Hi I am not much of a poster as most of the time a bit of reading answers my question but I'm still stuck.

So my question is what is the best and also most cost effective system to use on a suck through turbo set up?
If it has been answered point me in the right direction.

There is a few ways of doing this so I have read but all have there pro's and con's but the few I have been looking at still have me thinking

#1 have a s2bb electronic dizzy sent to have it re-curved. Seems to be cost effective but does having this done only change the rate in witch it advances and not its total advance?

#2 running a twin point dizzy and switching to the retarded points via a Hobbs switch at a certain pressure is reached.
seems like a very good idea but I need more detailed info.

#3 buying the jaycar ignition kits and hand controller but I'm no wizz when it comes to this stuff but could certainly build it and install it but seems to be a bit of a pain and not sure if they work really well?

#4 buying an MSD boost retard unit but they are quite pricey and from what I can tell you still need to buy another unit from MSD to work along side this unit which just adds to the money burning.

Any help would be appreciated or any other ideas or places that can supply me with a good set up?

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=============DATSUN 1600, NOT JUST TRANSPORT FOR YOUR GRAND MA================

First thing is to find a 180B twin point dissy. late 75/76

Then check the std wiring set up of these in the shop manual.

Recommended cheap boost retard for blown L series.

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A little knowledge is a dangerous thing.
www.datsport.com

"R.I.P. Baz. 29 April 2022. Thank you for all your contributions to the Datsun community over the years. You will be missed." - OZDAT

Any one have one laying around how hard are they to come but and how much are they worth?

Do you have one in your shop baz and any detailed info on how to set this up?

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=============DATSUN 1600, NOT JUST TRANSPORT FOR YOUR GRAND MA================

theres 1 on ebay in the US,
I have 2 but one is lost in my collection somewhere,and the other is a mallory unit which i will be using soon

_________________
68 510 - soon to be restored into a replica 68sss
69 510 - current build - L20b turbo
91 GT turbo legacy
GET THAT DATSUN DIFFERENCE!

_________________
68 510 - soon to be restored into a replica 68sss
69 510 - current build - L20b turbo
91 GT turbo legacy
GET THAT DATSUN DIFFERENCE!

Thanks.

Can anyone ex plane to me on how the twin point set up works in relation to a boost application or show me how it is properly set up?

This is all new to me and the first time I have played with an ignition system but I'm learning

_________________
=============DATSUN 1600, NOT JUST TRANSPORT FOR YOUR GRAND MA================

Sorry we do not have any.
Usually they are not worth much as fitting a std dissy to a late 180B will improve fuel consumption & performance.
They are designed as an emmission control device by retarding the ign when certain conditions are met.
These dissys have two sets of points, by switching from one set to the other changes the ignition timing.
In a turbo application, the advanced points would be in operation under low boost conditions.
When boost( at a set point) is applied the hobbs switch( pressure switch) activates a changeover relay.
This relay switches the advance point to the retard points & retards the ignition a set amount.
The amount of retard is controled by the setting of the retard points.

_________________
A little knowledge is a dangerous thing.
www.datsport.com

"R.I.P. Baz. 29 April 2022. Thank you for all your contributions to the Datsun community over the years. You will be missed." - OZDAT

Sorry Baz I Just read up on the Datsun twin point system and how it works should of done this first, I thought they worked like a Mallory twin point dizzy.

Hears the info I found if anyone else wants a read

http://www.autozone.com/autozone/repair ... 5280082ddd

Now it makes a lot more sense and seems to be simple and effective way to work this with boost.

Next few questions I have are to do with tuning.

How much advance do these dizzy's have and at what RPM do they reach full advance?

Should I run the vacuum advance?

How do I know how much timing I should be running? The engine is just a healthy standard L20 with U67 head (for now) with a suck
through stromberg 175, air research to3 set to run 9 psi

What pressure the hobs switch should change to the retarded points?

It says the points are 7 degrees apart but I'm guessing I should be able to change this by playing around with point gaps

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=============DATSUN 1600, NOT JUST TRANSPORT FOR YOUR GRAND MA================

cheers baz and hotdat for that info,helping heaps
time to dig through my dizzys i think
vacum advance i would be guessing should be fine hooked up as it should only advance under vacum then it realeases back under boost

_________________
68 510 - soon to be restored into a replica 68sss
69 510 - current build - L20b turbo
91 GT turbo legacy
GET THAT DATSUN DIFFERENCE!

My vacuum advance hookup point is between the inlet on the turbo and the SU.
I thought there maybe some amount of vacuum at this point even at wide open throttle.

Hears another good read to do with timing

http://www.badasscars.com/index.cfm/pag ... /prd76.htm

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=============DATSUN 1600, NOT JUST TRANSPORT FOR YOUR GRAND MA================

thats a good read

yeah,having your vacum line there would have vacum all the time

_________________
68 510 - soon to be restored into a replica 68sss
69 510 - current build - L20b turbo
91 GT turbo legacy
GET THAT DATSUN DIFFERENCE!

I may just put it on the inlet manifold if it's even worth having it at all.

I'm just trying to find a twin point dizzy at the moment mite have to buy that one on Ebay.

_________________
=============DATSUN 1600, NOT JUST TRANSPORT FOR YOUR GRAND MA================

I have to go through my stuff tomorrow,so i will have a look out 4 a spare but its a long shot

_________________
68 510 - soon to be restored into a replica 68sss
69 510 - current build - L20b turbo
91 GT turbo legacy
GET THAT DATSUN DIFFERENCE!

OK I bought the twin point that was on US E bay so it should show up in a few weeks with new points cap and condensers.

I am thinking a 4 to 5 PSI hobb's switch will work fine with it and 7 degrees maybe 8 will be a good start for retard, with a max total advance of 28 degrees of total advance under boost.

I am also looking at having a play with some parts I have laying around in the shed.
I have some Mitsubishi Cordia bits dizzys, E101 ignitor, S2BB electronic dizzy.
My plan is to use the S2BB Dizzy and modify the diagram from the Cordia dizzy to fit or modify the Blue bird one to be dual reference.
And use the Cordia E101 ignitor and a knock sensor.

_________________
=============DATSUN 1600, NOT JUST TRANSPORT FOR YOUR GRAND MA================

cool,sounds like a plan.keep us updated how it goes,I am a few weeks off from getting my motor built and in car,then i can't start playin with these dizzy combo's

_________________
68 510 - soon to be restored into a replica 68sss
69 510 - current build - L20b turbo
91 GT turbo legacy
GET THAT DATSUN DIFFERENCE!