I have been having problems tuning my VE tables ever since I relocated my MAT and switched to a V6 sensor. The intake is a stealthram and I have the V6 sensor plumbed right before the throttlebody. I have changed my MAT Inverse table in the BIN to match Glenn's values for a relocated MAT. I tweaked some values but it hasn't enabled me to get the desired results. I keep reading Rob's post in the 730 questions area about MAT PW Compensation and it seems like the table I want to modify is the bin counts table. Here is the issue I am having. Yesterday I locked my BLMs to 128 and was going to tune off the INT. But my INT values were all over the place. As an example for 1500 RPMs at 30 Kpa my INT values go from a low of 117 to a high to 136 (CTS 82+/- 5, MAT 43+/-5). It doesn't makes sense when sorting by MAT, coolant temp, or applying the new temperate term in the equation within Rob's post as to why the INT is 117 vs 136. The only thing I can think of is that I am calculating something wrong. I am guessing on the gms/sec because I have never seen a value for a stock AUJP car. What I mean is at 2000 RPMs what is the stock gms/sec and so on and so forth (I realize mine may be different with a modified motor). Typically it seems like I am richer in cooler temps and much leaner in higher temps. But all the posts say to modify the inverse term lookup table not MAT bin counts. I am running out of inverse term to modify. Because my gms/sec at 96 gms/sec+ is already at .06. I really don't see a huge change when I modify these numbers either. The car runs decent but I know it could be better. I'd really rather not put the sensor back in the intake. Before I used a K&N filter on the throttlebody and sensor in the intake and my VE was decent but now I have a 4" intake pipe routed to behind the driver head lights in an enclosed box with a 9" K&N cone filter (sensor in front of TB). Typically on an 80 deg day I see coolant temps while at a steady cruise of 85*C and mat temps hover around 50.

 

I'm wondering if the differences in the inverse table aren't the cause of the problem. The stock AUJP values have much less of a temperature difference then what Glenn used. While I know those values have worked great for him I am wondering if the air temp as it passes through the stealthram is more consistent and needs less correction from the lower end of the gms/sec vs. the higher end. Here is a post with the table values he used. I've been using pretty much the same value but dropping in the higher 96+ values because when I get up to temp that where I seem to hit the 130 +/- BLMs the most. I might try flattening the values so there is less correction between 32 gms through 256.

https://www.thirdgen.org/forums/diy-...advantage.html

 

Here's some info that may help figureing out your problem.
https://www.thirdgen.org/forums/diy-...uys-ditch.html

 

Thanks JP, that link was helpful. I kept reading the stickies on the 730 MAT and it didn't really explain a good way to tune. Grumpy's last post there is very helpful. I did find that messing with the Bin Counts table helps a little. I don't understand why everyone says to leave that one alone. It's based on temp where as the inverse is based on flow. My problem lies in being richer at lower temps and leaner in higher temps. Yesterday I raised the bin counts in the lower temp area and lowered the values in the higher temp. Which leaned out my idle at startup (slightly) through warm up and slightly richened the A/F in the afternoon when my IAT reads about 42 (vs. 28 in the AM). The stock values increment at 12 degs. I've changed that to 8. I think between the 2 tables I *think* I can get it dialed better then it was. But I am far from an expert just learning. So I may be making a mistake but hopefully learning from it.

Also I think I found 1 reason my BLM as well as INT moves too much which makes it hard to tune. I noticed the stock VE tables have areas in the lower tables from about 1300-16000 rpm from 20 to 80 kpa where the VE cells are fairly flat. Mine was not that way. Once I flattened those areas out it settled things down for me and the engine became smoother. Then once I did that and looked at the datalog it showed a few spots (60-70 Kpa) where I needed to lower the timing a bit.