Tuning with humidity....

[1glaserturbo]

Well, it's rather damn humid here and I just got to thinking. How would I tune for humidity? My thoughts are, the less humidity, the less fuel I needed. Vice versa. I'm trying to tune for 20lbs on the SAFc and no matter where I stick it (-18% all the up to -8%) I get crazy knock

Little help would be fantastic!

 

[andymoraitis]

A more accurate description of humidity would be water grains. As the air becomes more humid or water grain count goes up, you actually need less fuel since water displaces oxygen in the incoming air charge. Top fuel tuners will typically add more boost to try and squeeze power out of air with a higher water grain content, but they have tons of fuel on tap. Cooler, denser air is more oxygen rich and more prone to create power so it would therefore require more fuel.

I would suggest that you have your chip set for true 550cc compensation and only use the AFC for fine corrections. As it stands, you're running 8.5:1 on a 1G motor which naturally has a more aggressive timing map. Either have Jeff make you a custom map that peaks at 18 degrees with custom A/F tables or at least get the compensation correct in the chip so that you don't need to constantly correct airflow for varying environmental conditions.

Let me know if that makes sense.

Andy

 

[1glaserturbo]

Makes absolutely perfect since, but sending out my chip is unfortunately OUT of the question....this is my only daily driver

I've gotten it down to where I'll hit 0 counts of knock up until around 5,000 rpms then my MAS reads over 900Hz then knock starts. I've only seen 9 counts because I instantly shut it off when the knock number moves from 0 (just a habit).

S-AFCII settings are pretty good, 3k:-17% (0 knock), 3500:-14% (0 knock), 4200:-10% (0 knock), 4600:-8% (0 knock), 5000:-8 through -3% (9 counts) 5500 and up are -3 also, but I haven't gone that high as of yet.

This is with my setup in the profile and 20lbs of boost.

 

[2gGSX]

9 counts is less than 1* of timing retard which isn't a terrible problem, although not ideal. If you can't afford to send your chip out you could just have him burn you a fresh one--it wouldn't cost that much more.

 

[nightspeed87]

9 counts is less than 1* of timing retard which isn't a terrible problem, although not ideal. If you can't afford to send your chip out you could just have him burn you a fresh one--it wouldn't cost that much more.

good to know because i cant afford to send my chip out either because my car is dd... So with the chip basically you just have to tell them you complete set up down to the details and the chip burner could correctly make you a ideal chip for your set up with no mistakes? Because i wouldnt want to put the chip back in and then suddenly my car blows up because the timing maps was set crazy or something odd you know... And id want actual horsepower proven results so that when i went to the dyno id be impressed ..

 

[2gGSX]

My friend had the same situation with his car being a daily driver. He talked to the guys at keydriver and they're sending him a separate chip, and then he is sending back the chip currently in his car to reduce downtime.

Andymoraitis has a great deal more experience with chips than I do, so he would be the one to ask about these questions. Give the guys at keydriver/dsmchips a call though and they'll help you with everything you need.