TheSamba.com :: View topic - Bluetooth (123 ignition) distributor installation questions

Fri Aug 25, 2023 10:12 pm

So folks, I've just gotten new 123 ignition (brand name) distributor, and I wanted to replace old one.

This new distributor has vacuum advance port. However, old one (currently installed) has no vacuum advance port. It's not connected to my weber 32/36 dfav carburator. I have single carb setup, here is pic for your reference (disregard the carb on this picture, I switched to a new one few months ago):

Today I opened the engine bay and tried my best to understand how to install the distributor. Should I mention I gonna do it for the first time?

What I cannot understand is four things:

1) Do I need to setup vacuum advance hose if I haven't gotten one in my current setup? I think the answer is yes, but wanted to hear your confirmation.

2) When I look into vacuum advance port on my weber 32 36 DFAV, I can see a strange picture. It seems there is some sort of black cap at the port. I'm wondering what this is?

Here are the pictures of this port (as I think) and cap:

3) I haven't gotten vacuum hose, can I just buy it in O'Reilly Auto Parts or it's some sort of special vacuum hose? How do I secure the hose so it won't go off?

4) Do I need strobo light? I realized that I probably need one.

I wanna do all the setup myself, so I understand that sh*t better in case of breakdowns down the road. Thanks for your help, I appreciate it.

Sat Aug 26, 2023 7:06 am

Get yourself a timing light, you'll need it to verify that the advance curve you program into the 123 tune is correct (you don't want to end up over advanced). Also worth getting a cheap vacuum gauge as well so you can easily check the ports.

Vacuum hose is nothing special, just any good rubber hose that fits properly so it doesn't have any leaks. You need that connected to get to play with the MAP setup on the 123 tune but as far as I can tell (and someone with more knowledge about these will chime in and correct me if I'm wrong) you can run it without vacuum so just centrifugal advance.

I've just got hold of a 123 Tune which I'll be fitting next week to replace an old switched 123, interested to see what curves you end up with.

Sat Aug 26, 2023 7:14 am

There's a "screw" in the vacuum port to plug it. Just unscrew it and save it if needed in the future.

Sat Aug 26, 2023 10:30 am

If you previously just had an 009 distributor with only mechanical advance, then just going to a distributor with a vacuum advance should give you a noticeable improvement in part throttle performance and gas mileage.

Sat Aug 26, 2023 10:38 am

If you'll be 'living the life' of a bus operator, timing light/gun is #1 or 2 on the list along with feeler gauges as far as 'I'm driving this & will do so for an unspecified time into the future'.
Timing is important, if it's wrong, the repairs get expensive.
And as far as clamps, the vacuum line seems to never need any.

Sat Aug 26, 2023 11:56 am

Wildthings wrote: If you previously just had an 009 distributor with only mechanical advance, then just going to a distributor with a vacuum advance should give you a noticeable improvement in part throttle performance and gas mileage.
As long as that Weber makes vacuum the distributor can use, some suck slightly at idle and the VW style distibutor is too sensitive so it's advanced all the time.

Mon Aug 28, 2023 9:51 am

yes, you want to hook up the vacuum.
yes, that is the right port on the carburetor.

you just need to unplug it and put a hose on it.
i've always just used german cloth braided line for that and i believe it's 5mm ID. you can pretty much use whatever you want.

you shouldn't need a hose clamp (it's under vacuum)
if it blows off, you have worse problems :)

the 123 is an excellent choice and you will love it once it's setup. it's much better than an old skool distributor. and can be particularly useful when you have a non-stock application where the fuel induction has been changed, e.g. if you don't have the same vacuum signal as stock and an off the shelf SVDA may not be as responsive

yes, you will need a timing light. this will allow you to set up your base timing. this is critical.
everything in your 123 tune app will be relative to that value, since it's basically adding timing advance relative to that base timing. the base timing is an absolute. everything the software does is relative to that.

you are using the light to set the static timing - which is a product of the physical position of the distributor relative to the engine - when you install the distributor... all the numbers in the tables in the 123 app for advance are set up based on vacuum and "centrifugal" (it's really just RPM tacho signal based, not actually centrifugal but they call it that because in a regular distributor, it is...because it's using springs and weights spinning around). those numbers are added to the base (static) timing.

so, if you use the light and set the distributor at 0º timing, when you put 7º in your app, you end up with 7º total timing. if you use the light and set the distributor at 5º, the same 7º in the app will be 12º. you need to have the base timing correct or it won't work properly (and could destroy your engine).

