Are there any pros or cons to the weather when tuning your car? I'm wondering because I'd like to do some VE tuning on my car but not sure if the -10C weather will affect it. Thanks in advance.
colder weather, denser air, more fuel requirements, more power
basically it's a worst case scenario for the fuel requirements. if it can handle it in the cold, it can handle it in the heat. might need a few minor adjustments to be perfect in the summertime but it should be pretty spot-on.
2001 Olds Alero (LD9)
650 whp / 543 ft-lb
@turboalero
the ECU factors the air temperature when its calculating how much fuel to use, so thats fine. you might also see less KR with cold air temps.
14.82 @ 97 mph
No, the VE tables and all fueling is based solely on MAP vs. RPM.
IAT is only used in spark correction, and only if the air is REALLY hot.
2001 Olds Alero (LD9)
650 whp / 543 ft-lb
@turboalero
Jason Z24 wrote:the ECU factors the air temperature when its calculating how much fuel to use, so thats fine. you might also see less KR with cold air temps.
LESS knock, let's see a boosted car will see more knock due to the more dense air being easier to compress thus more air is introduced into the equation. Point in fact, a tune that I did in late May had 0 KR, but in Feb w/ temps significantly lower there was 8 degrees of KR. A slight adjustment in the spark tables and this is corrected. Personally I won't touch a tune unless it's at least 60*F outside. Another false in this thread is that the VE tables are only based on MAP vs. RPM if you are running the GM reflash, otherwise it's TPS vs. RPM. There is a belief that IAT does have something to do with our tuning, but we do not have access to these tables.
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4 Cams...32 Valves...5 Liters...This Could Get Fun!
thanks for the info guys. I think i'll do some tuning but I will be sure to tweak it if it needs it when the weather warms up here.
On a side note... Does anyone know where to find a decent trans tune for a 2000 2.4 4spd? I found one on the HPT forums but its for an 05 eco. The charts have different torque values so I don't think it will work.
Use the GM auto reflash, tranny settings. Seem to work well.
FU Tuning
Only problems ive ran into with the SC tune is my shifting from 2nd to 3rd gear
Seems to get hung up going into 3rd Gear
Sucks at the Track
sUiCiDe wrote:Only problems ive ran into with the SC tune is my shifting from 2nd to 3rd gear
Seems to get hung up going into 3rd Gear
Sucks at the Track
We have not had a problem at all.
FU Tuning
John Higgins wrote:Use the GM auto reflash, tranny settings. Seem to work well.
I'll give it a shot and see what its like. Thanks
one reason why i wouldnt tune right now... winter gas.
winter gas is @!#$ compared to whats available in the summer time. the additives they put in for the winter time will not help in any way at all for trying to have a summer compatible tune. it may not hurt it, but i would just wait a few weeks before doing your VE tuning.
as for the auto and their shifting, mine runs fine. no hang ups at all in the shifting and nice and sensitive to down shifting.
1997 Cavalier Z24
Bomz Short Ram Intake
Vibrant Cat-Back
KYB GR2 Struts
Goldline 1.75" Springs
RK Sport Upper Insert
RK Sport Lower Dogbone
Custom Tune by Shane @
innovativetuning@rogers.com
15.647 @ 88.02 MPH
whitegoose wrote:one reason why i wouldnt tune right now... winter gas.
winter gas is @!#$ compared to whats available in the summer time. the additives they put in for the winter time will not help in any way at all for trying to have a summer compatible tune. it may not hurt it, but i would just wait a few weeks before doing your VE tuning.
as for the auto and their shifting, mine runs fine. no hang ups at all in the shifting and nice and sensitive to down shifting.
Good call on the winter gas. I hadn't thought of that. Up here "tuning weather" is more like to 2-3 months away and I'd like to have some knowledge with HPT before i start tuning for my supercharger.
start doing some datalogging. dont even bother tuning until you become good with logging. the logging portion of HPT is an invaluable friend.
1997 Cavalier Z24
Bomz Short Ram Intake
Vibrant Cat-Back
KYB GR2 Struts
Goldline 1.75" Springs
RK Sport Upper Insert
RK Sport Lower Dogbone
Custom Tune by Shane @
innovativetuning@rogers.com
15.647 @ 88.02 MPH
im a believer that IAT is compensated for with repect to fueling. I tuned my cav in sub 32 degree weather. we had low 60 degree weather today, and my AFR's did not change in PE. It may be different or more dramatic for boosted apps, but i'm ALMOST sold that n/a cavs can compensate for temperature changes. We shall see what the heat of summer brings...
