... than say 90 deg outside temp? Obviously, the air will be more dense, but is it enough to worry about?

 

more power just make sure you have a heater or your pressure will suffer

 

Your going to need more fuel. It will be leaner. It depends on how it's tuned and how close to the lean side you are now. I hurt a motor spraying at 35deg., sometimes you learn the hard way.

 

Correct.

The only differences will be the car will run leaner than at 90 degree weather.

To give you an idea. On Moes supercharged car he has to retune it when the Texas summer hits because the car goes rich from the hot himid air.
Dave

 

Well said and I agree, with one addition, the dry guys will be fine as the MAF will automatically adjust for temp.
Robert

 

You can spray in any degree weather all you have to make sure is that the bottle is at the right temp.

 

Very true, but do you have a set equation, otherwise, it's just a guessing game and more trouble than it's worth.
Robert

 

Would temp make that big of a difference on a wet hit? I was of the impression that nitrous cars basically make their own atmosphere by injecting the nitrous. The O2 will always be the same based on nozzle size and related directly to the fueling side. So a 250hp hit should always be 250 no matter what the ambient air is. The intake air, though less dense in 90* air, will have the appropriate fueling via injectors based on MAF reading. This would cause less power yes but not cause the a lean condition.
Is this a fair assessment or am I wrong?

 

I think it's a fair assessment, on n/a cars with n2o running a MAF. The MAF does read temp/density.
Robert

 

My experience is this. I have been running a wet NX EFI plate kit on my fox body bracket car a long time. I run a wideband on it and really have it dialed in for consistency. In FL here it's usually hot and muggy, whenever it does get cold I have to add more fuel in, by upping fuel pressure, and take out 1deg. extra timing to get the same w.b. readings and ground strap color lines on my plugs. Bottle pressure is the same, etc. So yes to some degree nitrous makes it's own air, but you also have to factor the oxygen density of the incoming air being mixed in .

I lost the motor on my T/A spraying a dry kit. foolishly w/out a wideband to monitor it. I had run about 30 bottles through it so I got comfortable. One night it was cold for here, like 35deg., I sprayed it and it got lean and hurt cylinder no.7. I think I was already on the edge of the fuel pump and I exceeded the fueling limits on the cold night. I will always upgrade the pump and run a wideband on any car I spray now for sure. I guess running literally 500-600 bottles of nitrous through cars over the years w/out ever hurting something can make you think your always gonna be fine, but it isnt always the case.