Ignition only table?

[andy198712]

Hiya.

Just got my edis working as stand alone today (great feeling!)

I've got ms1 2.2 with extra loaded, edis settings are on it. But what sort of ignition map do I want?
It's a 1200 single port and 30 pict 3 carb

Cheers guys!! (and ladies)

[andy198712]

given that when i drive, the main part of this driving is between about 1250-1500 and 3000 rpm (3k is normally a fast cruise about 50-55mph)

the engine doesnt really rev past 4k much, although i've left a bit of extra for a safety margin. here's a basic map i've adjusted the rpm ranges on.... your thought?

[Clonebug]

given that when i drive, the main part of this driving is between about 1250-1500 and 3000 rpm (3k is normally a fast cruise about 50-55mph)

the engine doesnt really rev past 4k much, although i've left a bit of extra for a safety margin. here's a basic map i've adjusted the rpm ranges on.... your thought?

How much boost are you running???

You should be able to carry the 30-32 degrees all the way up to 100 kpa or higher.

140 kpa is around 6 lbs. according to the my calculations. You should be able to run upwards of 24-26 degrees easy.

Check to see what your IAT's are... that is going to tell you how much advance you can run.

you should be able to have full advance at 2800 to 3000 rpm and then ramp it up evenly from idle to the 2800 rpm.

I change my advance quite regularly to test what the engine wants. Take it out and drive it and have someone bump the advance up in your light cruise ranges just to see what the engine does. You will be able to feel it and if the engine likes it you will be able to maintain speed with less throttle.
In order to gain the most you will need to lean it out in the same areas though. I have run as high as 38 degrees for a while at cruise to see what happens.

It would be best to have a good muffler on so you can listen for detonation while testing.

[andy198712]

Cheers for the info, i'm guessing this is more of a boosted map then...?

my engine is NA and stock Solex 30 pict 3 carb..... should i drop the kpa?

Thanks you!

[Jadewombat]

The kpa range looks good, I run a similar set up with a 34 PICT carb., 1.25 rockers, and a good exhaust on a 1600 engine. You could be a bit more aggressive with the spark across the board.

[andy198712]

Thanks bud that's a great help.

I see you got some pretty high advance numbers, guessing that's ok but why do dizzys only ever give u like 30 odd degrees then?

And is the kpa amount effected by throttle opening and load?
Or example, foot to the floor up a hill will be high kpa.
Cruising with minium throttle is low kpa

Is that right?

And you can give in more advance at cruising yh? What does that gain?

Thank you!!

[Jadewombat]

You're able to do more advance because it's a more efficient burn and you're taking into account the MAP pressure. Your kpas should increase when you stomp the gas, then gradually taper to a lower value as you get up to speed.

[andy198712]

You're able to do more advance because it's a more efficient burn and you're taking into account the MAP pressure. Your kpas should increase when you stomp the gas, then gradually taper to a lower value as you get up to speed.

Thanks buddy!

i might just copy your map but tone it al down a tad to start then work my way up. if you dont mind

[supaninja]

If you don't run enough timing your heads will get hot as shyt.

from 2500 to 5000 do it like this:

100kpa 30 (later on you can try out 31 and maybe 32)
90kpa 35
80kpa and down 40

that will get you in the ballpark, then you will need seat time to see what the motor likes, you have to be a bit of a car whisperer to really dial in timing. As bear in mind is you dial it in on super unleaded you should continue to use it, if you dial it on low grade unleaded then you can use whatever you want.

[andy198712]

Thanks buddy, really helpful.
So is 100kpa full throttle for an NA engine then?


Good point on too little timing, I thought it would be "safe" but now I know

It'll all be on our UK 95 Ron standard fuel. Which is the lowest we have.
I think it's something that will just take time, I'd like a CHT gauge too so I can keep an eye on my head temps!

I'll change the. Ap tomorrow and give it a go and report back

Thanks!
First time doing any of this and there's not a great deal of ignition only info with carbs but this forum has been very helpful!

[supaninja]

Ya 100 KPa equals atmosphere (at sea level), which is WOT on a NA motor. Part of the ign tuning process is knowing where is motor is when you are cruising so you can dial down a little bit of timing when you give it a little gas to go up steep hills. Normally with EFI you would add a little fuel at the same time, but with a carby that is not so simple. You really need a wideband O2 sensor so you know for sure that your not too lean anywhere. The numbers I gave you are fairly conservative, and 95 RON is about 91 octane so you should be plenty safe.

There isn't a lot of info on this stuff since it is very engine specific, and a bit of a black art. Some seat time and a good ear for your motor will tell you if you're improving things. Since your motor is a stocker for the most part, it should be super easy to polish up the tune. Keep track of your fuel mileage, I'm a bit curious how much it improves with just a ignition setup. My guess is it will definitely be noticeable, driveablity should be improved as well. Keep us updated.

[andy198712]

thanks mate! very helpful!

so in cruise i want to have a little more advance right? ie when you say dial down, you mean add a bit more yh?

this is my map


WOT for me is 90kpa and it holds in there steady as i floor it (ala the red numbers, which were 35 but i knocked them back a tad)

where the dot is on the left is where i'm idling at though..... is that right or should i be idling at low kpa? as when i give it a litle throttle the kpa then drops to low levels?

is that because my vac port is above the throttle plate?

Thanks! having a great time and great sense of achievment!!

i already notice i'm using alot less throttle at cruise and pulls cleanly!!

[andy198712]

oh and i've never checked the MPG before.... mainly as it would depress me but on a rough check i'm 22-28mpg UK will recheck in a while to see what i'm doing on MS

[supaninja]

Sounds like you are using the ported vac port, you want to use a regular vac port so anywhere on the manifold will give you a true vac signal. Idle should be reading a lot lower KPa. My MS reads 97KPa at sea level and I don't get 100 at WOT either, just set the map up accordingly. I'm glad to hear it's pulling cleaner Ignition is a very overlooked part of the tuning process in the AC world, I believe it's the most important part.

[andy198712]

Sounds like you are using the ported vac port, you want to use a regular vac port so anywhere on the manifold will give you a true vac signal. Idle should be reading a lot lower KPa. My MS reads 97KPa at sea level and I don't get 100 at WOT either, just set the map up accordingly. I'm glad to hear it's pulling cleaner Ignition is a very overlooked part of the tuning process in the AC world, I believe it's the most important part.

cheers

yeah i think our right, i'm using the one on the carb, just ordered a 4mm brass fitting to tap into the manifold so will report back when thats fitted.

pulls so much better, 30-50mph is alot smoother and stronger i feel, no flat spot or hesitation ect

in the 1500 and 1800 columns, do i want more advance at lower kpa do you think? instead of it staying the same or tapering down, should i slow taper it up? for lower rpm cruising ect

as you say, hugely over looked i think, people who run hipo engines and use stock dizzys dont know what their missing!

Thanks