are 12V hence you don't need one and it can be removed. I was always under the impression that the instruments were still 12V so the Tacho connections can be made to the neg terminal of the coil (LT) and a permanent live.
If the Tacho is 9v than you can run a resistor in line on the positive feed to the tacho if required? This shouldn't affect the neg terminal on the tacho which in essence is just a pulse.
I am not the worlds greatest auto electrician though so I would double check my blurb.
N.
The way forward is to convert the counter to RVC version (as opposed to RV1 reading this off the etched writing on the dial) I don't see any relationship with the modern electronics and whether it is ballasted or not, these still need 12v supply, and you either take it from the coil + if it is a 12v or the 12v supply that feeds the resistor if it is the 9v. Adrian@
Been there with this issue recently with twin 40's etc....the dial was 64.00 ish.
Been there with this issue recently with twin 40's etc....the dial was 64.00 ish.
Edited by Adrian@ on Wednesday 2nd December 20:44
Cerberus90 said:
I think thats the problem.
apparently, on the modern electronic ignition systems, the pulse isn't strong enough for a tacho to pick up, and the tacho somehow needs changing.
This is the problem, we can't seem to get a solid answer.
I have never come across that problem? the LT circuit is just that a low tension circuit. Coils don't really change that much, if anything then a Modern coil will have a higher discharge output. if you are so worried then I would just go for a Lucas type non advance dizzy and convert it to lumention to run breakerless ignition. your bosch dizzy is suitable for the bin. They are the first thing to throw away when you want to tune a x-flow. Speak to burton or Aldon and go for a basic set up. they sell Lucas dizzy's with tweaked advance curves to suit various cams and induction straight out of the box.apparently, on the modern electronic ignition systems, the pulse isn't strong enough for a tacho to pick up, and the tacho somehow needs changing.
This is the problem, we can't seem to get a solid answer.
Unless you are running a very wild spec engine with lots of compression, valve overlap and advance I wouldn't have thought your choice of ignition would make all that much difference. all breakerless ignition gives you on an average fast road engine is greater reliability and the need to lift the bonnet less frequently. Nowt wrong with your lumention set up. you may be able to re-use on the lucas but worst case would be a new stator disc for it.
If your dad is an old fart he will be well versed in setting dwell, points and plug gaps and renewing condensors during a weekend check over of the car. it is this basic knowledge that is often lacking with the yoof of today.
Keep it simple and save your money. crossys have been throwing out 140hp plus quite easily for many years before the introduction of complex and expensive electronic ignition systems.
N.
Edited by heightswitch on Wednesday 2nd December 18:22
Right, thats something to consider then.
After looking at the m-fix website, and its wiring diagram for the M, it would seem that the ballast resistor doesn't affect the tacho, as the ballast resistor only affects the +'ve going to the coil, depending on whether the engines being cranked, or if its running.
The problem seems to be, or as far as I can tell from the diagram. That when the electronic ignition system is introduced, this has the affect on the tacho, as its feed for the RPM comes from the negative terminal on the coil.
I think the reason why I want to go electronic ignition is that I'm a computer nerd, hence I believe digital to be much better, and the points system seems like a lot of faffing about. Especially when we could get a Bestek distributor+electronic ign + coil for £165, and a standard non-vac points based one from our local'ish engine place is £170ish.
Also, once I'm old enough, I will want to buy the car off my dad and it'll get used as my daily car, hence being more reliable would be pretty good, especially as TVRs are well known for their reliability, or rather lack of,.
Maybe it would make more sense to currently just stick with the points, and then move to electronic further down the road.....once its my car,
Thanks.
After looking at the m-fix website, and its wiring diagram for the M, it would seem that the ballast resistor doesn't affect the tacho, as the ballast resistor only affects the +'ve going to the coil, depending on whether the engines being cranked, or if its running.
The problem seems to be, or as far as I can tell from the diagram. That when the electronic ignition system is introduced, this has the affect on the tacho, as its feed for the RPM comes from the negative terminal on the coil.
I think the reason why I want to go electronic ignition is that I'm a computer nerd, hence I believe digital to be much better, and the points system seems like a lot of faffing about. Especially when we could get a Bestek distributor+electronic ign + coil for £165, and a standard non-vac points based one from our local'ish engine place is £170ish.
Also, once I'm old enough, I will want to buy the car off my dad and it'll get used as my daily car, hence being more reliable would be pretty good, especially as TVRs are well known for their reliability, or rather lack of,
.Maybe it would make more sense to currently just stick with the points, and then move to electronic further down the road.....once its my car,
Thanks.
Adrian@ said:
The way forward is to convert the counter to RVC version (as opposed to RV1 reading this off the etched writing on the dial) I don't see any relationship with the modern electronics and whether it is ballasted or not, these still need 12v supply, and you either take it from the coil + if it is a 12v or the 12v supply that feeds the resistor if it is the 9v. Adrian@
Been there with this issue recently with twin 40's etc....the dial was 64.00 ish.
ah, didn't see this, posted at exactly the same time as I had, Been there with this issue recently with twin 40's etc....the dial was 64.00 ish.
Edited by Adrian@ on Wednesday 2nd December 20:44
.thats not too bad IMO, £64.
I think my dads going to ask you about it tomorrow when he comes to pick up the suspension.
The idea we've had so far is basically what heightswitch said.
Get a Lucas non-vac distributor with a tweaked curve, then fit our existing lumenition electronic ignition kit (which works fine now, tacho works etc). And then we don't get rid of the ballast resistor.
Edited by Cerberus90 on Wednesday 2nd December 21:44
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