Map editing

[Steve @ VersaTune]

It depends on how much you like to spend on tyres The stock tune reduces requested load in lower gears for traction reasons.

In contrast to the low req load in the 3 MPS, the heavy CX-7 awd auto trans calls for 1.548 load in 1st and 1.737 load in 2nd gear.

[skiptownmcat]

I was always led to believe it was a throttle plate restriction in 1st and 2nd? Which is really the same thing?

Sorry to keep pecking heads but I'm really enjoying getting my head round this motor and I'm hoping all goes well, there are a lot of people in England ready to pull the trigger on this package as we only have 3 tuners in the whole of the uk for the mps, and one of those has a bad rep.

[Steve @ VersaTune]

The throttle plate opening is based on the requested load and rpm. If you request low load, you get a small throttle opening.

[skiptownmcat]

So let me get this straight,
Load tuning uses the MAP pressure for it's calculation, so if barometric pressure is more or less the turbo will automatically increase or decrease boost.
Boost tuning uses the output from the turbo which is relative to barometric pressure, so performance will increase or decrease accordingly?

[Steve @ VersaTune]

Load tuning uses the MAF as the input. Boost tuning uses the MAP as the input.

Load tuning will attempt to reach the target load and will adjust boost as needed to hit that load to the extent that the hardware allows. You get the same power output hot or cold again assuming that there is sufficient flow to support the load target.

Boost tuning does not take into account temperatures or ambient baro or exhaust back pressure. When it's cold you get more power, when it's hot you get less.

[skiptownmcat]

Okay, I think I understand now

Use the req. load gear limit tables to raise load
Make sure the app req load is able to reach that load at 100% (kinda like giving the ecu permission to go that high)
If your seeing boost spikes reduce the BCS DC base in that rev/load range
If you're getting boost cut, raise the map threshold.

[Steve @ VersaTune]

Boost spikes are usually fixed with the req load multipliers. Log the spike and look at what rpms were doing. Find that point on the req load multiplier table for that gear and multiply by a smaller number for more reduction to the req load.

Look at logs to see what normal BCS DC is at steady load for each rpm/tps%. Set the BCS DC base table values to the actual values seen. You'll have to bounce back and forth between the req load tables, dbw tables, and bcs dc base table.

[06Speed6]

I use the req load gear tables to reduce load in 1st and 2nd and I set the other load based tables to the 6th gear table which is the most aggressive.

[skiptownmcat]

Well, just took the ht tune off and installed VT. Had a heart in mouth moment when my computer decided to crash durin initial map backup. Luckily all was ok!!

Flashed the base tune and went out for a drive, did 10 quiet miles and then did a quick blast in 4th(I know I should wait). ltft was at +10.1% and kr was at 3.5-6.7@wot
Not got time to do a log tonight, I'll do a maf cal tomorrow and take it from there.

[06Speed6]

Dang thats alot of kr, the base tune is very safe too.