My question is about the use of MSD's programmable timing control box. It says it lets you set timing on the engine from 1/2 degrees to 20 degrees of advance per 1000 rpms. Could you use this in conjunction with the afc hack and then set it up to give you correct timing for a boosted appplication. I know the afc hack causes goofy ignition advance at some points. I do not know where however. Hopefully J. Davis will have something to say about this. I think this could be a viable alternative to a btm and would possible allow you more control over the ecu. Or could the digital multi retard or fixed curve timing computer be used to get correct timing. I am not sure of what needs to be done to the stock timing and at what rpms but I think with one of these msd timing control boxes the hack could become a lot safer to use.

 

Does the MSD box see vaccum/boost?? The BTM is probably a better option if not.

 

No, it doesn't go off a boost dependant signal. It lets you change it however you want over the rpm range. The reason I think it is better because I thought with a afc and btm the ecu will run to much advance before boost. I am not sure though.

 

Nobody else has anything to add to this?

 

so if im reading this right, you wanna add more timing to a system(hack) that adds a **** load of timing to begin with.

 

yup you actually want to retard timing a bit off boost to prevent knock. i'm using a jacob's boost master timing retard device and it work fine. it's very rare to find then now coz they're old models and not being made now but they get the job done. i haven't had it tuned with the car yet though. very soon..

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dirtySOHC's &raquo;</TD></TR><TR><TD CLASS="quote">so if im reading this right, you wanna add more timing to a system(hack) that adds a **** load of timing to begin with.

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No these boxes can either retard or advance timing. What I was talking about for the one that advances is that you set base even farther back and then program the box to make it where it should be.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 88ZCRX &raquo;</TD></TR><TR><TD CLASS="quote">

No these boxes can either retard or advance timing. What I was talking about for the one that advances is that you set base even farther back and then program the box to make it where it should be.</TD></TR></TABLE>

i think i follow you now. i didnt know they retard as well. they adjust timing in RPM increments?

 

You want to pull the largest part of your timing retard at low vacuum through low boost regions with AFC hack setups. It is not RPM dependent.

A regular BTM is linear, where AFC hacks curve the stock ignition mappings across MAP pressure. You can only set up the BTM to hit one point on the timing curve in boost that you want, the rest of the boost event is too much/little retard. The TC is much the same... although it allows you to curve the OEM ignition maps, you can only curve it along the RPM axis, not the MAP pressure axis. You still aren't addressing the problem.

If OBD0/1, buy chip burner, chip ECU for ignition. If OBD2, you deserve to be fucked.

 

Ok, I understand the problem now. You explained that very clearly. So now I have to ponder if they made a btm that could recognize vacuum differences also, then the problem would be solved, correct?I guess I am just trying to put off buying a burner or a standalone too much. It seems I always try to go the long and hard route to make stuff work right.

 

Just to get too technical and confuse everybody, either the BTM or the TC can be used to correct the problem.

Using opamps ($2 LM339, possibly?) you can set the BTM to choose from different ***** (potentiometers) for different amounts of retard at different amounts of boost.

Using an LM2907/LM2917 you could set up a voltage to freq generator and run MAP voltage into the TC in place of RPM feed, and adjust your timing at different MAP pressures-***-frequencies.

I have a few links for you that may help confuse you more:

http://frontiernet.net/~dbipes/msdmod.htm

http://frontiernet.net/~dbipes/msdmon.htm

http://home.teleport.com/~mrri...l.htm

http://members.fortunecity.com/petesbuick/


My take on all the above stuff? All that is a lot of hassle and ******* around, Batronix sells's it's Eprommer kit with software for $69 USD. You can be set up to chip for under $125 after you buy irons and supplies.

 

hmmm maybe i should try this . it seems like there isnt many choices for us Obd0 guys out there. how hard is to tune? could i use say a egt to do it ??

 

What do you mean there aren't many choices for OBD0??

 

let me rephrase that, there isnt any shops around me to tune the few choise obd0 has..