there are two common strategies for setting up the base timing.

strategy 1 - set base timing mechanically to your desired idle timing and use the 123 only to advance

you can pretend it's like the stock mechanical old timey distributor and use your light to set the distributor (with the engine running at 850+/- RPM and the vacuum line to the distributor MAP sensor disconnected) to what your idle should end up being.

this is normally the only way to go with a mechanical distributor. it seems like the obvious way to approach things with the 123. e.g. if the book says 7.5º , time it to that at idle with no vacuum on it and go.

strategy 2 - set base timing to 0º (or something between your target idle and 0º) and do the rest in software

this way, you set your actual idle timing as an RPM value in the app e.g. 500+ RPM on the "centrifugal" table, relative to your static value. what's interesting about this, is that you can also play with start retard if you want (although a bus with it's obscenely low compression rate won't really need that, but it may make starting easier - YMMV).

but basically, time your distributor to 0º or any value lower than where you "think" you're going to end up. then you can do the rest in software.

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with either approach, it's important to make sure you are setting up the 123 tune software so you aren't getting any "false" timing added to your timing light measurement while you're setting things up at idle.

you don't want the app adding more timing because e.g. your idle RPM on your motor is off, or your settings in the app are not quite dialed in. if the app is adding 3º and you don't realize it, and you time the engine trying to get 8º and think you are doing 8º as your static timing, but in reality are doing 5º...thing will be off.

the best approach is to set up a custom .123 file with your timing all 0'd out to use only when setting your timing with the light. this file would have no vacuum advance and no "centrifugal" advance.

then use your light, physically rotate your distributor, and set the static timing how you want.
then switch back to your real ignition maps.

for your actual maps, here are original VW distributor specs:
https://oldvolkshome.wetwesties.org/ignition.htm

looks like it's a T4, so i assume it may be a 1.8 or 2.0:

Bus & Pickup Late 1976-1978 All States, 1979 Federal * 2000
Timing Set At:: 7.5deg BTDC @ 850-950 rpm (Man Trans), 900-1000 rpm (Auto Trans) w/strobe, vacuum hose connected
Advance/Retard Range: Vacuum: 8.5-11deg Adv @ 7.9 In. Hg; Centrifugal: 8-13deg @ 1600 rpm, 20.5-24.5 @ 3400 rpm

remember, these are the advance values - so your total timing would be those number plus your base timing....

...which is probably 7.5º +/- 1º .. which means you could end up with around 32º advance without any vacuum connected.

i'd say you could take that a bit higher (36º) but i have already listened to people on here whine about it enough to say - don't listen to me, just leave it at that nice conserative 28 - 32º.

your fuel tuning (e.g. AFRs) and octane matter quite a bit in determining what the actual proper value is.

most people like to run them at a totally wussy 28º so maybe try that. (for perceived lower temperature - some might say it's instead wasting HP and just trading CHT for much higher exhaust valve temperatures that they can't read on their gauge...T4 engines are famous for dropping exhaust valves and they are running really lean AFR stock and retarded timing, with owners opting to retard even more...gosh, wonder if there is some causality).

You'll set them up in the app like this:

those pictures should give you an idea, but don't use those values above (unless you really know what you are doing). they were on a 2.0 Jetronic with some base timing, lots of wideband fuel tuning, and are pretty aggressive.

instead, start with the ones based on the book spec and you can go from there. the "correct" way to tune your ignition tables is to use a dyno ("rolling road") and check torque output and achieve "MBT" (look it up, there are great HPAcademy courses on tuning if you want to learn more). the timing should be advanced until you reach the maximum torque value and no more...perhaps tuned on a slightly lower octane than you plan to run, so you have a safety margin in practice. these engines are running really low compression and not really be knock limited like a turbo car, so you will get to MBT before you get to knock. if you do end up on a dyno, take note of the little +/- controls on the live dashboard gauges....you can actually hold the vehicle at a specific RPM on the dyno and use those to find MBT.

