Xu9ja Distributor Advance Curve

[opticaltrigger 52]

Hi guys,

Im at a point on the project where I need to start thinking about programing a timing advance curve for the ignition system and I was hoping one of you guys out there might have a copy of such a thing for the standard 1900 GTI distributor which I could look at.

The other thing which crossed my mind was,and it's purely out of interest.

Back in the day when Turbo Technics were offering kits for the 205.How did they,if at all,modify the advance curve when the motor went into boost.I can only imagine that the kit came with a distributor which had different springs on the bob weights.Maybee somone has a copy of that curve also?

 

Any info you guys can shed on it for me will be a real help.

Many,many thanks and all the best

O.T.

[DamirGTI 343]

Try searching , as i remember that someone posted graph for 1.9 dizzy here or for both the 1.6 and 1.9 as well ..

 

As for recurving job , try asking this guys i'm positive that they have solution for your particular engine spec : http://www.h-h-ignitionsolutions.co.uk/

... but do phone them instead of sending e-mails as you'll hardly get reply back - they're too busy for writing e-mails .. also , dizzy recurving job was around 20/22,00 quid + postage ..

 

Damir

[jackherer 543]

The Turbo Technics 205s had a modified vacuum advance unit that retarded on boost as well. AFAIK the distributor was standard other than that.

[opticaltrigger 52]

Thanks for the reply Damir & Jackherer,

I tried doing a search for the standard advance curve but I could'nt find one anywhere at all.Any ideas on how to locate the post would be great Damir then I can take a detailed look at it,failing that and I could try Bosch but trying to get blood from a stone is easier than information from Bosch.

 

Thanks for the info on the Turbo Technics Jackherer.Yes I see now with the diaphram for retard.I have seen them but Im going to do it electronicaly with this one using time based commands in a microcontroller.I could start from scratch and plot my own graph for the on boost timing retard but to have a look at some existing ones would cut down development time dramaticaly.

 

Thanks again guys

O.T.

[DamirGTI 343]

... been searching for the topic but i simply can't find it will try some more "digging" .. anyway i'm 100% that i've seen graph for dizzy advance here though , the topic might be lost/deleted etc. during the last database crash

 

Damir

 

EDIT : found something :

http://forum.205gtidrivers.com/index.php?s...&hl=advance

 

.. but there was more of this advance graphs

Edited February 24, 2010 by DamirGTI

[opticaltrigger 52]

Thanks for the help Damir,

The graph is really helpfull.I'm taking the shaft rotation speed and doubling it to get to crank speed and I'm assuming that you must need to do the same with the degrees of shaft rotation figure to get to degrees of crank rotation,being that the distributor runs at half crank speed.What do you think Damir,does that sound about right to you?

Edited February 24, 2010 by opticaltrigger

[DamirGTI 343]

Sorry i can't help , i'm crap with this mapping/plotting stuff

 

Our man from "the land down under" - PeterT , will be of much better assistance regarding this issue

 

Damir

[opticaltrigger 52]

Thanks all the same Damir,very very helpfull.

Having looked at it again I think the two sets of parallel lines perhaps could be degrees of tollreance within the distributors but it's just a guess though.

I will try and catch Petert as you sugest and get his thoughts for some clarification on the matter,if he dosent see this first.

Once again,thanks for the help Damir.

 

All the best

O.T.

[petert 591]

The graph is at camshaft speed so you need to double both degrees and rpm. The two parallel lines on the left are the dizzy with and without vacuum, absolute values. So if the dizzy was set to 10 deg. BTDC static, the maximum full load (no vacuum) advance would be 30 degrees.

 

At 3000rpm (crank), maximum vacuum, again set to 10 deg static, the advance would be approx. 31 deg. (10+(10.5*2)). Similarly for 2000rpm. Thus why they ping like a bastard with a bit more compression.

Edited February 24, 2010 by petert

[opticaltrigger 52]

Excellent, thanks Peter.

That does make sense,and its interesting to see how the graph slips down into the negative very slightly at around 1000 RPM (crank).The other set of parallel lines on the right is still a little confusing but nontheless the graph and info is very helpfull guys,so thanks to all of you for the help.

Very best regards

O.T.

[petert 591]

Only guessing, but I'd say that's an independent test of the vacuum module, thus the scale in millibars.

 

What sort of engine and ECU are you going to program?

Edited February 24, 2010 by petert

[DrSarty 90 1 Cars]

What sort of engine and ECU are you going to program?

 

It's an inter-dimensional worm hole traversing vehicle....or perhaps it's this one.

 

Either way they both seem very complicated.

 

Hats off to this chap for doing something different though, and I hope it works out.

 

He has a dog called OpticalTrigger too.

Edited February 24, 2010 by DrSarty

[opticaltrigger 52]

Hi guys,and thanks for the link Sarty.

It's just my own plan really Peter.Thought I'd start from scratch with the managment and see what I could do.

It's a great hobby project to be doing really and plus I get to learn a bit on the way.

 

As I put in the project section,I've never really thought much of the ECU as much more than a filing cabinet full of ideas on how to run an engine with a calculator in one of it's draws.The hardest part I find is when you have to convert distance traveled into time taken so it can be programed into a microcontroller.

I was just looking at it through the link Sarty put in and I read your post Peter.Yes,I cant disagree with you Pete and although I havent updated it yet I have moved away from the reliance on the cam driven triggers for the same reasons and also because of boost timing reasons,necesitating the use of a flywheel sensor which is conviniently allready there,but I will put a detailed explanation of it in the project thread.

 

Once again thanks for the input guys and if your working at the mo Sarty take care and mind how you go mate.

All the best

O.T.