Hot weather tunning verse cold weather tunning

[agteacher]

Summer weather--90-100 degrees and humidity same as degrees( sweating in the shade!!!!) We are about 7-800 ft above sea level.
Cold weather--30-65 degrees and humidity GREAT!!!!!

Boost-- around 26psi.
timming-- 21deg.
Fuel-- 93 octane and Alky.
Wbo2--10.7-11.0


This is a GENERAL "rule of the thumb" Question: ADD fuel in Summer and REMOVE fuel in Winter

Reason: I have been watching my wbo2 numbers and they are going a little lean(11.4-11.9 with a couple degrees of knock--reading taken in top of 3rd gear) My tune is the Same tune as winter, I was just wondering if it was because of the "screw-up" weather(tempt.and humidity---air quality) here in Mississippi????

 

[bosted86]

it the other way around. add fuel in winter because the air is denser. summer air is thinner.

 

[slipstick]

Is it possible that the gasoline you have been getting recently contains a percentage of ethanol? If so, it has a lower stoich value than regular gasoline and therefore requires more fuel for proper combustion. Search for a thread I started in this forum on July 7th titled "Higher BLM with 10% ethanol" for my thoughts and experience. Sounds somewhat similar to your experience.

 

[agteacher]

Is it possible that the gasoline you have been getting recently contains a percentage of ethanol? If so, it has a lower stoich value than regular gasoline and therefore requires more fuel for proper combustion. Search for a thread I started in this forum on July 7th titled "Higher BLM with 10% ethanol" for my thoughts and experience. Sounds somewhat similar to your experience.

Thanks for the link:http://www.turbobuick.com/forums/general-turbo-buick-tech/256255-higher-blm-10-ethanol-gasoline.html

I will try and see if this helps.
Thanks for all the replies.

Also, the car has developed a OFF-IDLE stumble........

 

[bison]

Id shoot for 10.5-10.8 with 93 octane and alky. Dont worry about the % of ethanol. You have no way of knowing the actual content. Its on th pump as up to 10%. Just shoot for the same lambda and you will be ok. Add in winter pull in summer. You will not be ok if you have any KR. Anything in 3rd at those boost levels is doing damage. Either increase meth flow, back off boost, or add octane. You better check your pumps if its going lean. Your hurting it.