I just dynoed today and the results were a little puzzling. The last time I put down 263 peak, it was summer...90 degrees, 90% humidity. Today it was 75 degrees and like 40% humidity....well you would think i would have a stronger dyno, but the exact opposite happend. I was like 20 horses off.

When we looked at the AFR it was running very lean. (14s at some points)

So my tuner said that it was the weather that is making it run so lean becuase we tuned when it was so hot and humid. He suggested we make another map for cooler weather.

I think he is right because when we overlayed my run from before with yesterdays the AF curve is identical just at a point lower. I mean all the little peaks and valleys were the same...its just sitting around 14 where before it was arounds 13.

What do you guys think?

 

you are also going to need to look at the dyno correction. remember the dyno is also correcting for the air conditions. If the temp, humidity, etc are better than the SAE standard, the dyno is going to lower the actual number to bring it back to SAE standards. conversely, in the hot summer air, the corrected dyno numbers will be higher than actual readings.

 

but what about the AFR ratio being off? I dont think the SAE correction would be that drastic....would it?

 

my a/f is drastically different the last couple of days. my air intake temps are about 40 degrees below normal due to the cold wave running through florida. I am seeing my A:F shift to the lean side by about 2 points....

I just went back in to the UTEC and implemented the temp corrections.

 

Where the corrections based on the included formulas effective? Any chance you could post a before and after datalog showing the impact of using those formulas? I'm very interested to hear how effective they are. And also in trying to determine "how much does the temp have to change before the corrections really need to be made?"

Thx!

 

Aww.....ok this makes sense then. Its sooo cold and dry here right now (for Fl anyhow) that my AFR was lean too. Im going in Monday to have a remote switch installed and tune a map for the colder months.

thx for your info.

 

unfortunately, the utec only provides a +/- 10% for the temp corrections.

That is probably great if you happened to tune your car at 25-30*C....then you'd be able to make adjustments above and below that without much trouble.

The trouble comes when you have a tune that is good for 40+*C n (with lots of humidity) and now, I am seeing air intake temps around 16*C and very Dry......I don't have enough room to compensate. UGGHHHH!!!!

 

So then what did you do? Am I going to have to make an entirely new map?

 

I haven't driven the car in the last 24 hours.

I'm going to turn the boost down a couple psi. and fiddle with the temp correction maps a bit more.........

But now, It's time for turkey!!!

 

lmk what you figure out. Im going in for a tune on wednesday.

 

The temp correction in the utec doesn't really work. Nobody uses it. Hopefully when they release the gui for it they will have all the features working properly.Your just better off making a cold weather map.

 

cool. thanks.

 

It definately makes changes, but there is not linearity ot it. Unfortunatley, the UTEC gives you a 10*C window for each correction. That's 18*F...that's too big. And it doesn't scale it either. So, once you hit the temps for the correction to happen, it adds the fuel. If you are only 1* into the correction point, you may be rich......if your are 10* into it, it may be a little lean.

If TXS could allow for the temp corrections to scale, it would work well.

your best bet is to get it tuned at temp that is somewhere in the middle of your driving temps during the year. If you live in an area with extreme temp changes, the UTEC isn't going to provide enough room for changes.

 

Ask any of the tuners here that know the utec. Not one of them use this feature. If you don't believe me ask sharif or mrc motorsports. The feature isn't worth the time or effort now to use it until they refine it. Just make a different map it's much easier and safer.

 

I posted about this thing not that long ago and just recently updated it. My question is this. Sharif sent me a TT base map not that long. Where he's from, this map is no doubt a killer platform to start from. But here, this time of year, single digits are the norm with negative temps right around the corner. However, it's not uncommon for it to be -20 one week, and then next week it could be 25 or better and then fall right back negative again. I have his map saved in position 1, but what should i account for and make changes to once i get into tuning this week? I'm looking for help from people who actualy self tune and not just read about it or have a shop do it. Where i'm from, self tuning is my ONLY option. To be on the safe side, i'm running off stock WG's alone before i attempt to up the boost any. Also, i know A/F readings play a HUGE part to this and have since bought and installed a Tuner Pro-Bosch. It's O2 along with my custom dual 3" pipes go in Tuesday.

 

hey man, i found the temp corrections that they recommend to be way too drastic.


i am sure you can find a happy medium if you tune the car in around 70 degree weather. then you will be good 30 degrees warmer and 30 degrees colder.


good luck with it.