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here's a special tip:
off-idle is a place where you can maximize the impact of the 123 and create the total opposite of a "009 flat spot" type effect

one strategy that the 123 lets you do is to kick in a ton of timing instantly the moment you come off idle...which is really nice...stock says an additional 8-13º or so at 1600 .. but the idea is to start giving it that as close to idle as possible .. you will really feel the improvement in responsiveness coming off a stop.

so, you might have your idle at a perfect 800 RPM..and set your base timing with the distributor at 0º...and then put 8º in your RPM table at a super low value (you can also try playing with start retard here by having a lower value <600RPM and your 8º past that)....and then let's say at 1100 maybe you kick a full 9º of additional timing at it, and then 4 more at 1600 so you end up where the book was with 13º. this is somewhere you can play around. notice in my example it also has multiple 0º's in the table to keep it from doing a linear ramp on the values until i want them to actually hit at 1100. there can be some subjectivity and feel here to figure it out.

remember, it's good to be conservative with ignition timing, though....the idea is that the minimum # of degrees that achieve maximum torque is ideal, though.

the 123 will curve between your values, so if you just plug in 8º at your idle RPM and 24º (8+13) at 1600RPM to try to match the book, it will ramp linearly between those values.......... but you may find inserting more points to have things ramp a little faster at certain points (e.g. the moment it comes off idle) can be useful... you can't do that with weights and springs, but you can do it with a computerized ignition map. that's why the initial throttle tip in on new cars usually feels so much nicer and less mushy than an "old car." Notchboy if you are reading this, i think you remember how punchy my automatic bus was off the line....this is why.....
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if you really want the best outcome, tuning the carb and ignition together using a wideband and a dyno could be transformative to the way the car drives. but, just sticking the 123 in there and timing it right, with some vacuum advance, will probably provide all you need/want and should be fine too.

also, you will definitely need to carefully tune your vacuum tables. you may not be able to just plug values into the app based on what that spec says above. ideally, you will drive the car, and run the "Dashboard" and observe the real vacuum signals measured by the MAP on the distributor. maybe the values from the stock distributor will work fine with the Weber. maybe not. more likely yes than no though :) but you should still follow the process.

it's that gauge on the top right. that's your vacuum gauge.
basically, you want to drive around and watch that.
the notable points to observe are idle, off-idle and about 40-50% throttle.
when you get to tuning the vacuum numbers, the idea is that once you mash on the throttle at all, there should be NO vacuum advance whatsoever.... anything past half throttle should probably have no vacuum advance.
so, the goal is to understand the vacuum signal range, using that "Dashboard" tab's vacuum gauge, that you are seeing in operation...and then to use those values to build your vacuum table.
the values on that distributor spec sheet may not match up with your Weber progressive....

i'd say find where your point is where you are driving the thing super lightly...put your max vacuum (11º+ i think is good) at that value, and then find where you are around maybe 1/3 throttle, and set it to a lower value (maybe 8º) , then at 50% set to 0º. going from a non vacuum advance mechanical distributor to a properly tuned 123 with the MAP setup right will be the other area (besides off idle) that you probably notice the largest impact...

make sure you read the 123 tuning manual
https://123ignition.com/manuals/123manual_TUNEPLUS.pdf

i will say this much.. the vacuum tuning is the only part where it can actually get painful. this is where you will probably spend most of your time. the RPM table and physical install of the distributor (with a timing light in hand) are easy. if you study the screen shots, you might notice that my gauge is in inHg but my table is in Abs kPa...that's where things can get hungup...... just getting the right #s in the vacuum column of the table. that's the part that can be painful - the MATH/logic and ending up with the right numbers to type in :) observing vacuum and plugging some numbers in, isn't that big a deal.....but not f'ing up what you key in is harder if you're going from inHg -> kP Abs :)

finding the right values and successfully performing the formula conversion stuff on the vacuum table can be annoying. the key is to make sure you run the car and observe the Dashboard tab...and see how much vacuum you are pulling, and whether you are getting the timing you think you should be according to what you put into the table - take note of that gauge on the top left, it's the actual vacuum advance being added in real time. you should be able to drive at a steady light throttle, learn your vacuum values, then go plug in the right numbers, then repeat your drive and see your advance vs vacuum on those top left vs right gauges change to match what you expect. then you should be able to increase the throttle a little bit and see the vacuum induced ignition degrees drop lower, and also go WOT and see them go away completely. it can make things a little easier if you run a temporary simplified or "locked" RPM timing table while you get your vacuum points dialed in....that way you are isolating to a single variable for your total advance gauge.

