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?

 

Assuming that your MAF is functioning correctly and the tune is compensating for the additional air (denser charge) I can't see much reason for you to have trouble. Do you have a wideband O2 sensor installed so you can check you AFR in those conditions? I'm also assuming that your cooling/heating system is up to par. The engine needs to be in a particular temperature range to run it's best. Sometimes people mistakenly believe colder is always better...

 

Hi... How cold is cold for you... And are you referring to the cold start? Tim