I see that you rescaled the ECT axis on table 44002, which makes sense to me. But, doesn’t having the 180 and 185 f columns set so low prevent the fans from running at all? It’s my understanding that if you increase the values in those cells, you’re telling the fans to run at a higher rate at any given temp range. Is my logic backwards…am I misreading the table description in HPT?

 

Higher numbers do increase fan speed but in some cells you lowered them.

And as Saleen said, for best results you’d need to change the axis. With the stock 190 thermostat I’d have them on 100% by 205.

 

With a stock t-stat there’s not much reason to have the fans on at all at 180-185 because the water isn’t circulating anyway.

 

I have it set so low at 180°F and 185°F because I have been targeting an operating temperature in the 180-190°F range. With very low ambient temps, the stock fan and shutter strategy caused massive temperature swings. In the winter, it could take an hour for my truck to hit steady state temperatures due to overcooling as my ECT would drop to 150-160°F every time the fan kicked on. With my current settings, I have very stable ECTs while idling and driving around in freezing temperatures.

Higher values in the cells of 44000, 44001, and 44002 give you higher fan speeds and increase your cooling request as seen in table 27152. On my truck I couldn't get good results until I made large changes to 27154. That tables was causing my grill shutters to stay mostly open in freezing temperatures and was a big part of the overcooling I experienced. When it comes to getting the cooling request you want, 44002, 44001, and 44000 all need to be changed as any one of these tables could keep your fans running at times when you don't want them on. Initially, table 44000 was preventing me from hitting my desired minimum fan speed of 0% in freezing temps when my ECT was below 185°F.

 

Who would’ve thought that just the fan settings could get so complicated. 🤪😂

Y’all are a wealth of knowledge and I am like a sponge. Thank you both.

 

I feel like a lot of the changes we need to make seem simple at first and quickly become something far more complicated than what they initially appeared.

 

Absolutely. It’s like every aspect of the tune becomes a science project. I’ve been working on the base downshift table for weeks and probably flashed my truck 15 times yesterday. I might be halfway done now.

 

I have 4 sets of base up and down shift tables put together. Each one is progressively more aggressive. I can share if you’d like.

 

No, it’s not that. I’m running a Roush nitemare using the Roush OS and it does some odd things. Ive used the same exact data set (upshift, downshift, coastdown, tcc slip, and tcc unlock) for both tow and base modes and it acts totally different. Yes yesterday I discovered that the 102% app row does nothing (makes sense) but the 100% app row affects it at all app’s (makes no sense). I have no explanation as to why this may be, but changing one single cell at 100% app would affect tipin downshifting as low as 20% app. I did find in pcmtec that tipin can trigger downshifts but only in SST mode.

 

So, for all season driving, stock CAC, do these values seem reasonable? I have not adjusted the A/C head pressure table as I do not understand how it works.