it's very easy to mess up the vacuum table value conversions going between inHg <-> absolute kilopascal, if that's how you're doing it...i believe that the 123 guys (based on my whining , perhaps, lol) finally added the ability to change units on the vacuum gauge itself in the dashboard tab, so that you can see values more easily turned into inputs for the vacuum table...but not sure, havent been using the 123 since that update. they may have made things easier in the math department with that last tweak.

also, of note, you want to make sure you set the minimum RPM value correctly on the vacuum table. you don't want it coming on while you are at idle. so set the "Starts @ RPM:" value correctly.

keep in mind, that your carb's idle setting...and any fast idle/electric choke stuff that may apply...are important to understand (mostly what RPM they are at, and whether any choke is on/off and how that interacts with your tables) and can interact with your tuning. make sure that you know what's happening and that your standard (e.g. warm) idle speed isn't set too high, and your fast idle mode is still happen when you're done tuning.

yeah, i know i probably just dumped an overload of information. sorry. basically, if you connect the hose and set your base timing with the light with the maps 0'd out, then put in the RPM & vacuum advance values to match the VW spec sheets (that OldVolks site) - you will at least be starting from the point you would be with a stock distributor. there are some VW maps 123 provides, but i don't remember them being all that great.... anything you will will be better than a 009, though :)

Mon Aug 28, 2023 12:06 pm

your engine bay looks spotless, nice, dont have a 123ignition but have heard they are much better build quality than the pertronix.

I tried a pertronix 3 in my bus with the proper coil, the proper specialty plug wires it called for and got really bad irratic idle timing with it that i could never get to smooth out. Im assuming there was some electrical gremlin possibly related to grounding or having other things like a tac attached to the coil but i know they can just have a bad module as well.

i got a german bosch svda dizzy rebuilt and it runs like butter with that in there. if i were to go electronic i would get one of these. Not sure id ever trust a pertronix unit ever again!

Mon Aug 28, 2023 2:57 pm

So why isn't there a thread where people can have their engine setup and the map for this 123?

I'm not familiar with this device but -- broadly speaking in order to get the point across -- if it has a file (.123 file?) or list of settings that a person can input to pre-map it so there's a solid baseline (use it as-is or else modify it afterwards) then it would immensely help the community to document this. It would make life so much easier, particularly for those who have a bone-stock motor since there would be no variance to worry about.

Mon Aug 28, 2023 3:53 pm

Air_Cooled_Nut wrote: So why isn't there a thread where people can have their engine setup and the map for this 123? … It would make life so much easier, particularly for those who have a bone-stock motor since there would be no variance to worry about.

I don't know anyone with a bone stock motor that wants to throw $600 at their distributor to program it from their smartphone… :P

Robbie

Mon Aug 28, 2023 4:16 pm

airschooled wrote: Air_Cooled_Nut wrote: So why isn't there a thread where people can have their engine setup and the map for this 123? … It would make life so much easier, particularly for those who have a bone-stock motor since there would be no variance to worry about.

I don't know anyone with a bone stock motor that wants to throw $600 at their distributor to program it from their smartphone… :P

Robbie
a totally stock proper NOS SVDA from VWOG only cost $119 shipped when they had them for my bus. As Robbie says, why would someone throw so much money at a non-problem. All the distributor does is light the fuse. If it is working right, someone getting high tech to light the fuse doesn't do anything for power or performance. The same amount of fuel and air is burned, making the same power. VW worked out the timing when the engine was designed, and put it into their stock distributor. If someone wants a map to program by then start with that curve. FWIW we used to dyno engines for the race cars. As long as one stays below detonation or way late timing, there is very little difference of power over a couple degrees of advance.

Mon Aug 28, 2023 9:34 pm

SGKent wrote: why would someone throw so much money at a non-problem.

Ah, the beauty of hacking and exploration - it's not about fixing what's broken but about discovering what could be. Spending $500 on a distributor programmed via smartphone isn't frivolity; it's a modern manifestation of age-old curiosity.

Sure, the original VW distributor might be a well-crafted piece of machinery. But who's to say it can't be better, or at least different, in a way that adds nuance to its operation?

In the eyes of an explorer or hacker, there are no 'non-problems,' only realms yet to be charted. It’s not about necessity; it's about the thrill of the possible. And that, my friend, is priceless.

Mon Aug 28, 2023 10:07 pm

i'd love to be able to 'adjust' my timing for say altitude or octane..
perhaps a few program variables and a click button would be nice.

anyplace to put a knock sensor that could help maximize timing efficiency?

