Why is my warm RAF values lower than stock?
11-12-2005, 09:24 PM
#1
Why is my warm RAF values lower than stock? I've been meaning to ask this for a while.
I used the new PID in HP Tuners 2.0 to get my Idle Air table in line.
- I started the car when it was cold
- I made sure the fans didn't come on at all by tuning them off
- I let it get up to 220 degrees and then turned the fans on.
Since I have a cam, you would think that my RAF numbers would be higher from 177 and on.
For my car, from 177 degrees on up, I'm at 6.80 and it idles fine.
My cam specs are: 226 222 116 LSA My car is also a M6.
My TB is home ported and has a stock TB blade hole. When you hold the TB up to the sun or a light, almost no light can be seen around the rim of the TB blade, just like stock.
My cold values are a lot higher than stock but it's just the warm values that are lower, it just seems weird to me....
I used the new PID in HP Tuners 2.0 to get my Idle Air table in line.
- I started the car when it was cold
- I made sure the fans didn't come on at all by tuning them off
- I let it get up to 220 degrees and then turned the fans on.
Since I have a cam, you would think that my RAF numbers would be higher from 177 and on.
For my car, from 177 degrees on up, I'm at 6.80 and it idles fine.
My cam specs are: 226 222 116 LSA My car is also a M6.
My TB is home ported and has a stock TB blade hole. When you hold the TB up to the sun or a light, almost no light can be seen around the rim of the TB blade, just like stock.
My cold values are a lot higher than stock but it's just the warm values that are lower, it just seems weird to me....
11-13-2005, 10:59 AM
#4
Originally Posted by soundengineer
thats normal....
even on stock cams I do Idle RAF...and its lower across the whole range usually
sometimes I wonder what th ehell gm was thinking and whre they found teh guy to do the math on some of these things... :\
even on stock cams I do Idle RAF...and its lower across the whole range usually
sometimes I wonder what th ehell gm was thinking and whre they found teh guy to do the math on some of these things... :\
GM isn't stupid.
11-13-2005, 11:42 AM
#6
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There are a lot of things that affect your running airflow numbers:
1) cam
2) throttle body and/or set screw adjustments
3) desired idle rpm
4) sometimes idle ignition timing from what I have seen
If you have messed with any of those then you need to look carefully at your table. With my cam, idle rpms bumped up a hair, a little more timing, and many cranks on the tb set screw I saw most of my airflow increases under normal operating temperature, with less when warm.
1) cam
2) throttle body and/or set screw adjustments
3) desired idle rpm
4) sometimes idle ignition timing from what I have seen
If you have messed with any of those then you need to look carefully at your table. With my cam, idle rpms bumped up a hair, a little more timing, and many cranks on the tb set screw I saw most of my airflow increases under normal operating temperature, with less when warm.
11-14-2005, 01:53 PM
#7
I used the RAF sheet this weekend. I made the change suggested by the spreadsheet and my STIT came down to near zero while LTIT remains at -3. If I pull 3 from my RAF table, I'd be under 6 when hot.
I noticed that after I changed the RAF table, the Desired Air flow target dropped by almost the amount of the change. I did not make any other changes in the warm operations that would have influenced the idle.
I noticed that after I changed the RAF table, the Desired Air flow target dropped by almost the amount of the change. I did not make any other changes in the warm operations that would have influenced the idle.
