"%TPS to enable WOT (Normal)"
"%TPS to enable WOT (Hot)"
How hot is hot? Why are the values in the "hot" table so much lower than the "normal" table?

"Cool Compensation Spark vs Load"
Is this based on coolant temperature, or air temperature? Since my car detects knock and retards spark when it's hot outside and not when it's cool (none in the morning, some in the afternoon), is this a good place to try to compensate for that? The air temperature is quite different, but the coolant temp's about the same.

What can I expect (in terms of behavior) if I set the %TPS for WOT very high so that the car never goes into WOT mode? I suspect I'm in WOT mode when I'm detecting knock and retarding the spark, so should I be working on the WOT tables to solve the problem or the main spark table?



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'87 IROC 5.7l TPI - original owner!

 

There should be a Constant to determine at what Temperature is considered "HOT" for PE. I cannot say for sure on MAF, but there definitely is on SD. If you cannont find the constant for MAF, then it is most likely not defined by TunerCat, as many of the Constants that exist for SD also exist for MAF. It is just that they are not defined because there are not as many MAF owners "digging" into the code as many of us SD guys do.

Regarding the Spark Compensation Table, it CAN be for Coolant as SD has a similar table and it relates to "Start Up" and what the Coolant Temp is while in "Open Loop".

When I did a search through the MAF hacs on the all the things affected by the MAT, only the EGR shows up. On MAF systems, the MAT seems to be a really minor player. It appears to do nothing for correction for Fuel and only affects the EGR.

On SD cars, the MAT DOES affect Fuel, but does nothing for Spark. According to Bruce (Grumpy), on the GNs, the MAT does appear to affect the spark, but that is one of the few ECMs of our "vintage" that appears to do this (until someone else positively identifies another).

The MAF controls a lot more than just air flow. It is suppose to also compensate for humidity, but according to the "experts", it does not seem to do a very good job.

 

The "hot" temperature for MAF cars is 248 degrees F. The values are lower so that you go into Power Enrichment (not just WOT, a mislabel by TunerCat) sooner, which will help keep the engine from overheating and/or knocking.

The Coolant Compensation table is based on coolant temp and is used to add spark advance when the engine is warming up, and sometimes remove it when the coolant temp and engine load are high.

If you set the %TPS for WOT too high, you'll lean the engine out, introducing the possibility for knock, and probably burn a hole in the piston if you run too lean too long. If you're getting knock and the subsequent spark retard while in PE, then you need to lower the values in your PE spark advance table (or in your main spark advance table).

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Greg Westphal
'87 IROC 355TPI/A4

 

I haven't looked at the most recent TDF from TunerCat. But if you are unable to find this constant, contact TC about adding it for you.

TunerCat is very "progressive" and rely on feedback from their users as to what is useful and what is not.

I have forwarded "modified" TDFs to TunerCat before that I have found useful in my tuning on my SD 7730 and explained to them why they are useful. TunerCat has been very receptive to adding these constants and tables to their standard $8D TDF (until we hit the maximum number of allowable constants on their previous version).

This is why TunerCat recently updated they program, so more "goodies" can be added to the TDFs; like the $8D.

Also, I know people that did not have the ability or software to modify the TDF for a constant/table they wanted and TunerCat was very receptive to adding those.

There is a LOT more in these TDFs than TunerCat has defined. The ones that are not defined is generally because they really do not need (or should not be) altered. But, when people point out that they need the constant and/or the benefits of the constant, TC is more than happy to add it.

The only TDF (for us 3rd Genners) that was not being updated for a while was $8D, due to the number of constants limitation. But, now that the limitation has been increased, I think we will be seeing a lot more changes to even the $8D TDF.

 

Yes, I agree. When I first started using their software, I found a couple of bugs and needed a couple of constants added. They kindly made the corrections, added the constants, and sent me an updated TDF. This process took place two or three times. I'm quite impressed with their service and responsiveness. I'll not push my luck, there. I'll only ask for a revision when I really need it.



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'87 IROC 5.7l TPI - original owner!