[LightningWhite]

I've asked around on a few forums and still no answer. I'm looking to upgrade my ignition for boost. I'm looking for a box to retard the timing based on the amount of boost...the only problem is these boxes use the map sensor to measure the amount of boost for retardation. Mine is a 91, so it doesn't have a map sensor. I've been looking at MSD 6btm, similar summit and mallory boxes to the 6btm. How would the box measure how much boost is in the system? Has anyone hooked up an ignition box for boost and how did you do it?

 

[89coupe]

91 has a MAP/BP sensor

MAP=BP same candy different name. Should be located on the firewall behind the Intake with a 3wire connector on it.

91 just doesnt use the Vac line ran to the MAP/BP sensor

 

[lxarlo]

91 has a MAP/BP sensor

MAP=BP same candy different name. Should be located on the firewall behind the Intake with a 3wire connector on it.

91 just doesnt use the Vac line ran to the MAP/BP sensor

not so much. MAP sensor measures intake manifold vacuum, and gives the pcm an idea of what load the engine is under for speed density applications.

the BARO, reads what it suggests, barometric pressure, or in other words, it tells the pcm the altitude the vehicle is operating at.

Both sensors help to calculate the appropriate amount of fuel to deliver.

The MAF replaced the MAP sensor.

Try an MSD 6Al box.

 

[89coupe]

Believe me I know the difference in how they work. But regardless of that, Its the Same sensor, just with different functional purposes between MAF and SD.

Same sensor MAF= no vac line
Same sensor SD= vac line

Therefore MAP=BP in its external state

 

[LightningWhite]

I understand that they are both essentially the same thing and serve the same function. But how would I hook up an ignition box to retard timing based on boost? I know the 6al doesn't retard timing, but I've seen someone before with a Vortech Boost controller box with the 6al, I was just hoping to be able to use one box.

 

[EagleAutosports]

You want the MSD 6BTM, it has the boost timing inside the box itself where the 6AL needs an add on.

MSD 6-BTM Boost Timing Master - 6462

 

[lxarlo]

Believe me I know the difference in how they work. But regardless of that, Its the Same sensor, just with different functional purposes between MAF and SD.

Same sensor MAP= no vac line
Same sensor SD= vac line

Therefore MAP=BP in its external state

look the same, yea. perform the same function, no.

 

[89coupe]

look the same, yea. perform the same function, no.

87 SD mustang with a MAP sensor hooked to VAC. Convert same 87 SD mustang to MAF, keep same MAP sensor, just remove VAC. every MAF conversion Ive done, and seen done, and listed as how to do, Reuses the same MAP/BP sensor. SAME SENSOR can be used both ways, MAF or SD

 

[lxarlo]

87 SD mustang with a MAP sensor hooked to VAC. Convert same 87 SD mustang to MAF, keep same MAP sensor, just remove VAC. every MAF conversion Ive done, and seen done, and listed as how to do, Reuses the same MAP/BP sensor. SAME SENSOR can be used both ways, MAF or SD

hmm, never thought of it like that. but you still have to change the processor which infers the information differently. But in that respect i suppose you are right.

 

[89coupe]

Yes ECM needs to changed. My only point was to say it Dual Purpose switch. I measures Both MAP and BARO pressures. In a SD system when the engine is first turned on(not cranking or running) The MAP/BP sensor takes a BARO reading. It also updates this reading at a WOT state.

Then the sensor measures Manifold Absolute pressure when the car is running.

Barometric pressure minus Manifold vac = Manifold Absolute Pressure.

Anyways, this was in no way and arguement, just a discussion in my book. We are still friends by the way. :happydancer: Thats gotta be the coolest smiley on the site.