# timming retard, what to buy?



## dburone (Apr 2, 2004)

As some of you may know, i made my E16s (carburated) work with a T25 Turbo, Its running very well, but the device i made to retard timming under boost isnt very good, so im looking forward to buy something.
What should it be?
I need the coil and what else.
My car isnt EFI so no computer to work with.

Thanks in advance!!


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## velardejose (Sep 9, 2004)

Hi
There is this msd module that gives you a certain retard (degrees) per psi you boost
http://www.msdignition.com/tc_18.htm
Or this
http://www.msdignition.com/ignition_7_6462.htm


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## dburone (Apr 2, 2004)

velardejose said:


> Hi
> There is this msd module that gives you a certain retard (degrees) per psi you boost
> http://www.msdignition.com/tc_18.htm
> Or this
> http://www.msdignition.com/ignition_7_6462.htm


How do these work? Do they delay the spark just enough to retard timing?
How does It know the crank angle without an ecu?


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## velardejose (Sep 9, 2004)

They just retard the spark the number of degrees you dial in per psi of boost (1 -3 degrees retard per psi boost)
I imagine as they are ignition modules that's where they take info about rpm from


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## dburone (Apr 2, 2004)

velardejose said:


> They just retard the spark the number of degrees you dial in per psi of boost (1 -3 degrees retard per psi boost)
> I imagine as they are ignition modules that's where they take info about rpm from


I know how to use them, and what they do, but what I want to know is how they work.
Do they delay the spark? How do they calculate the retard degrees?
Let say your are retarding 2degrees for each pound of boost
You are pushing in 5pounds
It should retard 10degrees, how does it know when to make the spark? If it isn’t connected to a crank angle sensor or an ecu, how does it know when?
I guess it could calculate the angle based in the speed of the engine and the stock timing, maybe it can calculate the X time later the spark is equal to Y degrees.


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## velardejose (Sep 9, 2004)

I was thinking about that last week...
As it is an ignition module it has access to the engine rpm
For a given rpm number you can calculate the time needed for a certain degree retard
It has a boost sensor inside the unit where you must connect a boost signal
With both data sources it calculates the desired retard for a given boost
Interesting, it doesn't specify the sensor's boost range...


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## dburone (Apr 2, 2004)

velardejose said:


> I was thinking about that last week...
> As it is an ignition module it has access to the engine rpm
> For a given rpm number you can calculate the time needed for a certain degree retard
> It has a boost sensor inside the unit where you must connect a boost signal
> ...


Is must work like that!!


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