www.MSgroups.com read only forum (Jan.15,2018)

Has anyone done much with ignition tables? I have a table in there but it seems to be giving me some grief. It's hard to describe but the engine shudders in certain areas of the map, opwer drops off when that happens. In other areas of the map where the shuddering clears it seems much more crisp.

I started with a spark map that was similar to a factory distributor curve and then started making some adjustments.

If the car is shuddering you might try pulling the timing back a bit in those areas, especially if it is in the cruise (lean) area of the map. If that doesn't work you can always take it the other way. Save your spark maps as go with a little comment at the end to help identify them.
eg. 20_4_2011_high_missfire

At least what I've started with is half decent, and it' drivable.

I'll have to con someone in to driving for me while I try to tune on the laptop.

Thanks!

Damo.

Metalfab_101 wrote:At least what I've started with is half decent, and it' drivable.

I'll have to con someone in to driving for me while I try to tune on the laptop.

Thanks!

Damo.

Getting permission from management to spend hours driving around chewing fuel is the problem for me.

I once had the idea of making a controller with an interface board to a laptop to tune while diving.
One button could take you to the current map position then use a potentiometer or buttons to increase/decrease fuel/ignition/AFR in the open map, and another button to burn the values.
One possible board would be a teensy http://www.pjrc.com/teensy/ or maybe an Arduino.

Maybe I'll build it one day...
I'll get a few other projects done first.

Another option is to hire a Dyno for a couple of hours. There are a lot of shops around that will hire you there dyno. usally under $100 per hour plus maybe a little extra for them to show you how to use it. That would be the best way to tune it.

Otherwise just make small changes at a time to the trouble areas. If your trying to tune by yourself, just datalog and hit spacebar to put a mark in the log so you can see where the problem areas are.

Cheers
Daniel.

Hey MetalFab
I know this thread is a bit old now, but I've been agonizing over the same issue with my 186. I started with the factory curve published for a high comp 202. It was all I could find. Runs well, but paranoia has had me pull some timing due to what I think might be pinging, although these noises are hard to isolate when youre hurtling along at speed in a 50 year old car. I found a dyno bloke near me who specializes in Holden inline 6's, and have an appointment with him next Friday. I'll let you know how it went, as I've never had a car dynoed before. I know you're nowhere near Melbourne, but I thought many would be interested to see the before and after for the spark map, and those others who have similar motors might benefit from the "after" especially. More to follow...

Definitely keep us posted!

I read a book recently that suggested some motors can handle upto 45degrees at light loads! I'm keen to try that on the Falcon since it's only doing about 1100-1200rpm at 60 in (overdrive) fourth : with very small throttle openings.

OK Fellas,
Today was the big day. Drove into the dyno place and described the setup to Anthony, the operator/tuner/technician. Despite having never seen (or even heard of) the MS system, he was most interested in the setup. This bloke is one of those guys who are passionate about what they do, and it shows in their approach to their work, to the point that to them it's not "work". We started with the fuel map, first light, slow, then working into higher and increasing loads. He took his readings from a CO meter, and described to me what the targets are as we moved through the cells and I got the hang of the delay factors involved. Also, my WB readings were pretty much spot on! Then onto ignition table. Wow! I was a real chicken here. After some time here, again working up slowly thru slow/light to fast/heavy, the timing advance came up by 16 degrees! I explained I'd rather fix heads than replace pistons. Some to-ing and fro-ing between fuel and ignition maps, just a tweak here and there now, and that was it. Time for a test drive. I went for a 20 minute drive which involved 10 mins on the freeway, then some "normal" traffic stuff. Holy tap-dancing <'your deity here'>! Never had an FB "Nose-up" at the lights. I thought this thing ran well before, but now- wow!
So in answer to the timing question; yes, a dyno is a great way to get the timing (and fuelling) right. This is only half the story, a good tuner who has the patience to familiarise himself (or herself) with the fiobles of your system, as well as the skills and experience to know a well tuned donk when they see one, is more important.
Oh and my speedo is right on the knocker, too! Now just to clarify,
This is a 186 bored out to 192
Flat tops (about 9.4:1 S.C.R)
Stock camshaft.
I would never recommend anyone just drop these into their Holden 6 setup, but rather just see the differences (especially in the ignition table).
Again, dyno time is money well spent!
I hope this info is helpful.