I'm looking at replacing my powerspark with a 123 ignition. I'm trying to decide between the basic 123 with the preset dial and the tune+ with Bluetooth etc. The basic one looks easier to set up, but does anyone have experience of setting up the tune +, setting the curve etc.. It's obviously more adjustable but is it overcomplicated for my application? How difficult is it to find the right curve compared to the presets of the basic model? It's going on an 1800 type 4 with twin dellorto carbs. Looking to add a layer of reliability after a few intermittent faults.. Any setup experience, please share!
Usually, the first question anyone with a 123 tune asks is ‘does someone have a standard curve’. The pre-set curve will work just fine for your 1800.
@77 Westy speaks the truth. I'd bet most folk who bought the programmable one end up using the default curve. Unless you've got the engine on a dyno, you'd be guessing what values to program into it. 123 pricey but well worth having, IMHO. Won't necessarily fix your "intermittent faults" - what are they?
It started cutting out intermittently on our last trip. (Not under engine load at the time) Died, started again after a few minutes, ran for 10 mins, died again repeat. After a few times of this, recovery trip home. Checked and changed fuel filter, looked pretty clean. Checked connections, earth etc at coil and distributor. Carbs checked for dirt too.. Just trying to eliminate things as I lost a bit of confidence in her! It happened at convenient times this time but maybe not next time! 123 seems to add a layer of reliability..
All of the 123 distributor curves are more curvey than a stock one which is defined by 2 straight lines, but the acceptable margins around the ideal advance curve are quite large...so...does it matter whether it's a curve or 2 lines or that you can fine tune it? Probably not. It's handy to have starting, idle advance and where the curve starts and ends independent if you feel the need to change one aspect but not another. For most people a stock curve is fine.
Ok, ta. Sounds like the standard 123 is fine for me.. Thanks for the replies, I've had a read at some previous threads and the tune+ seems to open up a wormhole I don't really need to go down!
Hopefully you meant the 123/VW-R-V with vacuum (load) sensing. https://www.123ignitionshop.com/gb/volkswagen/243-123vwrv.html This has all the features you, or rather the engine, really need. The basic 123/VW-R is equivalent to a 009, and you don’t want that. Concerning the intermittent faults with the Powerspark, have you replaced the distributor cap and rotor arm with decent quality ones?
Yeah, the vacuum one is the one I meant.. Haven't tried changing the cap and rotor arm yet. Problem is trying to replicate the fault!
Most reliable ignition would probably be a well-maintained Bosch distributor with regularly checked and adjusted points. The Powerspark may have simply been overheating more and more easily as it got older, a common trick. Those in the know carry a complete pre-timed distributor with a clamp. The 123 will fix that one. But so will a new £40 module. Or a set of points and a condenser.
I have always been curious about these ignition systems not because I am expecting to do a lot of fine tuning but because finding a good distributor with a working vac can for a type 4 can be difficult. For years I have been running a Bosch 050 mechanical advance distributor and wondered if I was missing out on not running a vac advance unit. I understand the theory of what they do, but don’t know how much it affects driving performance in a bus. When I think about vacuum advance, I picture the fuel economy gauge on my Subaru. When I am pressing on the throttle it moves a lot and falls off again when throttle position stops changing. That is the vacuum that kicks in that little bit of advance before rpm has a chance to advance it even more when moving off or accelerating. I least that is my understanding.
You won't get much of the the mileage advantage as a bus is so heavy you barely ever cruise on idles with the vacuum advance operating (too much foot in it). You would find it pulls off from a stop more smoothly with less revs and clutch slipping needed to keep the engine going.
One possibility is your coil. If they go open-circuit when they're hot, it can be a nightmare to diagnose. If you are getting a 123, worth changing your coil as well. A bog-standard Brazilian Bosch will do the job.
This is precisely what happened to me on holiday. The fuel saved in the little courtesy car paid for the new coil.
I’ve you’ve got the cash burning a hole in your pocket, I’d get a 123. The advance is done electronically, and the spark-balancing works really well (on a type 1 at least).
That’s kind of what I thought. Most of the limited tuning I have done is getting it to idle steadily and move off nicely from idle. After that, there doesn’t seem to have been a lot of difference in the distributors I’ve tried. I do have a working vac can now so I will be using it with the stock dual carbs. It’s nice to know there is an alternative, though. It’s a bit like camshaft selection. Performance tuning on a bus seems to not accomplish anything exciting, though getting it to run cool and reliably is exciting enough.
Mines been on a 1641 type 1 with a standard Solex for about 7 or so years now. It wasn't cheap but well worthwhile in my view. The cost sort of got lost when the restoration bill went into orbit after they couldn't find any metal that wasn't like tinfoil with holes punched through it.
Might treat our van to one of these. Is there an issue with the length of these distributors and the clamp positioning? Thought i read it somewhere. Also is there a selectable advance curve for a type 4 on the standard vac advance one? Also what’s reliability like compared to a Pertronix? Has anyone had one fail?
When all's said and done there isn't much if any difference between a type-1 and type-4 curve which is why in general the same distributors are sold as suitable for both. If anything a type-4 doesn't like quite so much full advance. There's bound to be a curve that fits the bill and even if it was "Type-4" would that be intended for a 2L bus or a 1700 car? The best thing is do your homework, it's all on the net. Find which distributor came with your engine type and vehicle, find the curve, find the 123 curves and compare. 2L buses came with a 021 905 205P or S distributor but they are the same thing other than the rev limiting rotor IIRC. 1800 probably the same or near enough. @mikedjames posted all the curves on Samba, 123 do somewhere show their curves. Hard work to be sure!
