can weather make you loose 4 mph??
#1
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as the title says... last time at the track I ran 108 w/ "decent" weather, but now ran 104 with bad weather.
but 4 mph???? isnt that like 40 horsepower?????
but 4 mph???? isnt that like 40 horsepower?????
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i would say so, i trapped 106 a couple times in 60 degree weather, and this summer the best trap i got was 103 in 95+ degree weather, even on the bottle i lost 3 mph in the 1/4
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I was at the track last night and my trap speed was anywhere from a low of 97 to a high of 102... Granted I missed a gear on the 97, but I had plenty of 'decent' runs with high 90's traps.
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Doesn't really matter the set-up of car. Weather affects it, that's why people pray for high Barometric pressure readings, low humidity and a good temperature (but not so cold it affects traction). Going from close to 0 DA (Density Altitude) to 3000-3500 that we see in Florida can make my car run about 2-3 mph and 2-2.5 tenths faster/slower.
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Originally Posted by fenix99
yea man summers do really suck in florida...IAT's are crazy and the humidity kills the fun.....only a couple more months till it gets cold
wooooooooooooooo
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Derek
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well consider that weather conditions will effect your density altitude, now compare somewhere like houston raceway park (10 ft above sea level) before density altitude corrections to somewhere like colorado here where we have 5800 ft of altitude before density altitude corrections and its not uncommon to see the same car run more than a 1.5 secs slower up here than it would at sea level and thats why you hear a ton of talk about density altitude up here in the thin air, density altitude is determined by absolute barometric pressure, humidity and temperature (i think thats all) so say you're running on a day where its 90* with 80% relative humidity and quite a bit of barometric pressure, this will create a higher density altitude and make it harder to make power this makes the air charge coming in to the motor a less dense air charge and thats not to mention that with the humidity the track can sometimes get a little more slick, now compare that to a day where you have 70* temps 20% relative humidity and not nearly as much barometric pressure this will make it easier to make power because it makes the car feel like its running at sea level where the air has a more dense charge. im pretty sure thats about how that all works, im not 100% on how barometric pressure works other than the fact that its measured in milimeters of mercury usually ona barometer because im not a meteorology major, if im wrong please state corrections
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Every 1000FT difference in DA can be good for a 1MPH/1 1/10th difference in the average F-Body... Our track DA ranges from a very worst of +4000FT DA to a very best -1500FT DA... this difference can easilly result in the car running half a second faster or slower...
http://wahiduddin.net/calc/calc_da_em.htm
http://wahiduddin.net/calc/calc_da_em.htm
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Originally Posted by vmax1500
Every 1000FT difference in DA can be good for a 1MPH/1 1/10th difference in the average F-Body... Our track DA ranges from a very worst of +4000FT DA to a very best -1500FT DA... this difference can easilly result in the car running half a second faster or slower...
http://wahiduddin.net/calc/calc_da_em.htm
http://wahiduddin.net/calc/calc_da_em.htm
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From personal experience I can tell you that 13.5 @ 103 in 95 degrees and humid as hell turned into 13.1 @ 106 in 50 degrees and dry as a bone. But it took one extreme to the other extreme to affect my trap by 3 mph.
Right now I trap 109 on cool nights and 107-108 on hot and humid ones. So possible? Yes. But from my experience it needs to be extreme bad racing weather to extreme good to have that much mph difference on a bolt-on LS1.
Right now I trap 109 on cool nights and 107-108 on hot and humid ones. So possible? Yes. But from my experience it needs to be extreme bad racing weather to extreme good to have that much mph difference on a bolt-on LS1.
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When temp is 55 I trap 117. When temp is 95 I trap114. It makes a difference. Maybe my imagination but I swear in the fall when temps drop a good 30 to 40 degs. behind a cold front,my car seems to feel faster on the street