Hot vs Cold Air temp - tuning Q's
07-14-2008, 04:50 PM
#1
Hot vs Cold Air temp - tuning Q's This may sound like a dumb question, but just hear me out. My car seems more together when the temperatures are extremely hot 95* + outside - ie no exhaust burps, or pops, gears engage smoother, valvetrain is quiet, the rpms band just seems silkier and smoother, no hesitation btwn shifts. However, when the temps are lower the exhaust pops more frequently, the valvetrain is louder, and I get the sewing machine noise. In addition, the gears and rpm band just doesnt seem as smooth.
Now to the question.....since I got dyno tuned in very hot conditions, after driving 3 hours.....is there a possibility my tune is "off" for colder conditions? The car does seem quicker in the cold (denser air charge), but it just seems more choppy, like the tune is off. Any ideas?
Now to the question.....since I got dyno tuned in very hot conditions, after driving 3 hours.....is there a possibility my tune is "off" for colder conditions? The car does seem quicker in the cold (denser air charge), but it just seems more choppy, like the tune is off. Any ideas?
07-16-2008, 02:58 PM
#3
There's not much to say. We have no idea what the tuner has done w/ your car. In colder air, the IAT table should pull less timing. The ECT's may be a bit lower for a while ase well. This will make the car faster, which is what you have described.
Sounds like your VE tables are off (low). This could make it run a bit more rich in cooler temperatures & could cause unburned fuel to burn & pop in the exhaust. Could also be that your plug gaps are off. Did the tuner tune for WOT only, or did he tune for normal driving conditions as well? Does it still pop after 20 minutes of driving? Could just be a start condition until the engine reaches operating temps.. Best thing to do is to call the tuner & explain what is happening. If he's not close, then you can probably send the PCM to him & have the issue corrected.
Sounds like your VE tables are off (low). This could make it run a bit more rich in cooler temperatures & could cause unburned fuel to burn & pop in the exhaust. Could also be that your plug gaps are off. Did the tuner tune for WOT only, or did he tune for normal driving conditions as well? Does it still pop after 20 minutes of driving? Could just be a start condition until the engine reaches operating temps.. Best thing to do is to call the tuner & explain what is happening. If he's not close, then you can probably send the PCM to him & have the issue corrected.
07-16-2008, 04:17 PM
#5
ls-450, thanks for describing that for me, I appreciate your help.
Frost - I know, I was just trying to get a feel from people who do know what they are doing (like yourself) to see if you have run into a situation like this, and possible ways to correct it.
Basically, I had an unfamiliar tuner tune my car, and Im just unsure if he was as thorough, efficient, and maximized gains while being safe as I hoped he would be.
Frost - I know, I was just trying to get a feel from people who do know what they are doing (like yourself) to see if you have run into a situation like this, and possible ways to correct it.
Basically, I had an unfamiliar tuner tune my car, and Im just unsure if he was as thorough, efficient, and maximized gains while being safe as I hoped he would be.
