Ignition retard with carbs?

[Warren]

For a blow through carb what are you guys doing to pull timing? or how many of you are locking timing? I'm looking for an alternative to buying an off the shelf ignition box. I want to make something mechanical and learn from it!

I was thinking about trying to make my own vaccum advance/boost retard diaphram. I have HEARD of a few people doing them, but I have never actually seen one. Alternatively I had though about changing the spring stiffness or preload to make the stock vaccum advance diaphragm retard timing while boosting.

input?

Thanks, Warren.

[corolllin]

lock your dizzy. you wont need to have timing advancement

[corolllin]

yo and get on this page. its a bunch of cool people and oldschool cars.

facebook.com/groups/oldscoolcarcrew

[Warren]

Yeah I'm not big on locking the dizzy.

[NME308]

lock your dizzy. you wont need to have timing advancement

So how do you propose the gentleman is going to retard the timing under boost?

While I know the usual solution is an MSD or ECU to control timing the OP wishes to create a diaphragm style device such as the factory Toyota system on the 3TGTE.

OP: Your mechanical solution is certainly doable but will take some effort to fine tune the spring load vs diaphragm size to gain the timing retard at the correct rate etc. You may also find that it will retard from the first pound of boost and for myself I find that style of control annoying. Since I use rather low compression I like to be able to program the timing retard to only start from say 10lbs boost although you may also be able to come up with a bleed pill or similar to achieve what you wish!

Cheers,
Jason

[Warren]

MS paint "art" at work.



I have the same fears about dialing it in. I figure you could set it up off the car with a hand held vacuum tester pump thing. Just calculate how how much throw changes the timing, then adjust the preload on each side of the diaphragm.

[toyotero2dend]

hey guys I saw a picture ..some one made the dizzy adjustable
they made a hole at the end of the vaccum and welded a bolt to the piece
that makes the dizzy retard or advance and with a 2 nuts on the bolt they
adjusted the timing .
im using a locked dizzy with a msd boost master behind it

[Toyota1515]

You guys drawn in a glass of water, it is as easy as this steps here!

Lock dizzy, and set it up for advanced operation at normal boost




MSD 3 stage retard control with the MSD 6AL, and adjust accordingly for high boost, 2 step, start, of out of the hole operation.

[mikealike]

You guys drawn in a glass of water, it is as easy as this steps here!

Lock dizzy, and set it up for advanced operation at normal boost




MSD 3 stage retard control with the MSD 6AL, and adjust accordingly for high boost, 2 step, start, of out of the hole operation.

HAHAHA Timing retards, whats that

[BOBLOOK]

HAHAHA Timing retards, whats that

Retards