Okay, so this was a little weird to search for. Not sure what to actually call it. If it's been covered before, just link me to it.

I have a GM 3 Bar map sensor, I went bigger because I got it for $20. I was only planning on a 2 Bar. Anyways, I'm looking at my fuel tables and starting to put together a quick base map and such. But here's my 'problem.' There are large PSI gaps on my fuel tables. From one column to the next, it's very large. Crome gives you 14 boost columns max, and with my GM 3 bar that's not very often (2 PSI). On Bre, it has a set number of columns too, which with my 3 bar has large gaps (4 PSI). Using the stock map on either of these looks to be more 'accurate' to me.

I have also read into how, at least how Ben explained the ECU, pulls data from the tables. It uses neighboring blocks and does averaging, ect. Should I be fine with the GM 3 Bar? Or should I get a smaller MAP sensor so the values on my tables are closer to each other?

Thanks.

 

Yes it interpolates between cells.
What you are talking about is the resolution.
You can change the break points of the load columns and rpm rows.

 

Sorry about putting this in the wrong forum. I know more people frequent the forced induction forum.

I was aware I could change the value. I was unaware if I could add more columns. I'll just have to look into that more. Thanks though.

 

I'll keep looking, but is there an easy way to add more columns?

 

Do you plan on running 30 psi?
If not set the last break point to above your max value and interpoolate back to 0 or atmospheric pressure.

For example your max boost is 16psi make it a little higher at 20 psi and interppolate the break points back.

 

^that's the best way to do it. That way you get a little more resolution out of the break points.

 

Thank you, both of you. No, I plan on running about 12 PSI. So I will set my map at about 16 or so and interpoolate back to atmosphere. Did not know it was that easy. I was trying to add more columns, which would have been some coding. It's been awhile since I've written anything for coding. Glad I didn't have to brush up with the hex edittors.

 

I can't seem to edit my last break point. I can't click into the vac/bst and the mbar just resets back to 3093 when I change my value.

EDIT:

Alright, guess you can't change the last one. FORGOT ABOUT THAT! Soon realized I was being dumb. The map needs the maximum to still be the maximum.

What is a safe PSI difference? 1.5 to 2 PSI? Is that acceptable?

 

Okay, so I like to dabble with the tuning. Both Bre and Crome. Since I can actually use Bre right now and compare it to the stock pretty easily.

I know you retard ignition to decrease the chance of detonation. On the map, a smaller number is more retarded, right? What is a good number to start with, for a base map? 1 degree per pound? I have read .75 but then I read some files that came with crome that said DOHC take less retard per pound than SOHC, but compression is important. And my B16A is relatively high-ish-er compression for a boosted motor. It's not 9:1 like the LS motor is. I just want to be safe, make decent power on the street tune before I get to the dyno to do real ignition timing.

 

I do about 1.50 per lb just to be on the safe side.

How are your AFR's looking ? Do you tune by the plug ?

 

I haven't started anything yet. I have a wideband and I'm definitely trying to get a better feeling for reading plugs. I am tempted to get an EGT just so I know my timing isn't going horribly wrong.

But my plan is to set safe base timing, clean up the AFRs, get by with that for awhile, drive to the dyno, get a little more aggressive with the timing and check WOT tuning.

1.5 per lb. I plan on going for 10 PSI max out of this turbo. So that's 7 columns. Plus I still have to leave the last one untouched and go a couple PSI over my planned PSI. Crome lets me go up to 14, but I see a lot of people suggest 6 or 8 for some reason.

 

All this is covered in the manual in my signature. it's free, read it.

 

I have read that a couple times. And everytime I retain a little bit more. I was just working on some things and got a little confused. I realized what I was doing. I was edditng the table the wrong way. I was changing it from right to left, backwards. It wouldn't let me go 1-2-3-4-2-6, where the 2 is what I was lowering since I didn't need to go to 6. Just an example.

I got it fixed.

Thanks!