His correction factors sound about right to me. Here in Guam the night that I made my best run, 15.949@85mph, The DA was about 2600ft. Actually a little more than that, but I'm being conservative. Anyways, that comes out to a 15.4@88mph corrected which is right. Most people in the states run mid-low 15's in a stock ralliart. I run VERY consistent 16.0 times here in Guam and my best was a 15.9 which I was very happy to break 15's in these conditions. My best 60ft. is also only a 2.4 but they don't prep the track here at all and I'm still on the stock RS-A's. So ideally, I'd run very close to a 14sec time on a prepped track near sea level.

anyways, my point is, that's almost a .5 sec correction and my DA is half of what theirs is. So almost a full Second increase sounds about right. Just thought I would voice my opinion.

 

well hate to tell you but the Gm stage II on a stock cobalt ain't gonna add 8-9 mph on your trap. The E.T I might be able to believe a second coming off. Since I've shaved .8 off my oldest time with just one power mod. But i also had a totally different wheel/tire set up and motor mounts. He ain't gonna add more power with the same shitty traction and get a high trap AND a Nice E.T.

 

hey, I thought that the GM Stage 2 was supposed to add a decent amount of power and move the redline up some. for as much as you would pay for it I would hope to gain some decent mph! I would think with the added power and the exra few rpms, you'd gain a good bit in mph! maybe I'm wrong, but doesn't he have fact right there?

 

OK I know what your getting at, but the NHRA correction factors have long been the standard for altitude correction in drag racing. It's even used to set National Records in the Stock and Supe Stock classes.There are different factors for different catagagories of cars and in general as the cars move up in HP and equipment the correction factor is diminished. It's really no different than the SAE correction factors used on dynos.
Plain and simple trapping a 102 is more impressive at 3500ft than at seal level.

"All things being equal" a car that traps 102.0 at 3500ft wil be able to trap (102 x 1.0451 =) 106.6mph at seal level.

WopOnTour

 

that 13.8 is not all you will get with stage 2 if thats the case im done doing stuff to my car because with just gmpp exhaust i am in the high 13s so i beleive that stage 2 should be lower than you predicted "13.8 at best" times. and yes i am on street tires.

 

I agree with you up till a point and understand where your coming from. I don't doubt the 104- 106 trap but when he said 108 i was like umm no.... Plus that 13.3 thing is possible but not probable especially on stock rims and tires. There not gonna wanna put that power down right in the begining since i don't even see a motor mount or TD in his mods list thats all im getting at. Traction and 13.3 or no traction and 108 trap either or but not both like the correction math says, Thats how i feel.

 

i cant wait for my intake and more track time to practice. I only got 3 runs in 1st run I got a lot of wheel hop and i didnt know if i missed 2nd or not so it was a kind of delayed shift but it was my best time here's the stuff:

1st run:
74 degrees
Relative humidity 29
R/T .248
60' 2.293
330' 6.232
1/8th 9.322
MPH 79.43
1000 11.962
1/4 14.159
MPH 103.31

2nd Run(I missed 3rd):
R/T .389
60' 2.224
1/8 9.171
MPH 74.34
1/4 14.228
MPH 100.13

3rd Run(Bad wheel hop):
R/T .375
60' 2.256
1/8 9.285
MPH 78.82
1/4 14.164
MPH 102.43

with that first trap time i should be in the 13s but yeah there be the stage 2 times with my driving intake should be here in a couple days

 

i cant wait for my intake and more track time to practice. I only got 3 runs in 1st run I got a lot of wheel hop and i didnt know if i missed 2nd or not so it was a kind of delayed shift but it was my best time here's the stuff:

1st run:
74 degrees
Relative humidity 29
R/T .248
60' 2.293
330' 6.232
1/8th 9.322
MPH 79.43
1000 11.962
1/4 14.159
MPH 103.31

2nd Run(I missed 3rd):
R/T .389
60' 2.224
1/8 9.171
MPH 74.34
1/4 14.228
MPH 100.13

3rd Run(Bad wheel hop):
R/T .375
60' 2.256
1/8 9.285
MPH 78.82
1/4 14.164
MPH 102.43

with that first trap time i should be in the 13s but yeah there be the stage 2 times with my driving intake should be here in a couple days

 

See, what you all are forgetting or over looking is that those correction tables are for NATURALLY ASPIRATED vehicles only. NOT forced induction. Thats why airplanes have turbos and older WWII planes had SC's! To maintain sea level performance at higher altitudes


Nice times though either way

 

Good catch!
But whether your volumetric efficiency is 25% or 125% the effects of +3500 ft elevation will affect BOTH engines of course, just lessor so in the boosted engine.
I believe the NHRA used to reduce the correction factor by 50% for turbo or supercharged cars in all Sportsman classes other than Top Alcohol.
WopOnTour