I was thinking a little bit about dyno tuning my car for the summer once I get the wideband on it... I noticed before when I would street tune my car on a hot day, that when the temps dropped at night, the car would start to lean out quite a bit... Never detonated it, but it was definately running significantly leaner when it was say 30 degrees cooler outside...

What time of day or temperature would you recommend tuning it at?

 

your IAT will compensate for it

 

Tuner should keep in mind the ambient conditions and ALWAYS TUNE FOR WORSE CASE.

With that said, it's safer to tune at coldest temps...but...

If we're talking about a system (i.e. stand-alone EMS) that can map air temp, then the widest range of ambient temps would be "best".


-Ted

 

I don't know if you're limited like me to the stock ECU and an S-AFC.
I try to tweak the fuel on cold mornings, to keep from getting into trouble later.

I gotta get a wideband.
Trying to tune this car: I feel like I'm running toward a cliff in a fog.

 

That's why the ECU has temperature compensation maps. You'll be wanting to adjust the corrections based on intake air temp and coolant temp (though the most important measurement is intake air temp). With these the car should be safe in ANY condition.

I personally find it easier to tune when it's warm out. Mostly because for the first little while it's easier to get the car started and idling (without having to deal with cold start settings) and the load maps taken care of (so the owner has the horsepower number to brag to his/her friends). Then when the weather gets cold the air temp correction and cold start can be tuned.

Of course lately it's been cold out so basically I've been doing the opposite.

 

Thanks for the input guys... Like SureShot, I'm limited to a chipped ECU and SAFCII... I also have the cold start assist removed, so that's really not an issue for me... I guess I'll tune somewhere around 60deg so when it warms up I'm just running a little rich, but it's stoich at night (when I do most of my driving anyways)... Temps are fairly mild here, so in the summer it fluctuates from 60-70deg to 80-90 during the day...