Hi guys! I'm back into working on my car again with the spring temps rising. My rotating parts are getting balanced this week and the block blueprinting finished by the end of this or next week. So while I am ordering parts from SDPC I need to purchase a 2 or 3bar MAP sensor and plug, but which one? I am gearing up for the switch to the 749 ECM or the $58 code in my 730 for boost fueling and wonder if for any reason I should use a 2bar Part#1625439(I think) over whatever part# a 3bar Map is? Seems to me I shoud just use a 3Bar, but is their a disadvantage in tuning the 3bar for the V8. The need for the 3Bar MAP is ***possible*** in future use but unlikely for the next year or so. I did a search before I posted and yielded no result I could use. Any ancient ECM wisdom to share Grumpy.

 

If your most likely not going to use 3 bar 16+ psi then don't use one. Since a 3 bar uses the same signal range 0-5 volts you will lose resolution in your tables, so if you won't use it then don't. If you will use it get ahold of Brian Green on syty.net and purchase his 3 bar calibration (only way to use 3 bar with $58) and expect to loose table resolution.

 

For up to 15 PSI of boost, run a 2 bar.
15-30 PSI of boost run a 3 bar.

There is no publicly domained code for running a 3 bar setup.
If someone was to do some source code that would min the 3 bar code problem.

While the MAP would sort of be a mechanical filter for the filtering, you can still account for that in tuning.

While the Sy code looks kind of primitive, it is actually a good setup. I'm running a routine similiar to them in my code.

Ancient,
Thanks.........

 

i do belive that the bit flag the sets up the incoming ad Read for either 1 bar or 2 bar simply switchs the multiplier routine. i havent had time to fully digest all the code involved.

my thoughts are to do this properly youd ne to recalculate the input a/d scallers and the baro reads as well as the table scaller for the timing and VE tables as well as the BPW boost multiplier. not hard work just a pain to do. ill be working on the $8f 3bar thing soon and ill pass what i learn onto the 749.

if i only had more time.

if you need a publicily avaiable hac just toss me and email.

 

Thanks guy's. I decided on the 2bar map. I called today to place an order for some sensors, memcals and map connector 15305891 and came up one nuber short on the two bar map 1625439 so it's invalid. Anybody know this 2bar map #. I must have pasted it one digit shy.

 

Order one up for a 90 Turbo Sunbird or Syclone/Typhoon.

 

16254*5*39

 

92GTA thanks but I already ordered 2Bar map sensor: 16009886: $51. I had a GM parts man look it up for me. The connector seemed a little high priced @ 15305891: $37.96 I figure I can find one in a help section or off a boneyard car. AutoZone probably has this stuff for $40 but those guys suck to try and communicate with and some of their parts just blow. I got the required memcal at the same time, so I should be good to go when the stuff rolls in. Now what PSI are Lucas 42lb injector rated at? Anybody need my old FMU

 

A 1 bar MAP connector is different than a 2 bar MAP connector. Don't fret because the only difference is a slot cut into (IIRC) the center pin. A exato knife of razor blade will cure that problem.

 

SATURN5

What are you using for data logging? I've been thinking about TurboLink or Datamaster. I'm guessing TunerCat is the only thing still changing code on the $58?