More Precision in MAT and Coolant Maps?

Maddog6961 · Post by **Maddog6961** » Fri Jan 18, 2008 3:06 pm

What stops there from being more data points in the MAT correction map? I would like more than 6 points to be able to tune my MAT correction map precisely. I can get it sort of close +- 0.5 AFR with the current map, but I don't think 6 points is enough to tune temps from 20 degrees to 140 degrees. Could someone explain this to me?

The same goes with the warmup/coolant correction map. I don't use my warmup settings as only warmup. I have been using it as a full coolant correction map, and I would like to know what keeps us from being able to have more correction points.

rufusbooth · Post by **rufusbooth** » Fri Jan 18, 2008 4:09 pm

If I had to guess it is to save memory space. I believe that the code interpolates the locations between points to smooth out the curve. That being the case there is less to store and will free up room for other features.

If that is the case there is probably no reason that it could not be done other than lack of storage on the chip.

Someone please correct me if I am wrong.

Cheers,

Rufus

Post by **muythaibxr** » Fri Jan 18, 2008 4:43 pm

We have linear interpolation which makes it unnecessary to have more points than we do

Also, having linear interpolation allows us to use less points, saving flash space.

Ken

Maddog6961 · Post by **Maddog6961** » Fri Jan 18, 2008 8:43 pm

Is there any desire out there besides myself to get more points for finer adjustment of the MAT correction map? I understand interpolation and memory usage, but I personally believe its more important to have accurate fuel and spark control over extra features. I think the extra features are cool, but in my experience, MS still cannot replace a stock ECU in terms of accuracy and consistancy.

mops · Post by **mops** » Mon Jan 21, 2008 8:29 pm

Maddog6961 wrote:Is there any desire out there besides myself to get more points for finer adjustment of the MAT correction map? I understand interpolation and memory usage, but I personally believe its more important to have accurate fuel and spark control over extra features. I think the extra features are cool, but in my experience, MS still cannot replace a stock ECU in terms of accuracy and consistancy.

yes, possibly.
the right way to fix that is to have good sensor in good location. ask me how i know...

Maddog6961 · Post by **Maddog6961** » Mon Jan 21, 2008 8:34 pm

Where do you have your sensor now? I have mine right before my TB and I am using a GM sensor.

6040solder · Post by **6040solder** » Mon Jan 21, 2008 11:55 pm

close to the front of the car if possible such that ambient air flows across it on the outside.

this was a very common issue pre these tables existing at all.

in an NA engine, near the filter entrance would probably be pretty good, in a turbo vehicle in the pipe out of the intercooler as close to the cooler as possible. mines about 2" inside the front panel of the vehicle, i had no issues like that at all.

mops is correct there. the oems don't use them like we do.

Maddog6961 · Post by **Maddog6961** » Tue Jan 22, 2008 4:18 am

Does this properly compensate for hot startups where the intake manifold is heat saturated?

6040solder · Post by **6040solder** » Tue Jan 22, 2008 4:23 am

consider how many cycles it takes to ingest that hot air and you'll see that its gone very quickly and doesn't matter.

if your plenum is pretty big, say 2l on a 2l engine, all that hot air and another litre down the intake tube is gone in 3 revs which with cranking at 180rpm is 1s. I believe there are settings to account for after/during start richness anyway, whereas a wrong reading while you are driving is impossible to deal with well given the tools you have.

Maddog6961 · Post by **Maddog6961** » Tue Jan 22, 2008 4:47 am

Sounds good...I'll give it a shot and see what happens. Thanks for your help.

Maddog6961 · Post by **Maddog6961** » Tue Feb 05, 2008 3:09 pm

So I still have varying idle AFRs after a warm startup. I moved my sensor way away from the engine to prevent heat soak but still after my intercooler. I'm not so sure that this is air temperature related after all.

After a warm startup, I will go lean until I have driven the car around for a bit, and then I can get back to my target AFRs. Any ideas here?

Post by **muythaibxr** » Wed Feb 06, 2008 11:43 am

Can you post a log of this happening?

Ken

Maddog6961 · Post by **Maddog6961** » Wed Feb 06, 2008 5:54 pm

I may retract my statements...I think quite a bit of playing with BIN values and VE numbers has fixed my idle problems. I am suprised at the amount of VE change that can occur at low rpms and low map settings. My idle seems to be consistant now, but I will report back if I am having any additional problems.

On a hot restart, I was at a lightly higher map reading than normal (5 kpa or so) and I to increase my VE values a bit to compensate for that.