Long story short

only drive my car in the summer put 1,500 miles a year on it. never driven in weather colder then 60

came home for X mass no snow so i pulled it out of storage. 93 tune.

drove it in 30 degree weather noticed my AFR hits 12.8 but boost is the same at 1.5 Bars my tune is suppose to be 25PSI on93 so I'm 2 pounds under.

now the AFRs hit 12.8 while building boost at WOT then once i hit 4.5RPM my AFR goes back down to 11.5 My dyne tune has the max AFR at 11.2

Should i be concerned?

if i do a 1 2 3 pull all in a row the AFRs stay in the 11s its only when i do a WOT pull in 3rd from 2.5RPM to redline.

Boostin told me to bring the car in but i live 8 hours away so thats a little difficult otherwise they can not help.

when tuning a car it should be tuned for all weather correct? i mean i live in MI so cold weather is bound to happen.

PS the tune was done 2,000 miles ago and my car has seen no changes.

please help.

 

Thetune is going to be the closest when the temperatures and conditions are thesame as it was in the dyno room. Honestly, that is why I like to tune in thefall where the temperatures are more consistent in the Midwest.



Thereare temp vs fuel scales that can change fueling in the colder temps. Mostof all that has to do with warm up and closed loop operation. I would notbe concerned. Sounds like it has a little lean spot to help buildboost or for whatever reason and is amplified by the colder weather. If it goesmuch leaner (13afr) I wouldn't beat on it till you can get itadjusted.



Justmy 2C



MerryChristmas!

 

12.8 is a touch lean during spoolup. 11.5 is fine when in boost. When does your car hit peak boost? If peak boost is 4500, it's probably fine. Hard to say without seeing a datalog though.

 

Being that the air is denser when cold you definitely need to get a winter tune if you plan to rip on it a lot, but like the other guys said as long as it isn't crazy lean you shouldn't have much to worry about if you can manage to drive normally lol

 

thanks for the help sounds like i shouldn't be to worried about it unless i start seeing those numbers at higher RPM.

my car hits full boost around 4K RPM i would say its stock turbo full bolt ons and cams

 

Optimum power is made at 12.5 afr... Usually they're tuned a bit more rich at wot for change of climate /temps/etc. it's slightly lean at 12.8 for spool up but as long as it's below 12 at high boost id say you're good... If it's 12 or 12.5 it will make a bit more power but you're closer to the danger zone. My tune brings me to 11.5 at wot.

 

Why not contact the tuner and send them a log. I'm sure they will tell you if it's safe or not, and can make adjustments for you.

 

Is lean spool enabled in your tune?

 

boosting said they will not do mail in tunes or adjust i asked,,,

im not sure what lean spool is.

i think i may just park it and drive is again in the summer and see how it is once the temps are back up.