Timing mods

[smallcox]

A little help needed Gents,

I have a mission to build less advance in my distributor after my dyno session. Does anyone on here had any work to tailer there advance curve. I quess what I am after is stronger springs to slow down the rate of the advance curve, (are they avalible).
When tuning cars you can normally buy several springs at different ratings to do this, I also no that by adding a dab of weld to the stop pins then filing them back will also increase/decrease total advance it's just the springs I require.

HELP

[bis13]

can you try an electronic dizzy and see if that improves it like a 123 which has several different preset curves?

[smallcox]

This will not work as I have boost retard fitted for the turbo. If springs are not avalible then I might try fitting two springs each side. Bit hit and miss but I beleive that at present full advance is reacted at 3000rpm aprox and I require 4700rpm before full advance

[Pete126]

Try shortening the existing bob weight springs one coil at a time and check

[GTMaster]

You could try springs from other Fiats (850,124,125,127,128) or ones with Marelli distributors. I think the 124,125 distributors are similar if not the same...

[GTMaster]

Ok, this is what i found in my book on ignition advance:
Fiat 500: 3000rpm approx. 20 deg
Fiat 850 Coupe: 4500rpm approx. 40 deg
Fiat 124: 3500rpm approx. 20 deg
Fiat 125: 4250rpm approx. 24 deg
Fiat 128: approx 4500 rpm approx. 28 deg
Thought i'd list Fiats since parts are usually interchangable. (Haven't read ignition timing graphs in ages so hopefully what i listed is somewhat real  )

[DEYAN IYI]

Maybe Megajolt - once and forever.

http://www.hvd3.it/ITALIANO/FIAT500/KIT_acc_prog.htm

[smallcox]

Cheers for the info,

Pete, yes thought about that one and also lightering the weights themselves.

Gt Master, interesting to see the assortment off dizzys for fiats but I have no spare parts from these models unfortantly

And yes Deyan iyi the Electronic ignition would be the best way as 3D mapping would evolve the 126 engine but at a cost

I think a bit off everything might work, having a go tommorow once the wifes chores are done. , and a friend off mine has lent me a timing light.

[ape20ff]

Hello.
A trigger wheel 36 theet.

http://www.webalice.it/piccolopiccolo/ruota_fonica_36.DXF

Bye.

[rbl64]

Hi,

I have bought a 123ing dizzy for this exact reason.
I was thinking 1deg retard per lb of boast at full advance from standard full advance. Achieved by selecting a short advance curve, this should give a reasonable advance at idle and low rpm pre boast.

I will let you know how i do. i am just starting the fab now.

Hope this helps I look forward to reading what others think.

[michaelodonnell500]

To try the stronger spring you could contact this place:

http://www.leespring.co.uk/uk_index.asp?CountryCode=011

rather than measuring the spring length, wire diameter spring rate and knowing the material, you could ask if you could send one in and have them asses it.
I have done this in the past with a company called James Walker who manufacture o-rings. They were able to perfrom a destruction test on it to determine the shore hardeness and suggest an off the shelf alternative
Then you could order a variety of slightly stronger springs and find out what works. It will involve a bit of trial and error, but most fiat issues usually do!