Winter Vs Summer tunes and performance.

[lamrith]

Hey all!  Well summer is approaching (read here for some) and with it comes better fuel.  I know my car sure seems to gain seat of the pants HP in the winter when the temps are cooler, in the winter months.  I have always attributed that to the colder IAT2 temps, it routinely hits a max of maybe 100* tops and cruising is in 70-80's in the winter.  In the summer on hot days like today it is running 130-135 cruising and over 160 sitting at idle. 

I had my car tuned in cooler temps as that happened to be when I bought it and was getting tuned and I think it shows in how it runs, it is just a rocket in sport mode during the winter.   However I never had a tune done in the summer months which leads me to my question.

Is it worth it to have a summer tune?  Is the quality of fuel so much better in the summer that with a tune will offset the huge temp increase and put out more power than a winter tune running summer fuel?

[derfdog15]

I think the only big gain I'd see would be better fuel trim/efficiency. Maybe a few more HP but I ran a winter tune all around, actually had AJP fatten the tune up to allow for it to be as hot as possible in the winter. I would talk to him about pros and cons to be honest.

[AJP turbo]

I guess I could talk myself into both scenarios. I think it may come down to your actual local fuel quality...If your summer fuel is only marginally better than your winter fuel then a bit more boost might be negated by the extra heat and the spark that gets pulled due to IAT compensations.

Those cool temps really do make the car feel great because the normal IAT comps would pull about 5 degrees from 100 to 150 degree manifold charge temps(IAT2)

So if it's really cold out and say your IAT2 is only 80 degrees at WOT that would be like getting 7 more degrees of spark and that would be real power you can feel.

Shoot me a current log if you like.

The beauty of the spark logic in the ecoboost though is as long as the spark tuning is close and the logic isn't butchered then you will always run the right spark and not leave much if any power on the table.

[lamrith]

I guess I could talk myself into both scenarios. I think it may come down to your actual local fuel quality...If your summer fuel is only marginally better than your winter fuel then a bit more boost might be negated by the extra heat and the spark that gets pulled due to IAT compensations.

Those cool temps really do make the car feel great because the normal IAT comps would pull about 5 degrees from 100 to 150 degree manifold charge temps(IAT2)

So if it's really cold out and say your IAT2 is only 80 degrees at WOT that would be like getting 7 more degrees of spark and that would be real power you can feel.

Shoot me a current log if you like.

The beauty of the spark logic in the ecoboost though is as long as the spark tuning is close and the logic isn't butchered then you will always run the right spark and not leave much if any power on the table.

Thanks Brad!  Anyone know if we are into summer fuel yet?