BigStuff MAP increments

[Six_Silver]

I read a post about the KPa to PSI conversion for the FAST and saw that the following increments are displayed in the first 10 rows on the FAST:

KPa --- PSI
314 --- 30.8
295 --- 28.1
275 --- 25.2
256 --- 22.4
236 --- 19.5
216 --- 16.6
197 --- 13.9
177 --- 11.0
158 --- 8.2
138 --- 5.3

You can see above that the FAST's increments are about 20KPa.


I just looked at the first 10 BS3 MAP increments and they are as follows:

kpa ----- PSI
307 ----- 29.82
275 ----- 25.18
234 ----- 19.23
200 ----- 14.3
175 ----- 10.68
150 ----- 7.05
129 ----- 4.00
116 ----- 2.12
99 ------- -0.3
90 ------- -1.64

As you can see above the BS3's increments are different (32KPa, 41KPa, 34KPa, 25KPa, 25KPa, etc.)

So comparing the two in PSI, you can see that the FAST has twice as many rows in the fuel and spark tables than the BS3 in the higher PSI range (14PSI or more):

FAST ====== BS3
30.8 ====== 29.82
28.1 ======
25.2 ====== 25.18
22.4 ======
19.5 ====== 19.23
16.6 ======
13.9 ====== 14.3
11.0 ====== 10.68
8.2 ======= 7.05


If they are both setup for a 3-bar map sensor, why is the table so much different? I dont like the 6psi jump between 19 and 25psi, and then the 5psi jump from 25 to 30 psi.

Because of this big jump, the difference between running 25.5psi and 29.5 psi is ZERO points of fuel??!! I will be adjusting the tables based on how much boost I am running but if it creeps or fluctuates for whatever reason I guess thats what fuel correction is for.

Is there anyway to adjust the kPa row or is that hard coded into the BS3? Why would the BS3 designers change the MAP increments if they were the ones that built the FAST and the FAST table is better?????

 

[NastyGn]

James I don't know about the Big Stuff but on the Fast unit you can set the cell rpm range. I would think the Big Stuff can do this also but don't know where to tell you to do it.

You might call Lawrence Conley at Conley's. He does the Big Stuff and might be able to tell you. (281) 540-3278. Call him after 1700 central time and he should be there. I'm sure he would be more than willing to take the time to help you.

Good luck

 

[Quick86GN]

The Big Stuff 3 has configurable Load & RPM axis to enable optimization in the desired range. So the answer to your question is yes the KPA & RPM are configurable.

 

[Six_Silver]

Found it! Thanks Quick86GN. I was poking around the options earlier and must have overlooked it somehow. Thanks guys.