does any know what kind of results i would get from putting a carby distributor on a turbo motor (apart from the lack of knock senser)

 

what i want to know is what sort of retard i would get under boost......i figger if it advances under vacuum then its got to retard under boost

 

do the turbos with a vacuum disty have a differen't vac unit... i.e like the early mazda distys with two hoses going into them

you can find 4wd, and 2wd distributors from na mpfi motors. they have the two vac hoses. or you can get a disty from a carb, with only the one vac line.

 

more advance, when it sees no vacume, so that means when you hit boost, your at full advance. which is cool, if you have everything else tuned right =]

the result is ok; been running the standard hitachi dizzy for years; I had the static timing at 10-12degrees tho:slobber: , as I didn't know that the static timing for the ea82t is supposed to be 25degrees!! But at least I didn't seem to have any pinging problems and standard unleaded, maybe the response wasn't so good from start, but once its reving and goin in boost the power does really come on - bit confused how this ties up with whats happening with advance in this case?

trying static timing of 20degrees atm - around town its great, up the mountain, high load, hmmm not so sure..started to get some ping so backed off.

more advance, when it sees no vacume, so that means when you hit boost, your at full advance. which is cool, if you have everything else tuned right =]

 

hmmm full advance under boost.....is that like 20deg static + 20deg mechanical/vacuum advance = 45deg btcd under full boost?

 

don't know if i like the sound of that....

 

good thing propane is 104 octane

IIRC 1987+ all the distys are the same....two diff PN's but basically the same item.

 

1985-early 1987...a train load of distys to choose from.

IIRC 1987+ all the distys are the same....two diff PN's but basically the same item.

 

1985-early 1987...a train load of distys to choose from.

 

the disty i have is off a carby ea82 85-86ish

hmmm full advance under boost.....

 

Nah, you should have no advance during boost, the line going to the vacuum diaphragm will have boost pressure, so the advance unit wont move at all, unless you have a diaphragm off a turbo on it.

Nah, you should have no advance during boost, the line going to the vacuum diaphragm will have boost pressure, so the advance unit wont move at all, unless you have a diaphragm off a turbo on it.

 

why wouldn't it move...if it moves one way when it has negative pressure on it surly it would move the other way when it has positive pressure on it?

why wouldn't it move...if it moves one way when it has negative pressure on it surly it would move the other way when it has positive pressure on it?

 

It may retard the timing, but it may not have any room to move that way, im not sure.

does any know what kind of results i would get from putting a carby distributor on a turbo motor (apart from the lack of knock senser)

 

what i want to know is what sort of retard i would get under boost......i figger if it advances under vacuum then its got to retard under boost

 

do the turbos with a vacuum disty have a differen't vac unit... i.e like the early mazda distys with two hoses going into them

 

The vacuum units are different,but not much in actual advance specs.

Turbo vacuum diaphrams only provide 3* of retard under full stock boost.I seem to recall that non-turbo units also

have enough movement available to provide some retard under boost.I didn`t measure,but,they seemed similar.For a while,I was considering using one on a turbo dizzy(arm is too short)

 

The difference in turbo and NA dizzys is more in the centrifigual advance curves.Turbos advance more slowy reaching full 10* advance at 2800 rpm while the NA is fully advanced at 1900 or so.

You could slow the advance of the NA unit by installing stiffer advance springs or lightening the weights.

Then again,the extra octane of LPG might match nicely w/the quicker advance.

 

An 85-86 MPFI dizzy would allow you to retain the knock sensor.