Mon Aug 28, 2023 10:38 pm

yeah right. I suggested the other day a smart phone app for mileage in lieu of a trip odometer and lots of you said no more smart phone apps, y'all said you were done with them. Changing to a aftermarket distributor, electronic with a smart phone app or not won't do a thing for engine power, smart phone app or not.

Tue Aug 29, 2023 12:52 am

There's some really good information here, I've got one of these sitting on the bench waiting to fit once I get other jobs finished. I'm certainly not a big fan of apps but being able to see what's going on in realtime is a plus.

Wonder if a sticky on the 123 Tune would be useful? It would be handy to see how curves compare, particularly for those with non stock setups.

Tue Aug 29, 2023 11:09 am

The relative humidity and air density can improve the engine performance more than playing with the factory timing map ever will. A 35 year old who puts a $600 purchase on his credit card will pay $1,699 for that $600 by the time it is paid off. But a 35 year old who invests $600 at 7.5% will have $5,652 in his account when he retires 30 years later. The difference is $7,351.

Tue Aug 29, 2023 4:53 pm

SGKent wrote: The relative humidity and air density can improve the engine performance more than playing with the factory timing map ever will.

Lol, that’s just plain wrong. In so many ways.

The 123 vacuum distributor is the single most important piece of tuning equipment available for buses today besides a pre-cat wideband O2 sensor.

You can grab 5-10hp easily for short trips and puttering around town. Then flip a switch and go back to a stock “safe” timing map for long road trips with camping gear.

You can make a map with higher idle timing for AC compressor loads. You can make a smog map, DD map, and race map. All from your front seat. Instantly.

It’s just not a good financial investment for someone with a true bone stock engine. Their money would be better spent on a road trip.

Robbie

Tue Aug 29, 2023 5:40 pm

airschooled wrote: SGKent wrote: The relative humidity and air density can improve the engine performance more than playing with the factory timing map ever will.

Lol, that’s just plain wrong. In so many ways.

The 123 vacuum distributor is the single most important piece of tuning equipment available for buses today besides a pre-cat wideband O2 sensor.

You can grab 5-10hp easily for short trips and puttering around town. Then flip a switch and go back to a stock “safe” timing map for long road trips with camping gear.

You can make a map with higher idle timing for AC compressor loads. You can make a smog map, DD map, and race map. All from your front seat. Instantly.

It’s just not a good financial investment for someone with a true bone stock engine. Their money would be better spent on a road trip.

Robbie

You don't "grab" 5-10hp. If you are able to gain 5-10hp on a small air cooled VW engine several conditions exist:

1) your engine is already in a state of being mis-tuned, mis-fueled or both.

2) HP is torque x RPM. To get an increase of 5 - 10 HP on a small engine at a given RPM then you need to be able to burn more fuel and air to create more torque. If you burn more fuel and air then one has to back off the throttle or the result is an increase in RPM because the load is static. If you increase the engine displacement or increase the induction pressure (hence reference to altitude density which is elevation, barometric pressure, temperature and humidity) you get more torque. Or you can rev the engine to a higher RPM. Both ways you get more HP. Usually RPM change is accomplished with gearing, or a top end improvement with induction, exhaust and compression at max timing allowed pre detonation. It is not accomplished by playing with timing a degree or two unless as I already stated, your engine is out of tune. You are either burning all the fuel and air in the cylinders or you are not. To be frank, VW put many years of research on engine dynos choosing the best map for your engine based on load and RPM.

3) What you are describing at a static RPM is a gain in efficiency, and a 5-10 HP gain would be a 10 - 15 percent gain in efficiency at a given RPM. Since the discussion is always about POWER and not about MPG, it is safe to assume you are selling POWER and not efficiency. Since you are selling power, it is safe to assume snake oil lubricates it.

I am leaving now and going back to real engine building, performance, and science. This psuedo science is a waste of my time.

Tue Aug 29, 2023 6:37 pm

The barbarians at the gate are the establishment now.

And there are new barbarians at the gate.

Wed Aug 30, 2023 4:05 pm

airschooled wrote: The barbarians at the gate are the establishment now.

And there are new barbarians at the gate.

I saw one of these, and figured you would like one to gap plugs for the extra performance and HP. Summit has them. It is not I who is the gate keeper for the establishment. Last I heard you were pushing EV engines as the great solution for saving the world. How come you still need a distributor?