How much does the weather REALLY affect performance?
04-23-2001, 10:17 PM
#1
Banned
Thread Starter
Join Date: Jul 2000
Posts: 1,384
Likes: 0
Received 0 Likes
on
0 Posts
How much does the weather REALLY affect performance?
On a supercharged car. When it was cold here the car seemed A LOT faster. Now that it's in the 80s the car seems sluggish and a lot slower. My boost is around the same. Does anyone here have any ets to compare of hot weather runs vs cold weather runs?
------------------
91 Formula 1LE 1 of 46
305 TPI 5speed
1LE/G92/WS6
Paxton SN92 supercharger, Ford SVO 24#injectors, Crane AFPR,SLP airfoil, ported/polished plenum, March alt. pulley,Crane Gold 1.6rrs,MSD coil,MSD6AL (5400rpm limit),Holley 9mm wires,Ac delco R43ts plugs,custom chip,Bosch O2sensor,SLP 1 5/8" headers,SLP catback,shortened shifter,3:73s w/Auburn posi,180* t-stat,JET 195* fan switch, Macewen white face gauges, Autometer gauges, Zoom hi-performance clutch.
------------------
91 Formula 1LE 1 of 46
305 TPI 5speed
1LE/G92/WS6
Paxton SN92 supercharger, Ford SVO 24#injectors, Crane AFPR,SLP airfoil, ported/polished plenum, March alt. pulley,Crane Gold 1.6rrs,MSD coil,MSD6AL (5400rpm limit),Holley 9mm wires,Ac delco R43ts plugs,custom chip,Bosch O2sensor,SLP 1 5/8" headers,SLP catback,shortened shifter,3:73s w/Auburn posi,180* t-stat,JET 195* fan switch, Macewen white face gauges, Autometer gauges, Zoom hi-performance clutch.
04-23-2001, 10:42 PM
#2
Makes a big difference (except in your case 
) I once read 3% for every 10 degrees but that seems a little steep to me.
------------------
87 Formula 350 13.94@96.67
98 Z28 1LE 13.15@107.59
1LE Owners Association
) I once read 3% for every 10 degrees but that seems a little steep to me.------------------
87 Formula 350 13.94@96.67
98 Z28 1LE 13.15@107.59
1LE Owners Association
04-23-2001, 11:31 PM
#4
Moderator
Join Date: Jul 1999
Location: 51°N 114°W, 3500'
Posts: 17,165
Likes: 0
Received 136 Likes
on
114 Posts
Car: 87 IROC L98
Engine: 588 Alcohol BBC
Transmission: Powerglide
Axle/Gears: Ford 9"/31 spline spool/4.86
Temperature isn't the only factor. High humidity and low barometric pressure will also cause a car to go slower.
Supercharged engines shouldn't be effected as much as a naturally asperated one since they are forcing more air into the engine than what is normally available. This can compensate for poor air.
Personnaly I'd guess that the car is running too rich. If it runs well when the air is cold then there's enough fuel for all the cold dense air. Now that it's warm the air is less dense and the supercharger is still forcing it into the engine to be mixed with the same amount of fuel. Since the air isn't as dense, the same amount of fuel is mixing with less air causing a rich mixture.
Lower the boost or lean the fuel down.
------------------
Follow my racing progress on Stephen's racing page
and check out the race car
87 IROC-Z Pro ET Bracket Race Car
383 stroker (carbed) with double hump cast iron heads and pump gas
461 Big Block installed and ready for the 2001 racing season
Best results before the 383 blew up
Best ET on a time slip: 11.857 altitude corrected to 11.163
Best MPH on a time slip: 117.87 altitude corrected to 126.10
Altitude corrected rear wheel HP based on power to weight ratio: 476.5
Best 60 foot: 1.662
Racing at 3500 feet elevation but most race days it's over 5000 feet density altitude!
Member of the Calgary Drag Racing Association
87 IROC bracket car, 91 454SS daily driver, 95 Homebuilt Harley
Supercharged engines shouldn't be effected as much as a naturally asperated one since they are forcing more air into the engine than what is normally available. This can compensate for poor air.
Personnaly I'd guess that the car is running too rich. If it runs well when the air is cold then there's enough fuel for all the cold dense air. Now that it's warm the air is less dense and the supercharger is still forcing it into the engine to be mixed with the same amount of fuel. Since the air isn't as dense, the same amount of fuel is mixing with less air causing a rich mixture.
Lower the boost or lean the fuel down.
------------------
Follow my racing progress on Stephen's racing page
and check out the race car
87 IROC-Z Pro ET Bracket Race Car
383 stroker (carbed) with double hump cast iron heads and pump gas
461 Big Block installed and ready for the 2001 racing season
Best results before the 383 blew up
Best ET on a time slip: 11.857 altitude corrected to 11.163
Best MPH on a time slip: 117.87 altitude corrected to 126.10
Altitude corrected rear wheel HP based on power to weight ratio: 476.5
Best 60 foot: 1.662
Racing at 3500 feet elevation but most race days it's over 5000 feet density altitude!
Member of the Calgary Drag Racing Association
87 IROC bracket car, 91 454SS daily driver, 95 Homebuilt Harley
04-23-2001, 11:41 PM
#5
Banned
Thread Starter
Join Date: Jul 2000
Posts: 1,384
Likes: 0
Received 0 Likes
on
0 Posts
During part throttle/low RPMS ecu is trying to take away fuel. But.............at WOT the block learn data looks like this :
3675 RPMS- BLN 128
4250 RPMS- BLN 128
4850 RPMS- BLN 128
This indicates no fuel is being added or taken away. This means I'm not rich then right? I took this run in current weather. Now I'm really stumped
[This message has been edited by theformula (edited April 23, 2001).]
[This message has been edited by theformula (edited April 23, 2001).]
3675 RPMS- BLN 128
4250 RPMS- BLN 128
4850 RPMS- BLN 128
This indicates no fuel is being added or taken away. This means I'm not rich then right? I took this run in current weather. Now I'm really stumped
[This message has been edited by theformula (edited April 23, 2001).]
[This message has been edited by theformula (edited April 23, 2001).]
Thread
Thread Starter
Forum
Replies
Last Post
3.8TransAM
NW Indiana and South Chicago Suburb
2
10-01-2015 07:47 PM
affect, altitude, boost, density, effect, engine, engines, high, hot, humidity, supercharged, supercharger, temperatures, warm, weather
